* [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
[not found] <1821667922.1236806.1528308060822.ref@mail.yahoo.com>
@ 2018-06-06 18:01 ` Zenith432
2018-06-07 1:32 ` Gao, Liming
0 siblings, 1 reply; 9+ messages in thread
From: Zenith432 @ 2018-06-06 18:01 UTC (permalink / raw)
To: edk2-devel; +Cc: steven.shi, yonghong.zhu, liming.gao
Adds support for the following X64 ELF relocations to GenFw
R_X86_64_GOTPCREL
R_X86_64_GOTPCRELX
R_X86_64_REX_GOTPCRELX
CC: Shi Steven <steven.shi@intel.com>
CC: Yonghong Zhu <yonghong.zhu@intel.com>
CC: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
---
BaseTools/Source/C/GenFw/Elf64Convert.c | 166 +++++++++++++++++++++++-
BaseTools/Source/C/GenFw/elf_common.h | 23 ++++
2 files changed, 188 insertions(+), 1 deletion(-)
diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
index c39bdff0..d2f9bb46 100644
--- a/BaseTools/Source/C/GenFw/Elf64Convert.c
+++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
@@ -94,6 +94,15 @@ STATIC Elf_Ehdr *mEhdr;
STATIC Elf_Shdr *mShdrBase;
STATIC Elf_Phdr *mPhdrBase;
+//
+// GOT information
+//
+STATIC Elf_Shdr *mGOTShdr = NULL;
+STATIC UINT32 mGOTShindex = 0;
+STATIC UINT32 *mGOTCoffEntries = NULL;
+STATIC UINT32 mGOTMaxCoffEntries = 0;
+STATIC UINT32 mGOTNumCoffEntries = 0;
+
//
// Coff information
//
@@ -322,6 +331,117 @@ GetSymName (
return StrtabContents + Sym->st_name;
}
+//
+// Find the ELF section hosting the GOT from an ELF Rva
+// of a single GOT entry. Normally, GOT is placed in
+// ELF .text section, so assume once we find in which
+// section the GOT is, all GOT entries are there, and
+// just verify this.
+//
+STATIC
+VOID
+FindElfGOTSectionFromGOTEntryElfRva (
+ Elf64_Addr GOTEntryElfRva
+ )
+{
+ UINT32 i;
+ if (mGOTShdr != NULL) {
+ if (GOTEntryElfRva >= mGOTShdr->sh_addr &&
+ GOTEntryElfRva < mGOTShdr->sh_addr + mGOTShdr->sh_size)
+ return;
+ Error (NULL, 0, 3000, "Unsupported", "FindElfGOTSectionFromGOTEntryElfRva: GOT entries found in multiple sections.");
+ exit(EXIT_FAILURE);
+ }
+ for (i = 0; i < mEhdr->e_shnum; i++) {
+ Elf_Shdr *shdr = GetShdrByIndex(i);
+ if (GOTEntryElfRva >= shdr->sh_addr &&
+ GOTEntryElfRva < shdr->sh_addr + shdr->sh_size) {
+ mGOTShdr = shdr;
+ mGOTShindex = i;
+ return;
+ }
+ }
+ Error (NULL, 0, 3000, "Invalid", "FindElfGOTSectionFromGOTEntryElfRva: ElfRva 0x%016LX for GOT entry not found in any section.", GOTEntryElfRva);
+ exit(EXIT_FAILURE);
+}
+
+//
+// Stores locations of GOT entries in COFF image.
+// Returns TRUE if GOT entry is new.
+// Simple implementation as number of GOT
+// entries is expected to be low.
+//
+
+STATIC
+BOOLEAN
+AccumulateCoffGOTEntries (
+ UINT32 GOTCoffEntry
+ )
+{
+ UINT32 i;
+ if (mGOTCoffEntries != NULL) {
+ for (i = 0; i < mGOTNumCoffEntries; i++)
+ if (mGOTCoffEntries[i] == GOTCoffEntry)
+ return FALSE;
+ }
+ if (mGOTCoffEntries == NULL) {
+ mGOTCoffEntries = (UINT32*)malloc(5 * sizeof *mGOTCoffEntries);
+ if (mGOTCoffEntries == NULL) {
+ Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
+ }
+ assert (mGOTCoffEntries != NULL);
+ mGOTMaxCoffEntries = 5;
+ mGOTNumCoffEntries = 0;
+ } else if (mGOTNumCoffEntries == mGOTMaxCoffEntries) {
+ mGOTCoffEntries = (UINT32*)realloc(mGOTCoffEntries, 2 * mGOTMaxCoffEntries * sizeof *mGOTCoffEntries);
+ if (mGOTCoffEntries == NULL) {
+ Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
+ }
+ assert (mGOTCoffEntries != NULL);
+ mGOTMaxCoffEntries += mGOTMaxCoffEntries;
+ }
+ mGOTCoffEntries[mGOTNumCoffEntries++] = GOTCoffEntry;
+ return TRUE;
+}
+
+STATIC
+int
+__comparator (
+ const void* lhs,
+ const void* rhs
+ )
+{
+ if (*(const UINT32*)lhs < *(const UINT32*)rhs)
+ return -1;
+ return *(const UINT32*)lhs > *(const UINT32*)rhs;
+}
+
+STATIC
+VOID
+EmitGOTRelocations (
+ VOID
+ )
+{
+ UINT32 i;
+ if (mGOTCoffEntries == NULL)
+ return;
+ qsort(
+ mGOTCoffEntries,
+ mGOTNumCoffEntries,
+ sizeof *mGOTCoffEntries,
+ __comparator);
+ for (i = 0; i < mGOTNumCoffEntries; i++) {
+ VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X", mGOTCoffEntries[i]);
+ CoffAddFixup(
+ mGOTCoffEntries[i],
+ EFI_IMAGE_REL_BASED_DIR64);
+ }
+ free(mGOTCoffEntries);
+ mGOTCoffEntries = NULL;
+ mGOTMaxCoffEntries = 0;
+ mGOTNumCoffEntries = 0;
+}
+
//
// Elf functions interface implementation
//
@@ -698,7 +818,7 @@ WriteSections64 (
// section that applies to the entire binary, and which will have its section
// index set to #0 (which is a NULL section with the SHF_ALLOC bit cleared).
//
- // In the absence of GOT based relocations (which we currently don't support),
+ // In the absence of GOT based relocations,
// this RELA section will contain redundant R_xxx_RELATIVE relocations, one
// for every R_xxx_xx64 relocation appearing in the per-section RELA sections.
// (i.e., .rela.text and .rela.data)
@@ -780,6 +900,7 @@ WriteSections64 (
// Determine how to handle each relocation type based on the machine type.
//
if (mEhdr->e_machine == EM_X86_64) {
+ Elf64_Addr GOTEntryRva;
switch (ELF_R_TYPE(Rel->r_info)) {
case R_X86_64_NONE:
break;
@@ -834,6 +955,32 @@ WriteSections64 (
- (SecOffset - SecShdr->sh_addr));
VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
break;
+ case R_X86_64_GOTPCREL:
+ case R_X86_64_GOTPCRELX:
+ case R_X86_64_REX_GOTPCRELX:
+ VerboseMsg ("R_X86_64_GOTPCREL family");
+ VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
+ (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
+ *(UINT32 *)Targ);
+ GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32 *)Targ;
+ FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
+ *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
+ + (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
+ - (SecOffset - SecShdr->sh_addr));
+ VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
+ GOTEntryRva += (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr); // ELF Rva -> COFF Rva
+ if (AccumulateCoffGOTEntries((UINT32)GOTEntryRva)) {
+ //
+ // Relocate GOT entry if it's the first time we run into it
+ //
+ Targ = mCoffFile + GOTEntryRva;
+ VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX",
+ (UINT32)GOTEntryRva,
+ *(UINT64 *)Targ);
+ *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx];
+ VerboseMsg ("Relocation: 0x%016LX", *(UINT64*)Targ);
+ }
+ break;
default:
Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64 relocation 0x%x.", mInImageName, (unsigned) ELF_R_TYPE(Rel->r_info));
}
@@ -972,6 +1119,9 @@ WriteRelocations64 (
case R_X86_64_NONE:
case R_X86_64_PC32:
case R_X86_64_PLT32:
+ case R_X86_64_GOTPCREL:
+ case R_X86_64_GOTPCRELX:
+ case R_X86_64_REX_GOTPCRELX:
break;
case R_X86_64_64:
VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
@@ -1040,10 +1190,24 @@ WriteRelocations64 (
Error (NULL, 0, 3000, "Not Supported", "This tool does not support relocations for ELF with e_machine %u (processor type).", (unsigned) mEhdr->e_machine);
}
}
+ if (mEhdr->e_machine == EM_X86_64 && RelShdr->sh_info == mGOTShindex) {
+ //
+ // Tack relocations for GOT entries after other relocations for
+ // the section the GOT is in, as it's usually found at the end
+ // of the section.
+ //
+ EmitGOTRelocations();
+ }
}
}
}
+ if (mEhdr->e_machine == EM_X86_64) {
+ //
+ // Just in case GOT is in a section with no other relocations
+ //
+ EmitGOTRelocations();
+ }
//
// Pad by adding empty entries.
//
diff --git a/BaseTools/Source/C/GenFw/elf_common.h b/BaseTools/Source/C/GenFw/elf_common.h
index 766d0e42..50b4e1f2 100644
--- a/BaseTools/Source/C/GenFw/elf_common.h
+++ b/BaseTools/Source/C/GenFw/elf_common.h
@@ -544,6 +544,12 @@ typedef struct {
#define R_386_TLS_DTPMOD32 35 /* GOT entry containing TLS index */
#define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS offset */
#define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS offset */
+#define R_386_SIZE32 38 /* 32-bit symbol size */
+#define R_386_TLS_GOTDESC 39 /* GOT offset for TLS descriptor. */
+#define R_386_TLS_DESC_CALL 40 /* Marker of call through TLS descriptor for relaxation. */
+#define R_386_TLS_DESC 41 /* TLS descriptor containing pointer to code and to argument, returning the TLS offset for the symbol. */
+#define R_386_IRELATIVE 42 /* Adjust indirectly by program base */
+#define R_386_GOT32X 43 /* Load from 32 bit GOT entry, relaxable. */
/* Null relocation */
#define R_AARCH64_NONE 256 /* No relocation */
@@ -1052,6 +1058,23 @@ typedef struct {
#define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
#define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE GOT entry */
#define R_X86_64_TPOFF32 23 /* Offset in static TLS block */
+#define R_X86_64_PC64 24 /* PC relative 64 bit */
+#define R_X86_64_GOTOFF64 25 /* 64 bit offset to GOT */
+#define R_X86_64_GOTPC32 26 /* 32 bit signed pc relative offset to GOT */
+#define R_X86_64_GOT64 27 /* 64-bit GOT entry offset */
+#define R_X86_64_GOTPCREL64 28 /* 64-bit PC relative offset to GOT entry */
+#define R_X86_64_GOTPC64 29 /* 64-bit PC relative offset to GOT */
+#define R_X86_64_GOTPLT64 30 /* like GOT64, says PLT entry needed */
+#define R_X86_64_PLTOFF64 31 /* 64-bit GOT relative offset to PLT entry */
+#define R_X86_64_SIZE32 32 /* Size of symbol plus 32-bit addend */
+#define R_X86_64_SIZE64 33 /* Size of symbol plus 64-bit addend */
+#define R_X86_64_GOTPC32_TLSDESC 34 /* GOT offset for TLS descriptor. */
+#define R_X86_64_TLSDESC_CALL 35 /* Marker for call through TLS descriptor. */
+#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
+#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by program base */
+#define R_X86_64_RELATIVE64 38 /* 64-bit adjust by program base */
+#define R_X86_64_GOTPCRELX 41 /* Load from 32 bit signed pc relative offset to GOT entry without REX prefix, relaxable. */
+#define R_X86_64_REX_GOTPCRELX 42 /* Load from 32 bit signed pc relative offset to GOT entry with REX prefix, relaxable. */
#endif /* !_SYS_ELF_COMMON_H_ */
--
2.17.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
2018-06-06 18:01 ` [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw Zenith432
@ 2018-06-07 1:32 ` Gao, Liming
2018-06-07 2:15 ` Shi, Steven
0 siblings, 1 reply; 9+ messages in thread
From: Gao, Liming @ 2018-06-07 1:32 UTC (permalink / raw)
To: Zenith432, edk2-devel@lists.01.org
What's purpose to support GOTPCREL in GenFw? Could you introduce your usage model?
> -----Original Message-----
> From: Zenith432 [mailto:zenith432@users.sourceforge.net]
> Sent: Thursday, June 7, 2018 2:01 AM
> To: edk2-devel@lists.01.org
> Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong <yonghong.zhu@intel.com>; Gao, Liming <liming.gao@intel.com>
> Subject: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
>
> Adds support for the following X64 ELF relocations to GenFw
> R_X86_64_GOTPCREL
> R_X86_64_GOTPCRELX
> R_X86_64_REX_GOTPCRELX
>
> CC: Shi Steven <steven.shi@intel.com>
> CC: Yonghong Zhu <yonghong.zhu@intel.com>
> CC: Liming Gao <liming.gao@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
> ---
> BaseTools/Source/C/GenFw/Elf64Convert.c | 166 +++++++++++++++++++++++-
> BaseTools/Source/C/GenFw/elf_common.h | 23 ++++
> 2 files changed, 188 insertions(+), 1 deletion(-)
>
> diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
> index c39bdff0..d2f9bb46 100644
> --- a/BaseTools/Source/C/GenFw/Elf64Convert.c
> +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
> @@ -94,6 +94,15 @@ STATIC Elf_Ehdr *mEhdr;
> STATIC Elf_Shdr *mShdrBase;
> STATIC Elf_Phdr *mPhdrBase;
>
> +//
> +// GOT information
> +//
> +STATIC Elf_Shdr *mGOTShdr = NULL;
> +STATIC UINT32 mGOTShindex = 0;
> +STATIC UINT32 *mGOTCoffEntries = NULL;
> +STATIC UINT32 mGOTMaxCoffEntries = 0;
> +STATIC UINT32 mGOTNumCoffEntries = 0;
> +
> //
> // Coff information
> //
> @@ -322,6 +331,117 @@ GetSymName (
> return StrtabContents + Sym->st_name;
> }
>
> +//
> +// Find the ELF section hosting the GOT from an ELF Rva
> +// of a single GOT entry. Normally, GOT is placed in
> +// ELF .text section, so assume once we find in which
> +// section the GOT is, all GOT entries are there, and
> +// just verify this.
> +//
> +STATIC
> +VOID
> +FindElfGOTSectionFromGOTEntryElfRva (
> + Elf64_Addr GOTEntryElfRva
> + )
> +{
> + UINT32 i;
> + if (mGOTShdr != NULL) {
> + if (GOTEntryElfRva >= mGOTShdr->sh_addr &&
> + GOTEntryElfRva < mGOTShdr->sh_addr + mGOTShdr->sh_size)
> + return;
> + Error (NULL, 0, 3000, "Unsupported", "FindElfGOTSectionFromGOTEntryElfRva: GOT entries found in multiple sections.");
> + exit(EXIT_FAILURE);
> + }
> + for (i = 0; i < mEhdr->e_shnum; i++) {
> + Elf_Shdr *shdr = GetShdrByIndex(i);
> + if (GOTEntryElfRva >= shdr->sh_addr &&
> + GOTEntryElfRva < shdr->sh_addr + shdr->sh_size) {
> + mGOTShdr = shdr;
> + mGOTShindex = i;
> + return;
> + }
> + }
> + Error (NULL, 0, 3000, "Invalid", "FindElfGOTSectionFromGOTEntryElfRva: ElfRva 0x%016LX for GOT entry not found in any section.",
> GOTEntryElfRva);
> + exit(EXIT_FAILURE);
> +}
> +
> +//
> +// Stores locations of GOT entries in COFF image.
> +// Returns TRUE if GOT entry is new.
> +// Simple implementation as number of GOT
> +// entries is expected to be low.
> +//
> +
> +STATIC
> +BOOLEAN
> +AccumulateCoffGOTEntries (
> + UINT32 GOTCoffEntry
> + )
> +{
> + UINT32 i;
> + if (mGOTCoffEntries != NULL) {
> + for (i = 0; i < mGOTNumCoffEntries; i++)
> + if (mGOTCoffEntries[i] == GOTCoffEntry)
> + return FALSE;
> + }
> + if (mGOTCoffEntries == NULL) {
> + mGOTCoffEntries = (UINT32*)malloc(5 * sizeof *mGOTCoffEntries);
> + if (mGOTCoffEntries == NULL) {
> + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> + }
> + assert (mGOTCoffEntries != NULL);
> + mGOTMaxCoffEntries = 5;
> + mGOTNumCoffEntries = 0;
> + } else if (mGOTNumCoffEntries == mGOTMaxCoffEntries) {
> + mGOTCoffEntries = (UINT32*)realloc(mGOTCoffEntries, 2 * mGOTMaxCoffEntries * sizeof *mGOTCoffEntries);
> + if (mGOTCoffEntries == NULL) {
> + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> + }
> + assert (mGOTCoffEntries != NULL);
> + mGOTMaxCoffEntries += mGOTMaxCoffEntries;
> + }
> + mGOTCoffEntries[mGOTNumCoffEntries++] = GOTCoffEntry;
> + return TRUE;
> +}
> +
> +STATIC
> +int
> +__comparator (
> + const void* lhs,
> + const void* rhs
> + )
> +{
> + if (*(const UINT32*)lhs < *(const UINT32*)rhs)
> + return -1;
> + return *(const UINT32*)lhs > *(const UINT32*)rhs;
> +}
> +
> +STATIC
> +VOID
> +EmitGOTRelocations (
> + VOID
> + )
> +{
> + UINT32 i;
> + if (mGOTCoffEntries == NULL)
> + return;
> + qsort(
> + mGOTCoffEntries,
> + mGOTNumCoffEntries,
> + sizeof *mGOTCoffEntries,
> + __comparator);
> + for (i = 0; i < mGOTNumCoffEntries; i++) {
> + VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X", mGOTCoffEntries[i]);
> + CoffAddFixup(
> + mGOTCoffEntries[i],
> + EFI_IMAGE_REL_BASED_DIR64);
> + }
> + free(mGOTCoffEntries);
> + mGOTCoffEntries = NULL;
> + mGOTMaxCoffEntries = 0;
> + mGOTNumCoffEntries = 0;
> +}
> +
> //
> // Elf functions interface implementation
> //
> @@ -698,7 +818,7 @@ WriteSections64 (
> // section that applies to the entire binary, and which will have its section
> // index set to #0 (which is a NULL section with the SHF_ALLOC bit cleared).
> //
> - // In the absence of GOT based relocations (which we currently don't support),
> + // In the absence of GOT based relocations,
> // this RELA section will contain redundant R_xxx_RELATIVE relocations, one
> // for every R_xxx_xx64 relocation appearing in the per-section RELA sections.
> // (i.e., .rela.text and .rela.data)
> @@ -780,6 +900,7 @@ WriteSections64 (
> // Determine how to handle each relocation type based on the machine type.
> //
> if (mEhdr->e_machine == EM_X86_64) {
> + Elf64_Addr GOTEntryRva;
> switch (ELF_R_TYPE(Rel->r_info)) {
> case R_X86_64_NONE:
> break;
> @@ -834,6 +955,32 @@ WriteSections64 (
> - (SecOffset - SecShdr->sh_addr));
> VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> break;
> + case R_X86_64_GOTPCREL:
> + case R_X86_64_GOTPCRELX:
> + case R_X86_64_REX_GOTPCRELX:
> + VerboseMsg ("R_X86_64_GOTPCREL family");
> + VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
> + (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
> + *(UINT32 *)Targ);
> + GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32 *)Targ;
> + FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
> + *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
> + + (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
> + - (SecOffset - SecShdr->sh_addr));
> + VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> + GOTEntryRva += (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr); // ELF Rva -> COFF Rva
> + if (AccumulateCoffGOTEntries((UINT32)GOTEntryRva)) {
> + //
> + // Relocate GOT entry if it's the first time we run into it
> + //
> + Targ = mCoffFile + GOTEntryRva;
> + VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX",
> + (UINT32)GOTEntryRva,
> + *(UINT64 *)Targ);
> + *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx];
> + VerboseMsg ("Relocation: 0x%016LX", *(UINT64*)Targ);
> + }
> + break;
> default:
> Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64 relocation 0x%x.", mInImageName, (unsigned)
> ELF_R_TYPE(Rel->r_info));
> }
> @@ -972,6 +1119,9 @@ WriteRelocations64 (
> case R_X86_64_NONE:
> case R_X86_64_PC32:
> case R_X86_64_PLT32:
> + case R_X86_64_GOTPCREL:
> + case R_X86_64_GOTPCRELX:
> + case R_X86_64_REX_GOTPCRELX:
> break;
> case R_X86_64_64:
> VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> @@ -1040,10 +1190,24 @@ WriteRelocations64 (
> Error (NULL, 0, 3000, "Not Supported", "This tool does not support relocations for ELF with e_machine %u (processor
> type).", (unsigned) mEhdr->e_machine);
> }
> }
> + if (mEhdr->e_machine == EM_X86_64 && RelShdr->sh_info == mGOTShindex) {
> + //
> + // Tack relocations for GOT entries after other relocations for
> + // the section the GOT is in, as it's usually found at the end
> + // of the section.
> + //
> + EmitGOTRelocations();
> + }
> }
> }
> }
>
> + if (mEhdr->e_machine == EM_X86_64) {
> + //
> + // Just in case GOT is in a section with no other relocations
> + //
> + EmitGOTRelocations();
> + }
> //
> // Pad by adding empty entries.
> //
> diff --git a/BaseTools/Source/C/GenFw/elf_common.h b/BaseTools/Source/C/GenFw/elf_common.h
> index 766d0e42..50b4e1f2 100644
> --- a/BaseTools/Source/C/GenFw/elf_common.h
> +++ b/BaseTools/Source/C/GenFw/elf_common.h
> @@ -544,6 +544,12 @@ typedef struct {
> #define R_386_TLS_DTPMOD32 35 /* GOT entry containing TLS index */
> #define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS offset */
> #define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS offset */
> +#define R_386_SIZE32 38 /* 32-bit symbol size */
> +#define R_386_TLS_GOTDESC 39 /* GOT offset for TLS descriptor. */
> +#define R_386_TLS_DESC_CALL 40 /* Marker of call through TLS descriptor for relaxation. */
> +#define R_386_TLS_DESC 41 /* TLS descriptor containing pointer to code and to argument, returning the TLS offset for the
> symbol. */
> +#define R_386_IRELATIVE 42 /* Adjust indirectly by program base */
> +#define R_386_GOT32X 43 /* Load from 32 bit GOT entry, relaxable. */
>
> /* Null relocation */
> #define R_AARCH64_NONE 256 /* No relocation */
> @@ -1052,6 +1058,23 @@ typedef struct {
> #define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
> #define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE GOT entry */
> #define R_X86_64_TPOFF32 23 /* Offset in static TLS block */
> +#define R_X86_64_PC64 24 /* PC relative 64 bit */
> +#define R_X86_64_GOTOFF64 25 /* 64 bit offset to GOT */
> +#define R_X86_64_GOTPC32 26 /* 32 bit signed pc relative offset to GOT */
> +#define R_X86_64_GOT64 27 /* 64-bit GOT entry offset */
> +#define R_X86_64_GOTPCREL64 28 /* 64-bit PC relative offset to GOT entry */
> +#define R_X86_64_GOTPC64 29 /* 64-bit PC relative offset to GOT */
> +#define R_X86_64_GOTPLT64 30 /* like GOT64, says PLT entry needed */
> +#define R_X86_64_PLTOFF64 31 /* 64-bit GOT relative offset to PLT entry */
> +#define R_X86_64_SIZE32 32 /* Size of symbol plus 32-bit addend */
> +#define R_X86_64_SIZE64 33 /* Size of symbol plus 64-bit addend */
> +#define R_X86_64_GOTPC32_TLSDESC 34 /* GOT offset for TLS descriptor. */
> +#define R_X86_64_TLSDESC_CALL 35 /* Marker for call through TLS descriptor. */
> +#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
> +#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by program base */
> +#define R_X86_64_RELATIVE64 38 /* 64-bit adjust by program base */
> +#define R_X86_64_GOTPCRELX 41 /* Load from 32 bit signed pc relative offset to GOT entry without REX prefix, relaxable. */
> +#define R_X86_64_REX_GOTPCRELX 42 /* Load from 32 bit signed pc relative offset to GOT entry with REX prefix, relaxable. */
>
>
> #endif /* !_SYS_ELF_COMMON_H_ */
> --
> 2.17.1
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
2018-06-07 1:32 ` Gao, Liming
@ 2018-06-07 2:15 ` Shi, Steven
2018-06-07 2:17 ` Shi, Steven
0 siblings, 1 reply; 9+ messages in thread
From: Shi, Steven @ 2018-06-07 2:15 UTC (permalink / raw)
To: Gao, Liming, Zenith432, edk2-devel@lists.01.org
Yes. If we disable the '#pragma GCC visibility push (hidden)' in ProcessorBind.h, the GOTPCREL support is mandatory. 3rd party module build might need it. It's more complete to add GOTPCREL support.
The hidden #pragma can hide all ELF symbols' visibility, including 'extern' functions, which is to let Linux compilers aware that we don’t need loading dynamic link library in Uefi runing, please not emit the GOTPCREL based relocations in the obj file, and we will ensure the linker can get all extern functions statically solved. The reason of not emitting GOTPCREL based relocations is because it is hard to convert the GOTPCREL based relocations in ELF binary to PE/COFF related relocations, and our current GenFw has not supported them. I'm glade if we can add the GOTPCREL support in GenFW to totally solve this problem.
Steven Shi
Intel\SSG\STO\UEFI Firmware
Tel: +86 021-61166522
iNet: 821-6522
> -----Original Message-----
> From: Gao, Liming
> Sent: Thursday, June 7, 2018 9:32 AM
> To: Zenith432 <zenith432@users.sourceforge.net>; edk2-devel@lists.01.org
> Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> <yonghong.zhu@intel.com>
> Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> GenFw
>
> What's purpose to support GOTPCREL in GenFw? Could you introduce your
> usage model?
>
> > -----Original Message-----
> > From: Zenith432 [mailto:zenith432@users.sourceforge.net]
> > Sent: Thursday, June 7, 2018 2:01 AM
> > To: edk2-devel@lists.01.org
> > Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> <yonghong.zhu@intel.com>; Gao, Liming <liming.gao@intel.com>
> > Subject: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
> >
> > Adds support for the following X64 ELF relocations to GenFw
> > R_X86_64_GOTPCREL
> > R_X86_64_GOTPCRELX
> > R_X86_64_REX_GOTPCRELX
> >
> > CC: Shi Steven <steven.shi@intel.com>
> > CC: Yonghong Zhu <yonghong.zhu@intel.com>
> > CC: Liming Gao <liming.gao@intel.com>
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
> > ---
> > BaseTools/Source/C/GenFw/Elf64Convert.c | 166
> +++++++++++++++++++++++-
> > BaseTools/Source/C/GenFw/elf_common.h | 23 ++++
> > 2 files changed, 188 insertions(+), 1 deletion(-)
> >
> > diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c
> b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > index c39bdff0..d2f9bb46 100644
> > --- a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > @@ -94,6 +94,15 @@ STATIC Elf_Ehdr *mEhdr;
> > STATIC Elf_Shdr *mShdrBase;
> > STATIC Elf_Phdr *mPhdrBase;
> >
> > +//
> > +// GOT information
> > +//
> > +STATIC Elf_Shdr *mGOTShdr = NULL;
> > +STATIC UINT32 mGOTShindex = 0;
> > +STATIC UINT32 *mGOTCoffEntries = NULL;
> > +STATIC UINT32 mGOTMaxCoffEntries = 0;
> > +STATIC UINT32 mGOTNumCoffEntries = 0;
> > +
> > //
> > // Coff information
> > //
> > @@ -322,6 +331,117 @@ GetSymName (
> > return StrtabContents + Sym->st_name;
> > }
> >
> > +//
> > +// Find the ELF section hosting the GOT from an ELF Rva
> > +// of a single GOT entry. Normally, GOT is placed in
> > +// ELF .text section, so assume once we find in which
> > +// section the GOT is, all GOT entries are there, and
> > +// just verify this.
> > +//
> > +STATIC
> > +VOID
> > +FindElfGOTSectionFromGOTEntryElfRva (
> > + Elf64_Addr GOTEntryElfRva
> > + )
> > +{
> > + UINT32 i;
> > + if (mGOTShdr != NULL) {
> > + if (GOTEntryElfRva >= mGOTShdr->sh_addr &&
> > + GOTEntryElfRva < mGOTShdr->sh_addr + mGOTShdr->sh_size)
> > + return;
> > + Error (NULL, 0, 3000, "Unsupported",
> "FindElfGOTSectionFromGOTEntryElfRva: GOT entries found in multiple
> sections.");
> > + exit(EXIT_FAILURE);
> > + }
> > + for (i = 0; i < mEhdr->e_shnum; i++) {
> > + Elf_Shdr *shdr = GetShdrByIndex(i);
> > + if (GOTEntryElfRva >= shdr->sh_addr &&
> > + GOTEntryElfRva < shdr->sh_addr + shdr->sh_size) {
> > + mGOTShdr = shdr;
> > + mGOTShindex = i;
> > + return;
> > + }
> > + }
> > + Error (NULL, 0, 3000, "Invalid", "FindElfGOTSectionFromGOTEntryElfRva:
> ElfRva 0x%016LX for GOT entry not found in any section.",
> > GOTEntryElfRva);
> > + exit(EXIT_FAILURE);
> > +}
> > +
> > +//
> > +// Stores locations of GOT entries in COFF image.
> > +// Returns TRUE if GOT entry is new.
> > +// Simple implementation as number of GOT
> > +// entries is expected to be low.
> > +//
> > +
> > +STATIC
> > +BOOLEAN
> > +AccumulateCoffGOTEntries (
> > + UINT32 GOTCoffEntry
> > + )
> > +{
> > + UINT32 i;
> > + if (mGOTCoffEntries != NULL) {
> > + for (i = 0; i < mGOTNumCoffEntries; i++)
> > + if (mGOTCoffEntries[i] == GOTCoffEntry)
> > + return FALSE;
> > + }
> > + if (mGOTCoffEntries == NULL) {
> > + mGOTCoffEntries = (UINT32*)malloc(5 * sizeof *mGOTCoffEntries);
> > + if (mGOTCoffEntries == NULL) {
> > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > + }
> > + assert (mGOTCoffEntries != NULL);
> > + mGOTMaxCoffEntries = 5;
> > + mGOTNumCoffEntries = 0;
> > + } else if (mGOTNumCoffEntries == mGOTMaxCoffEntries) {
> > + mGOTCoffEntries = (UINT32*)realloc(mGOTCoffEntries, 2 *
> mGOTMaxCoffEntries * sizeof *mGOTCoffEntries);
> > + if (mGOTCoffEntries == NULL) {
> > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > + }
> > + assert (mGOTCoffEntries != NULL);
> > + mGOTMaxCoffEntries += mGOTMaxCoffEntries;
> > + }
> > + mGOTCoffEntries[mGOTNumCoffEntries++] = GOTCoffEntry;
> > + return TRUE;
> > +}
> > +
> > +STATIC
> > +int
> > +__comparator (
> > + const void* lhs,
> > + const void* rhs
> > + )
> > +{
> > + if (*(const UINT32*)lhs < *(const UINT32*)rhs)
> > + return -1;
> > + return *(const UINT32*)lhs > *(const UINT32*)rhs;
> > +}
> > +
> > +STATIC
> > +VOID
> > +EmitGOTRelocations (
> > + VOID
> > + )
> > +{
> > + UINT32 i;
> > + if (mGOTCoffEntries == NULL)
> > + return;
> > + qsort(
> > + mGOTCoffEntries,
> > + mGOTNumCoffEntries,
> > + sizeof *mGOTCoffEntries,
> > + __comparator);
> > + for (i = 0; i < mGOTNumCoffEntries; i++) {
> > + VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> mGOTCoffEntries[i]);
> > + CoffAddFixup(
> > + mGOTCoffEntries[i],
> > + EFI_IMAGE_REL_BASED_DIR64);
> > + }
> > + free(mGOTCoffEntries);
> > + mGOTCoffEntries = NULL;
> > + mGOTMaxCoffEntries = 0;
> > + mGOTNumCoffEntries = 0;
> > +}
> > +
> > //
> > // Elf functions interface implementation
> > //
> > @@ -698,7 +818,7 @@ WriteSections64 (
> > // section that applies to the entire binary, and which will have its
> section
> > // index set to #0 (which is a NULL section with the SHF_ALLOC bit
> cleared).
> > //
> > - // In the absence of GOT based relocations (which we currently don't
> support),
> > + // In the absence of GOT based relocations,
> > // this RELA section will contain redundant R_xxx_RELATIVE relocations,
> one
> > // for every R_xxx_xx64 relocation appearing in the per-section RELA
> sections.
> > // (i.e., .rela.text and .rela.data)
> > @@ -780,6 +900,7 @@ WriteSections64 (
> > // Determine how to handle each relocation type based on the
> machine type.
> > //
> > if (mEhdr->e_machine == EM_X86_64) {
> > + Elf64_Addr GOTEntryRva;
> > switch (ELF_R_TYPE(Rel->r_info)) {
> > case R_X86_64_NONE:
> > break;
> > @@ -834,6 +955,32 @@ WriteSections64 (
> > - (SecOffset - SecShdr->sh_addr));
> > VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > break;
> > + case R_X86_64_GOTPCREL:
> > + case R_X86_64_GOTPCRELX:
> > + case R_X86_64_REX_GOTPCRELX:
> > + VerboseMsg ("R_X86_64_GOTPCREL family");
> > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
> > + (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
> > + *(UINT32 *)Targ);
> > + GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32 *)Targ;
> > + FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
> > + *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
> > + + (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
> > + - (SecOffset - SecShdr->sh_addr));
> > + VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > + GOTEntryRva += (mCoffSectionsOffset[mGOTShindex] - mGOTShdr-
> >sh_addr); // ELF Rva -> COFF Rva
> > + if (AccumulateCoffGOTEntries((UINT32)GOTEntryRva)) {
> > + //
> > + // Relocate GOT entry if it's the first time we run into it
> > + //
> > + Targ = mCoffFile + GOTEntryRva;
> > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX",
> > + (UINT32)GOTEntryRva,
> > + *(UINT64 *)Targ);
> > + *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr +
> mCoffSectionsOffset[Sym->st_shndx];
> > + VerboseMsg ("Relocation: 0x%016LX", *(UINT64*)Targ);
> > + }
> > + break;
> > default:
> > Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64
> relocation 0x%x.", mInImageName, (unsigned)
> > ELF_R_TYPE(Rel->r_info));
> > }
> > @@ -972,6 +1119,9 @@ WriteRelocations64 (
> > case R_X86_64_NONE:
> > case R_X86_64_PC32:
> > case R_X86_64_PLT32:
> > + case R_X86_64_GOTPCREL:
> > + case R_X86_64_GOTPCRELX:
> > + case R_X86_64_REX_GOTPCRELX:
> > break;
> > case R_X86_64_64:
> > VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> > @@ -1040,10 +1190,24 @@ WriteRelocations64 (
> > Error (NULL, 0, 3000, "Not Supported", "This tool does not support
> relocations for ELF with e_machine %u (processor
> > type).", (unsigned) mEhdr->e_machine);
> > }
> > }
> > + if (mEhdr->e_machine == EM_X86_64 && RelShdr->sh_info ==
> mGOTShindex) {
> > + //
> > + // Tack relocations for GOT entries after other relocations for
> > + // the section the GOT is in, as it's usually found at the end
> > + // of the section.
> > + //
> > + EmitGOTRelocations();
> > + }
> > }
> > }
> > }
> >
> > + if (mEhdr->e_machine == EM_X86_64) {
> > + //
> > + // Just in case GOT is in a section with no other relocations
> > + //
> > + EmitGOTRelocations();
> > + }
> > //
> > // Pad by adding empty entries.
> > //
> > diff --git a/BaseTools/Source/C/GenFw/elf_common.h
> b/BaseTools/Source/C/GenFw/elf_common.h
> > index 766d0e42..50b4e1f2 100644
> > --- a/BaseTools/Source/C/GenFw/elf_common.h
> > +++ b/BaseTools/Source/C/GenFw/elf_common.h
> > @@ -544,6 +544,12 @@ typedef struct {
> > #define R_386_TLS_DTPMOD32 35 /* GOT entry
> containing TLS index */
> > #define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS
> offset */
> > #define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS
> offset */
> > +#define R_386_SIZE32 38 /* 32-bit symbol size */
> > +#define R_386_TLS_GOTDESC 39 /* GOT offset for TLS
> descriptor. */
> > +#define R_386_TLS_DESC_CALL 40 /* Marker of call through TLS
> descriptor for relaxation. */
> > +#define R_386_TLS_DESC 41 /* TLS descriptor
> containing pointer to code and to argument, returning the TLS offset for the
> > symbol. */
> > +#define R_386_IRELATIVE 42 /* Adjust indirectly by
> program base */
> > +#define R_386_GOT32X 43 /* Load from 32 bit GOT
> entry, relaxable. */
> >
> > /* Null relocation */
> > #define R_AARCH64_NONE 256 /*
> No relocation */
> > @@ -1052,6 +1058,23 @@ typedef struct {
> > #define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
> > #define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE
> GOT entry */
> > #define R_X86_64_TPOFF32 23 /* Offset in static TLS block
> */
> > +#define R_X86_64_PC64 24 /* PC relative 64 bit
> */
> > +#define R_X86_64_GOTOFF64 25 /* 64 bit offset to GOT */
> > +#define R_X86_64_GOTPC32 26 /* 32 bit signed pc relative
> offset to GOT */
> > +#define R_X86_64_GOT64 27 /* 64-bit GOT entry
> offset */
> > +#define R_X86_64_GOTPCREL64 28 /* 64-bit PC relative
> offset to GOT entry */
> > +#define R_X86_64_GOTPC64 29 /* 64-bit PC relative offset to
> GOT */
> > +#define R_X86_64_GOTPLT64 30 /* like GOT64, says PLT entry
> needed */
> > +#define R_X86_64_PLTOFF64 31 /* 64-bit GOT relative offset
> to PLT entry */
> > +#define R_X86_64_SIZE32 32 /* Size of symbol plus
> 32-bit addend */
> > +#define R_X86_64_SIZE64 33 /* Size of symbol plus
> 64-bit addend */
> > +#define R_X86_64_GOTPC32_TLSDESC 34 /* GOT offset for TLS
> descriptor. */
> > +#define R_X86_64_TLSDESC_CALL 35 /* Marker for call
> through TLS descriptor. */
> > +#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
> > +#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by
> program base */
> > +#define R_X86_64_RELATIVE64 38 /* 64-bit adjust by program
> base */
> > +#define R_X86_64_GOTPCRELX 41 /* Load from 32 bit signed pc
> relative offset to GOT entry without REX prefix, relaxable. */
> > +#define R_X86_64_REX_GOTPCRELX 42 /* Load from 32 bit
> signed pc relative offset to GOT entry with REX prefix, relaxable. */
> >
> >
> > #endif /* !_SYS_ELF_COMMON_H_ */
> > --
> > 2.17.1
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
2018-06-07 2:15 ` Shi, Steven
@ 2018-06-07 2:17 ` Shi, Steven
2018-06-07 2:24 ` Shi, Steven
0 siblings, 1 reply; 9+ messages in thread
From: Shi, Steven @ 2018-06-07 2:17 UTC (permalink / raw)
To: Shi, Steven, Gao, Liming, Zenith432, edk2-devel@lists.01.org
Please see more details in https://bugzilla.tianocore.org/show_bug.cgi?id=970
Steven Shi
Intel\SSG\STO\UEFI Firmware
Tel: +86 021-61166522
iNet: 821-6522
> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Shi,
> Steven
> Sent: Thursday, June 7, 2018 10:16 AM
> To: Gao, Liming <liming.gao@intel.com>; Zenith432
> <zenith432@users.sourceforge.net>; edk2-devel@lists.01.org
> Subject: Re: [edk2] [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support
> to GenFw
>
> Yes. If we disable the '#pragma GCC visibility push (hidden)' in
> ProcessorBind.h, the GOTPCREL support is mandatory. 3rd party module
> build might need it. It's more complete to add GOTPCREL support.
>
> The hidden #pragma can hide all ELF symbols' visibility, including 'extern'
> functions, which is to let Linux compilers aware that we don’t need loading
> dynamic link library in Uefi runing, please not emit the GOTPCREL based
> relocations in the obj file, and we will ensure the linker can get all extern
> functions statically solved. The reason of not emitting GOTPCREL based
> relocations is because it is hard to convert the GOTPCREL based relocations
> in ELF binary to PE/COFF related relocations, and our current GenFw has not
> supported them. I'm glade if we can add the GOTPCREL support in GenFW to
> totally solve this problem.
>
> Steven Shi
> Intel\SSG\STO\UEFI Firmware
>
> Tel: +86 021-61166522
> iNet: 821-6522
>
> > -----Original Message-----
> > From: Gao, Liming
> > Sent: Thursday, June 7, 2018 9:32 AM
> > To: Zenith432 <zenith432@users.sourceforge.net>; edk2-
> devel@lists.01.org
> > Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> > <yonghong.zhu@intel.com>
> > Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> > GenFw
> >
> > What's purpose to support GOTPCREL in GenFw? Could you introduce your
> > usage model?
> >
> > > -----Original Message-----
> > > From: Zenith432 [mailto:zenith432@users.sourceforge.net]
> > > Sent: Thursday, June 7, 2018 2:01 AM
> > > To: edk2-devel@lists.01.org
> > > Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> > <yonghong.zhu@intel.com>; Gao, Liming <liming.gao@intel.com>
> > > Subject: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> GenFw
> > >
> > > Adds support for the following X64 ELF relocations to GenFw
> > > R_X86_64_GOTPCREL
> > > R_X86_64_GOTPCRELX
> > > R_X86_64_REX_GOTPCRELX
> > >
> > > CC: Shi Steven <steven.shi@intel.com>
> > > CC: Yonghong Zhu <yonghong.zhu@intel.com>
> > > CC: Liming Gao <liming.gao@intel.com>
> > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
> > > ---
> > > BaseTools/Source/C/GenFw/Elf64Convert.c | 166
> > +++++++++++++++++++++++-
> > > BaseTools/Source/C/GenFw/elf_common.h | 23 ++++
> > > 2 files changed, 188 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > index c39bdff0..d2f9bb46 100644
> > > --- a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > @@ -94,6 +94,15 @@ STATIC Elf_Ehdr *mEhdr;
> > > STATIC Elf_Shdr *mShdrBase;
> > > STATIC Elf_Phdr *mPhdrBase;
> > >
> > > +//
> > > +// GOT information
> > > +//
> > > +STATIC Elf_Shdr *mGOTShdr = NULL;
> > > +STATIC UINT32 mGOTShindex = 0;
> > > +STATIC UINT32 *mGOTCoffEntries = NULL;
> > > +STATIC UINT32 mGOTMaxCoffEntries = 0;
> > > +STATIC UINT32 mGOTNumCoffEntries = 0;
> > > +
> > > //
> > > // Coff information
> > > //
> > > @@ -322,6 +331,117 @@ GetSymName (
> > > return StrtabContents + Sym->st_name;
> > > }
> > >
> > > +//
> > > +// Find the ELF section hosting the GOT from an ELF Rva
> > > +// of a single GOT entry. Normally, GOT is placed in
> > > +// ELF .text section, so assume once we find in which
> > > +// section the GOT is, all GOT entries are there, and
> > > +// just verify this.
> > > +//
> > > +STATIC
> > > +VOID
> > > +FindElfGOTSectionFromGOTEntryElfRva (
> > > + Elf64_Addr GOTEntryElfRva
> > > + )
> > > +{
> > > + UINT32 i;
> > > + if (mGOTShdr != NULL) {
> > > + if (GOTEntryElfRva >= mGOTShdr->sh_addr &&
> > > + GOTEntryElfRva < mGOTShdr->sh_addr + mGOTShdr->sh_size)
> > > + return;
> > > + Error (NULL, 0, 3000, "Unsupported",
> > "FindElfGOTSectionFromGOTEntryElfRva: GOT entries found in multiple
> > sections.");
> > > + exit(EXIT_FAILURE);
> > > + }
> > > + for (i = 0; i < mEhdr->e_shnum; i++) {
> > > + Elf_Shdr *shdr = GetShdrByIndex(i);
> > > + if (GOTEntryElfRva >= shdr->sh_addr &&
> > > + GOTEntryElfRva < shdr->sh_addr + shdr->sh_size) {
> > > + mGOTShdr = shdr;
> > > + mGOTShindex = i;
> > > + return;
> > > + }
> > > + }
> > > + Error (NULL, 0, 3000, "Invalid",
> "FindElfGOTSectionFromGOTEntryElfRva:
> > ElfRva 0x%016LX for GOT entry not found in any section.",
> > > GOTEntryElfRva);
> > > + exit(EXIT_FAILURE);
> > > +}
> > > +
> > > +//
> > > +// Stores locations of GOT entries in COFF image.
> > > +// Returns TRUE if GOT entry is new.
> > > +// Simple implementation as number of GOT
> > > +// entries is expected to be low.
> > > +//
> > > +
> > > +STATIC
> > > +BOOLEAN
> > > +AccumulateCoffGOTEntries (
> > > + UINT32 GOTCoffEntry
> > > + )
> > > +{
> > > + UINT32 i;
> > > + if (mGOTCoffEntries != NULL) {
> > > + for (i = 0; i < mGOTNumCoffEntries; i++)
> > > + if (mGOTCoffEntries[i] == GOTCoffEntry)
> > > + return FALSE;
> > > + }
> > > + if (mGOTCoffEntries == NULL) {
> > > + mGOTCoffEntries = (UINT32*)malloc(5 * sizeof *mGOTCoffEntries);
> > > + if (mGOTCoffEntries == NULL) {
> > > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > > + }
> > > + assert (mGOTCoffEntries != NULL);
> > > + mGOTMaxCoffEntries = 5;
> > > + mGOTNumCoffEntries = 0;
> > > + } else if (mGOTNumCoffEntries == mGOTMaxCoffEntries) {
> > > + mGOTCoffEntries = (UINT32*)realloc(mGOTCoffEntries, 2 *
> > mGOTMaxCoffEntries * sizeof *mGOTCoffEntries);
> > > + if (mGOTCoffEntries == NULL) {
> > > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > > + }
> > > + assert (mGOTCoffEntries != NULL);
> > > + mGOTMaxCoffEntries += mGOTMaxCoffEntries;
> > > + }
> > > + mGOTCoffEntries[mGOTNumCoffEntries++] = GOTCoffEntry;
> > > + return TRUE;
> > > +}
> > > +
> > > +STATIC
> > > +int
> > > +__comparator (
> > > + const void* lhs,
> > > + const void* rhs
> > > + )
> > > +{
> > > + if (*(const UINT32*)lhs < *(const UINT32*)rhs)
> > > + return -1;
> > > + return *(const UINT32*)lhs > *(const UINT32*)rhs;
> > > +}
> > > +
> > > +STATIC
> > > +VOID
> > > +EmitGOTRelocations (
> > > + VOID
> > > + )
> > > +{
> > > + UINT32 i;
> > > + if (mGOTCoffEntries == NULL)
> > > + return;
> > > + qsort(
> > > + mGOTCoffEntries,
> > > + mGOTNumCoffEntries,
> > > + sizeof *mGOTCoffEntries,
> > > + __comparator);
> > > + for (i = 0; i < mGOTNumCoffEntries; i++) {
> > > + VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> > mGOTCoffEntries[i]);
> > > + CoffAddFixup(
> > > + mGOTCoffEntries[i],
> > > + EFI_IMAGE_REL_BASED_DIR64);
> > > + }
> > > + free(mGOTCoffEntries);
> > > + mGOTCoffEntries = NULL;
> > > + mGOTMaxCoffEntries = 0;
> > > + mGOTNumCoffEntries = 0;
> > > +}
> > > +
> > > //
> > > // Elf functions interface implementation
> > > //
> > > @@ -698,7 +818,7 @@ WriteSections64 (
> > > // section that applies to the entire binary, and which will have its
> > section
> > > // index set to #0 (which is a NULL section with the SHF_ALLOC bit
> > cleared).
> > > //
> > > - // In the absence of GOT based relocations (which we currently don't
> > support),
> > > + // In the absence of GOT based relocations,
> > > // this RELA section will contain redundant R_xxx_RELATIVE
> relocations,
> > one
> > > // for every R_xxx_xx64 relocation appearing in the per-section RELA
> > sections.
> > > // (i.e., .rela.text and .rela.data)
> > > @@ -780,6 +900,7 @@ WriteSections64 (
> > > // Determine how to handle each relocation type based on the
> > machine type.
> > > //
> > > if (mEhdr->e_machine == EM_X86_64) {
> > > + Elf64_Addr GOTEntryRva;
> > > switch (ELF_R_TYPE(Rel->r_info)) {
> > > case R_X86_64_NONE:
> > > break;
> > > @@ -834,6 +955,32 @@ WriteSections64 (
> > > - (SecOffset - SecShdr->sh_addr));
> > > VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > > break;
> > > + case R_X86_64_GOTPCREL:
> > > + case R_X86_64_GOTPCRELX:
> > > + case R_X86_64_REX_GOTPCRELX:
> > > + VerboseMsg ("R_X86_64_GOTPCREL family");
> > > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
> > > + (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
> > > + *(UINT32 *)Targ);
> > > + GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32 *)Targ;
> > > + FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
> > > + *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
> > > + + (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
> > > + - (SecOffset - SecShdr->sh_addr));
> > > + VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > > + GOTEntryRva += (mCoffSectionsOffset[mGOTShindex] -
> mGOTShdr-
> > >sh_addr); // ELF Rva -> COFF Rva
> > > + if (AccumulateCoffGOTEntries((UINT32)GOTEntryRva)) {
> > > + //
> > > + // Relocate GOT entry if it's the first time we run into it
> > > + //
> > > + Targ = mCoffFile + GOTEntryRva;
> > > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX",
> > > + (UINT32)GOTEntryRva,
> > > + *(UINT64 *)Targ);
> > > + *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr +
> > mCoffSectionsOffset[Sym->st_shndx];
> > > + VerboseMsg ("Relocation: 0x%016LX", *(UINT64*)Targ);
> > > + }
> > > + break;
> > > default:
> > > Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64
> > relocation 0x%x.", mInImageName, (unsigned)
> > > ELF_R_TYPE(Rel->r_info));
> > > }
> > > @@ -972,6 +1119,9 @@ WriteRelocations64 (
> > > case R_X86_64_NONE:
> > > case R_X86_64_PC32:
> > > case R_X86_64_PLT32:
> > > + case R_X86_64_GOTPCREL:
> > > + case R_X86_64_GOTPCRELX:
> > > + case R_X86_64_REX_GOTPCRELX:
> > > break;
> > > case R_X86_64_64:
> > > VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> > > @@ -1040,10 +1190,24 @@ WriteRelocations64 (
> > > Error (NULL, 0, 3000, "Not Supported", "This tool does not
> support
> > relocations for ELF with e_machine %u (processor
> > > type).", (unsigned) mEhdr->e_machine);
> > > }
> > > }
> > > + if (mEhdr->e_machine == EM_X86_64 && RelShdr->sh_info ==
> > mGOTShindex) {
> > > + //
> > > + // Tack relocations for GOT entries after other relocations for
> > > + // the section the GOT is in, as it's usually found at the end
> > > + // of the section.
> > > + //
> > > + EmitGOTRelocations();
> > > + }
> > > }
> > > }
> > > }
> > >
> > > + if (mEhdr->e_machine == EM_X86_64) {
> > > + //
> > > + // Just in case GOT is in a section with no other relocations
> > > + //
> > > + EmitGOTRelocations();
> > > + }
> > > //
> > > // Pad by adding empty entries.
> > > //
> > > diff --git a/BaseTools/Source/C/GenFw/elf_common.h
> > b/BaseTools/Source/C/GenFw/elf_common.h
> > > index 766d0e42..50b4e1f2 100644
> > > --- a/BaseTools/Source/C/GenFw/elf_common.h
> > > +++ b/BaseTools/Source/C/GenFw/elf_common.h
> > > @@ -544,6 +544,12 @@ typedef struct {
> > > #define R_386_TLS_DTPMOD32 35 /* GOT entry
> > containing TLS index */
> > > #define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS
> > offset */
> > > #define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS
> > offset */
> > > +#define R_386_SIZE32 38 /* 32-bit symbol size */
> > > +#define R_386_TLS_GOTDESC 39 /* GOT offset for TLS
> > descriptor. */
> > > +#define R_386_TLS_DESC_CALL 40 /* Marker of call through TLS
> > descriptor for relaxation. */
> > > +#define R_386_TLS_DESC 41 /* TLS descriptor
> > containing pointer to code and to argument, returning the TLS offset for
> the
> > > symbol. */
> > > +#define R_386_IRELATIVE 42 /* Adjust indirectly by
> > program base */
> > > +#define R_386_GOT32X 43 /* Load from 32 bit GOT
> > entry, relaxable. */
> > >
> > > /* Null relocation */
> > > #define R_AARCH64_NONE 256 /*
> > No relocation */
> > > @@ -1052,6 +1058,23 @@ typedef struct {
> > > #define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
> > > #define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE
> > GOT entry */
> > > #define R_X86_64_TPOFF32 23 /* Offset in static TLS block
> > */
> > > +#define R_X86_64_PC64 24 /* PC relative 64 bit
> > */
> > > +#define R_X86_64_GOTOFF64 25 /* 64 bit offset to GOT */
> > > +#define R_X86_64_GOTPC32 26 /* 32 bit signed pc relative
> > offset to GOT */
> > > +#define R_X86_64_GOT64 27 /* 64-bit GOT entry
> > offset */
> > > +#define R_X86_64_GOTPCREL64 28 /* 64-bit PC relative
> > offset to GOT entry */
> > > +#define R_X86_64_GOTPC64 29 /* 64-bit PC relative offset to
> > GOT */
> > > +#define R_X86_64_GOTPLT64 30 /* like GOT64, says PLT entry
> > needed */
> > > +#define R_X86_64_PLTOFF64 31 /* 64-bit GOT relative offset
> > to PLT entry */
> > > +#define R_X86_64_SIZE32 32 /* Size of symbol plus
> > 32-bit addend */
> > > +#define R_X86_64_SIZE64 33 /* Size of symbol plus
> > 64-bit addend */
> > > +#define R_X86_64_GOTPC32_TLSDESC 34 /* GOT offset for TLS
> > descriptor. */
> > > +#define R_X86_64_TLSDESC_CALL 35 /* Marker for call
> > through TLS descriptor. */
> > > +#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
> > > +#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by
> > program base */
> > > +#define R_X86_64_RELATIVE64 38 /* 64-bit adjust by program
> > base */
> > > +#define R_X86_64_GOTPCRELX 41 /* Load from 32 bit signed pc
> > relative offset to GOT entry without REX prefix, relaxable. */
> > > +#define R_X86_64_REX_GOTPCRELX 42 /* Load from 32 bit
> > signed pc relative offset to GOT entry with REX prefix, relaxable. */
> > >
> > >
> > > #endif /* !_SYS_ELF_COMMON_H_ */
> > > --
> > > 2.17.1
>
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
2018-06-07 2:17 ` Shi, Steven
@ 2018-06-07 2:24 ` Shi, Steven
0 siblings, 0 replies; 9+ messages in thread
From: Shi, Steven @ 2018-06-07 2:24 UTC (permalink / raw)
To: Gao, Liming, Zenith432, edk2-devel@lists.01.org
Hi Zenith,
BTW, besides the build pass, did you try to run a Uefi binary, e.g. a simple shell application, which contain the GOTPCREL relocations? If yes. Please send out your test case code as well. I appreciate if you could contribute your test cases as the patch together.
Steven Shi
Intel\SSG\STO\UEFI Firmware
Tel: +86 021-61166522
iNet: 821-6522
> -----Original Message-----
> From: Shi, Steven
> Sent: Thursday, June 7, 2018 10:18 AM
> To: Shi, Steven <steven.shi@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Zenith432 <zenith432@users.sourceforge.net>;
> edk2-devel@lists.01.org
> Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> GenFw
>
> Please see more details in
> https://bugzilla.tianocore.org/show_bug.cgi?id=970
>
>
> Steven Shi
> Intel\SSG\STO\UEFI Firmware
>
> Tel: +86 021-61166522
> iNet: 821-6522
>
>
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> Shi,
> > Steven
> > Sent: Thursday, June 7, 2018 10:16 AM
> > To: Gao, Liming <liming.gao@intel.com>; Zenith432
> > <zenith432@users.sourceforge.net>; edk2-devel@lists.01.org
> > Subject: Re: [edk2] [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support
> > to GenFw
> >
> > Yes. If we disable the '#pragma GCC visibility push (hidden)' in
> > ProcessorBind.h, the GOTPCREL support is mandatory. 3rd party module
> > build might need it. It's more complete to add GOTPCREL support.
> >
> > The hidden #pragma can hide all ELF symbols' visibility, including 'extern'
> > functions, which is to let Linux compilers aware that we don’t need loading
> > dynamic link library in Uefi runing, please not emit the GOTPCREL based
> > relocations in the obj file, and we will ensure the linker can get all extern
> > functions statically solved. The reason of not emitting GOTPCREL based
> > relocations is because it is hard to convert the GOTPCREL based relocations
> > in ELF binary to PE/COFF related relocations, and our current GenFw has
> not
> > supported them. I'm glade if we can add the GOTPCREL support in GenFW
> to
> > totally solve this problem.
> >
> > Steven Shi
> > Intel\SSG\STO\UEFI Firmware
> >
> > Tel: +86 021-61166522
> > iNet: 821-6522
> >
> > > -----Original Message-----
> > > From: Gao, Liming
> > > Sent: Thursday, June 7, 2018 9:32 AM
> > > To: Zenith432 <zenith432@users.sourceforge.net>; edk2-
> > devel@lists.01.org
> > > Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> > > <yonghong.zhu@intel.com>
> > > Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> > > GenFw
> > >
> > > What's purpose to support GOTPCREL in GenFw? Could you introduce
> your
> > > usage model?
> > >
> > > > -----Original Message-----
> > > > From: Zenith432 [mailto:zenith432@users.sourceforge.net]
> > > > Sent: Thursday, June 7, 2018 2:01 AM
> > > > To: edk2-devel@lists.01.org
> > > > Cc: Shi, Steven <steven.shi@intel.com>; Zhu, Yonghong
> > > <yonghong.zhu@intel.com>; Gao, Liming <liming.gao@intel.com>
> > > > Subject: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> > GenFw
> > > >
> > > > Adds support for the following X64 ELF relocations to GenFw
> > > > R_X86_64_GOTPCREL
> > > > R_X86_64_GOTPCRELX
> > > > R_X86_64_REX_GOTPCRELX
> > > >
> > > > CC: Shi Steven <steven.shi@intel.com>
> > > > CC: Yonghong Zhu <yonghong.zhu@intel.com>
> > > > CC: Liming Gao <liming.gao@intel.com>
> > > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > > Signed-off-by: Zenith432 <zenith432@users.sourceforge.net>
> > > > ---
> > > > BaseTools/Source/C/GenFw/Elf64Convert.c | 166
> > > +++++++++++++++++++++++-
> > > > BaseTools/Source/C/GenFw/elf_common.h | 23 ++++
> > > > 2 files changed, 188 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > > index c39bdff0..d2f9bb46 100644
> > > > --- a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > > +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > > @@ -94,6 +94,15 @@ STATIC Elf_Ehdr *mEhdr;
> > > > STATIC Elf_Shdr *mShdrBase;
> > > > STATIC Elf_Phdr *mPhdrBase;
> > > >
> > > > +//
> > > > +// GOT information
> > > > +//
> > > > +STATIC Elf_Shdr *mGOTShdr = NULL;
> > > > +STATIC UINT32 mGOTShindex = 0;
> > > > +STATIC UINT32 *mGOTCoffEntries = NULL;
> > > > +STATIC UINT32 mGOTMaxCoffEntries = 0;
> > > > +STATIC UINT32 mGOTNumCoffEntries = 0;
> > > > +
> > > > //
> > > > // Coff information
> > > > //
> > > > @@ -322,6 +331,117 @@ GetSymName (
> > > > return StrtabContents + Sym->st_name;
> > > > }
> > > >
> > > > +//
> > > > +// Find the ELF section hosting the GOT from an ELF Rva
> > > > +// of a single GOT entry. Normally, GOT is placed in
> > > > +// ELF .text section, so assume once we find in which
> > > > +// section the GOT is, all GOT entries are there, and
> > > > +// just verify this.
> > > > +//
> > > > +STATIC
> > > > +VOID
> > > > +FindElfGOTSectionFromGOTEntryElfRva (
> > > > + Elf64_Addr GOTEntryElfRva
> > > > + )
> > > > +{
> > > > + UINT32 i;
> > > > + if (mGOTShdr != NULL) {
> > > > + if (GOTEntryElfRva >= mGOTShdr->sh_addr &&
> > > > + GOTEntryElfRva < mGOTShdr->sh_addr + mGOTShdr->sh_size)
> > > > + return;
> > > > + Error (NULL, 0, 3000, "Unsupported",
> > > "FindElfGOTSectionFromGOTEntryElfRva: GOT entries found in multiple
> > > sections.");
> > > > + exit(EXIT_FAILURE);
> > > > + }
> > > > + for (i = 0; i < mEhdr->e_shnum; i++) {
> > > > + Elf_Shdr *shdr = GetShdrByIndex(i);
> > > > + if (GOTEntryElfRva >= shdr->sh_addr &&
> > > > + GOTEntryElfRva < shdr->sh_addr + shdr->sh_size) {
> > > > + mGOTShdr = shdr;
> > > > + mGOTShindex = i;
> > > > + return;
> > > > + }
> > > > + }
> > > > + Error (NULL, 0, 3000, "Invalid",
> > "FindElfGOTSectionFromGOTEntryElfRva:
> > > ElfRva 0x%016LX for GOT entry not found in any section.",
> > > > GOTEntryElfRva);
> > > > + exit(EXIT_FAILURE);
> > > > +}
> > > > +
> > > > +//
> > > > +// Stores locations of GOT entries in COFF image.
> > > > +// Returns TRUE if GOT entry is new.
> > > > +// Simple implementation as number of GOT
> > > > +// entries is expected to be low.
> > > > +//
> > > > +
> > > > +STATIC
> > > > +BOOLEAN
> > > > +AccumulateCoffGOTEntries (
> > > > + UINT32 GOTCoffEntry
> > > > + )
> > > > +{
> > > > + UINT32 i;
> > > > + if (mGOTCoffEntries != NULL) {
> > > > + for (i = 0; i < mGOTNumCoffEntries; i++)
> > > > + if (mGOTCoffEntries[i] == GOTCoffEntry)
> > > > + return FALSE;
> > > > + }
> > > > + if (mGOTCoffEntries == NULL) {
> > > > + mGOTCoffEntries = (UINT32*)malloc(5 * sizeof *mGOTCoffEntries);
> > > > + if (mGOTCoffEntries == NULL) {
> > > > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > > > + }
> > > > + assert (mGOTCoffEntries != NULL);
> > > > + mGOTMaxCoffEntries = 5;
> > > > + mGOTNumCoffEntries = 0;
> > > > + } else if (mGOTNumCoffEntries == mGOTMaxCoffEntries) {
> > > > + mGOTCoffEntries = (UINT32*)realloc(mGOTCoffEntries, 2 *
> > > mGOTMaxCoffEntries * sizeof *mGOTCoffEntries);
> > > > + if (mGOTCoffEntries == NULL) {
> > > > + Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
> > > > + }
> > > > + assert (mGOTCoffEntries != NULL);
> > > > + mGOTMaxCoffEntries += mGOTMaxCoffEntries;
> > > > + }
> > > > + mGOTCoffEntries[mGOTNumCoffEntries++] = GOTCoffEntry;
> > > > + return TRUE;
> > > > +}
> > > > +
> > > > +STATIC
> > > > +int
> > > > +__comparator (
> > > > + const void* lhs,
> > > > + const void* rhs
> > > > + )
> > > > +{
> > > > + if (*(const UINT32*)lhs < *(const UINT32*)rhs)
> > > > + return -1;
> > > > + return *(const UINT32*)lhs > *(const UINT32*)rhs;
> > > > +}
> > > > +
> > > > +STATIC
> > > > +VOID
> > > > +EmitGOTRelocations (
> > > > + VOID
> > > > + )
> > > > +{
> > > > + UINT32 i;
> > > > + if (mGOTCoffEntries == NULL)
> > > > + return;
> > > > + qsort(
> > > > + mGOTCoffEntries,
> > > > + mGOTNumCoffEntries,
> > > > + sizeof *mGOTCoffEntries,
> > > > + __comparator);
> > > > + for (i = 0; i < mGOTNumCoffEntries; i++) {
> > > > + VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> > > mGOTCoffEntries[i]);
> > > > + CoffAddFixup(
> > > > + mGOTCoffEntries[i],
> > > > + EFI_IMAGE_REL_BASED_DIR64);
> > > > + }
> > > > + free(mGOTCoffEntries);
> > > > + mGOTCoffEntries = NULL;
> > > > + mGOTMaxCoffEntries = 0;
> > > > + mGOTNumCoffEntries = 0;
> > > > +}
> > > > +
> > > > //
> > > > // Elf functions interface implementation
> > > > //
> > > > @@ -698,7 +818,7 @@ WriteSections64 (
> > > > // section that applies to the entire binary, and which will have its
> > > section
> > > > // index set to #0 (which is a NULL section with the SHF_ALLOC bit
> > > cleared).
> > > > //
> > > > - // In the absence of GOT based relocations (which we currently don't
> > > support),
> > > > + // In the absence of GOT based relocations,
> > > > // this RELA section will contain redundant R_xxx_RELATIVE
> > relocations,
> > > one
> > > > // for every R_xxx_xx64 relocation appearing in the per-section RELA
> > > sections.
> > > > // (i.e., .rela.text and .rela.data)
> > > > @@ -780,6 +900,7 @@ WriteSections64 (
> > > > // Determine how to handle each relocation type based on the
> > > machine type.
> > > > //
> > > > if (mEhdr->e_machine == EM_X86_64) {
> > > > + Elf64_Addr GOTEntryRva;
> > > > switch (ELF_R_TYPE(Rel->r_info)) {
> > > > case R_X86_64_NONE:
> > > > break;
> > > > @@ -834,6 +955,32 @@ WriteSections64 (
> > > > - (SecOffset - SecShdr->sh_addr));
> > > > VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > > > break;
> > > > + case R_X86_64_GOTPCREL:
> > > > + case R_X86_64_GOTPCRELX:
> > > > + case R_X86_64_REX_GOTPCRELX:
> > > > + VerboseMsg ("R_X86_64_GOTPCREL family");
> > > > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
> > > > + (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
> > > > + *(UINT32 *)Targ);
> > > > + GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32
> *)Targ;
> > > > + FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
> > > > + *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
> > > > + + (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
> > > > + - (SecOffset - SecShdr->sh_addr));
> > > > + VerboseMsg ("Relocation: 0x%08X", *(UINT32 *)Targ);
> > > > + GOTEntryRva += (mCoffSectionsOffset[mGOTShindex] -
> > mGOTShdr-
> > > >sh_addr); // ELF Rva -> COFF Rva
> > > > + if (AccumulateCoffGOTEntries((UINT32)GOTEntryRva)) {
> > > > + //
> > > > + // Relocate GOT entry if it's the first time we run into it
> > > > + //
> > > > + Targ = mCoffFile + GOTEntryRva;
> > > > + VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX",
> > > > + (UINT32)GOTEntryRva,
> > > > + *(UINT64 *)Targ);
> > > > + *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr +
> > > mCoffSectionsOffset[Sym->st_shndx];
> > > > + VerboseMsg ("Relocation: 0x%016LX", *(UINT64*)Targ);
> > > > + }
> > > > + break;
> > > > default:
> > > > Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64
> > > relocation 0x%x.", mInImageName, (unsigned)
> > > > ELF_R_TYPE(Rel->r_info));
> > > > }
> > > > @@ -972,6 +1119,9 @@ WriteRelocations64 (
> > > > case R_X86_64_NONE:
> > > > case R_X86_64_PC32:
> > > > case R_X86_64_PLT32:
> > > > + case R_X86_64_GOTPCREL:
> > > > + case R_X86_64_GOTPCRELX:
> > > > + case R_X86_64_REX_GOTPCRELX:
> > > > break;
> > > > case R_X86_64_64:
> > > > VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X",
> > > > @@ -1040,10 +1190,24 @@ WriteRelocations64 (
> > > > Error (NULL, 0, 3000, "Not Supported", "This tool does not
> > support
> > > relocations for ELF with e_machine %u (processor
> > > > type).", (unsigned) mEhdr->e_machine);
> > > > }
> > > > }
> > > > + if (mEhdr->e_machine == EM_X86_64 && RelShdr->sh_info ==
> > > mGOTShindex) {
> > > > + //
> > > > + // Tack relocations for GOT entries after other relocations for
> > > > + // the section the GOT is in, as it's usually found at the end
> > > > + // of the section.
> > > > + //
> > > > + EmitGOTRelocations();
> > > > + }
> > > > }
> > > > }
> > > > }
> > > >
> > > > + if (mEhdr->e_machine == EM_X86_64) {
> > > > + //
> > > > + // Just in case GOT is in a section with no other relocations
> > > > + //
> > > > + EmitGOTRelocations();
> > > > + }
> > > > //
> > > > // Pad by adding empty entries.
> > > > //
> > > > diff --git a/BaseTools/Source/C/GenFw/elf_common.h
> > > b/BaseTools/Source/C/GenFw/elf_common.h
> > > > index 766d0e42..50b4e1f2 100644
> > > > --- a/BaseTools/Source/C/GenFw/elf_common.h
> > > > +++ b/BaseTools/Source/C/GenFw/elf_common.h
> > > > @@ -544,6 +544,12 @@ typedef struct {
> > > > #define R_386_TLS_DTPMOD32 35 /* GOT entry
> > > containing TLS index */
> > > > #define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS
> > > offset */
> > > > #define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS
> > > offset */
> > > > +#define R_386_SIZE32 38 /* 32-bit symbol size */
> > > > +#define R_386_TLS_GOTDESC 39 /* GOT offset for TLS
> > > descriptor. */
> > > > +#define R_386_TLS_DESC_CALL 40 /* Marker of call through TLS
> > > descriptor for relaxation. */
> > > > +#define R_386_TLS_DESC 41 /* TLS descriptor
> > > containing pointer to code and to argument, returning the TLS offset for
> > the
> > > > symbol. */
> > > > +#define R_386_IRELATIVE 42 /* Adjust indirectly by
> > > program base */
> > > > +#define R_386_GOT32X 43 /* Load from 32 bit GOT
> > > entry, relaxable. */
> > > >
> > > > /* Null relocation */
> > > > #define R_AARCH64_NONE 256 /*
> > > No relocation */
> > > > @@ -1052,6 +1058,23 @@ typedef struct {
> > > > #define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
> > > > #define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE
> > > GOT entry */
> > > > #define R_X86_64_TPOFF32 23 /* Offset in static TLS block
> > > */
> > > > +#define R_X86_64_PC64 24 /* PC relative 64 bit
> > > */
> > > > +#define R_X86_64_GOTOFF64 25 /* 64 bit offset to GOT */
> > > > +#define R_X86_64_GOTPC32 26 /* 32 bit signed pc relative
> > > offset to GOT */
> > > > +#define R_X86_64_GOT64 27 /* 64-bit GOT entry
> > > offset */
> > > > +#define R_X86_64_GOTPCREL64 28 /* 64-bit PC relative
> > > offset to GOT entry */
> > > > +#define R_X86_64_GOTPC64 29 /* 64-bit PC relative offset to
> > > GOT */
> > > > +#define R_X86_64_GOTPLT64 30 /* like GOT64, says PLT entry
> > > needed */
> > > > +#define R_X86_64_PLTOFF64 31 /* 64-bit GOT relative offset
> > > to PLT entry */
> > > > +#define R_X86_64_SIZE32 32 /* Size of symbol plus
> > > 32-bit addend */
> > > > +#define R_X86_64_SIZE64 33 /* Size of symbol plus
> > > 64-bit addend */
> > > > +#define R_X86_64_GOTPC32_TLSDESC 34 /* GOT offset for TLS
> > > descriptor. */
> > > > +#define R_X86_64_TLSDESC_CALL 35 /* Marker for call
> > > through TLS descriptor. */
> > > > +#define R_X86_64_TLSDESC 36 /* TLS descriptor. */
> > > > +#define R_X86_64_IRELATIVE 37 /* Adjust indirectly by
> > > program base */
> > > > +#define R_X86_64_RELATIVE64 38 /* 64-bit adjust by program
> > > base */
> > > > +#define R_X86_64_GOTPCRELX 41 /* Load from 32 bit signed pc
> > > relative offset to GOT entry without REX prefix, relaxable. */
> > > > +#define R_X86_64_REX_GOTPCRELX 42 /* Load from 32 bit
> > > signed pc relative offset to GOT entry with REX prefix, relaxable. */
> > > >
> > > >
> > > > #endif /* !_SYS_ELF_COMMON_H_ */
> > > > --
> > > > 2.17.1
> >
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
[not found] <1501305711.1573406.1528351473858.ref@mail.yahoo.com>
@ 2018-06-07 6:04 ` Zenith432
0 siblings, 0 replies; 9+ messages in thread
From: Zenith432 @ 2018-06-07 6:04 UTC (permalink / raw)
To: LimingGao; +Cc: StevenShi, YonghongZhu, edk2-devel@lists.01.org
This issue only applies to GCC/ELF target.
When using -fpie ("small pie" model which is GCC extension to SYSV ABI) - eliminates nearly all emission of GOTPCREL in object code (= loading addresses from the GOT.)
However, when optimizing for size (-Os), sometimes emitted code only needs to compute address of external symbol, not access data under it. For example, when doing pointer arithmetic or passing address as an argument - the code generator concludes that loading the address from GOT is beneficial to reduced code size (since address can be loaded from GOT using push or add instructions, not just mov instruction.) It then occasionally emits GOTPCREL.
The emission of GOTPCREL is completely suppressed by putting __attribute__((visibility("hidden")) on declaration of external symbol, or using
#pragma GCC push visibility("hidden")
to achieve this on all exernal symbols.
This is included in MdePkg/Include/X64/ProcessorBind.h - however only turned on for non-LTO builds.
When using "-flto -DUSING_LTO" - GCC can sometimes emit GOTPCREL for pointer arithmetic on external symbols. I have instance of this which is not part of EDK2 (the GOTPCREL is emitted when "-flto -DUSING_LTO" is enabled.)
There is also an instance of emitted PCREL occuring when building OvmfX64.dsc if using "-fno-lto -DUSING_LTO" (i.e. no LTO, but suppress the #pragma).
Adding GOTPCREL support to GenFw can handle a few occasional cases if this relocation is emitted by GCC.
I no longer ask that "#pragma GCC push visibility("hidden")" be removed for non-LTO builds, although it's a sweeping solution because if affects all symbols. It is enough to put __attribute__((visibility("hidden")) on affected symbols. Additionally, maybe scope be reduced with "#if defined(__GNUC__) && !defined(__clang__) && defined(__ELF__)" instead of "#if defined(__GNUC__)" so pragma affects only GCC/ELF.
I don't have any standalone samples that are not part of a large build. If you want standalone test cases - I only have time next week to construct some.
As for the code itself
- I did test of course on the cases that occur in the build.
- Patch is constructed so that if no GOTPCREL are found in ELF binary - there's no effect on today's function of GenFw other then testing for NULL in a couple of places in function WriteLocation64. In this sense the patch is safe - does not affect function of GenFw on previously suppoted ELF binaries that already works. For ELF binaries with GOTPCREL today GenFw breaks with an error.
- ELF with multiple text or data sections is supported. However, the order of events in the added code the patch makes to WriteSection64 depends on text sections being processed first and GOT being emitted in one of the text sections. This is the case today (ld script emits GOT in .text). I don't believe this is likely to change, however, if it's important to elminate this minor order dependence - I can do so.
- I hope someone reviews the code carefully :)
- I see other patches to Elf64Convert.c were posted so this patch probably needs merging before commit.
Regards
--------------------------------------------
On Thu, 6/7/18, Gao, Liming <liming.gao@intel.com> wrote:
Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
To: "Zenith432" <zenith432@users.sourceforge.net>, "edk2-devel@lists.01.org" <edk2-devel@lists.01.org>
Cc: "Shi, Steven" <steven.shi@intel.com>, "Zhu, Yonghong" <yonghong.zhu@intel.com>
Date: Thursday, June 7, 2018, 4:32 AM
What's purpose to support GOTPCREL in GenFw?
Could you introduce your usage model?
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
[not found] <1082615057.1616071.1528351716579.ref@mail.yahoo.com>
@ 2018-06-07 6:08 ` Zenith432
2018-06-08 0:32 ` Shi, Steven
0 siblings, 1 reply; 9+ messages in thread
From: Zenith432 @ 2018-06-07 6:08 UTC (permalink / raw)
To: StevenShi; +Cc: LimingGao, edk2-devel@lists.01.org
As I said in other mailing - I only tested on cases in builld. If you want standalone test cases I only have time next week to make some.
--------------------------------------------
On Thu, 6/7/18, Shi, Steven <steven.shi@intel.com> wrote:
Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
To: "Gao, Liming" <liming.gao@intel.com>, "Zenith432" <zenith432@users.sourceforge.net>, "edk2-devel@lists.01.org" <edk2-devel@lists.01.org>
Date: Thursday, June 7, 2018, 5:24 AM
Hi Zenith,
BTW,
besides the build pass, did you try to run a Uefi binary,
e.g. a simple shell application, which contain the GOTPCREL
relocations? If yes. Please send out your test case code as
well. I appreciate if you could contribute your test cases
as the patch together.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
[not found] <443019651.1678894.1528375563310.ref@mail.yahoo.com>
@ 2018-06-07 12:46 ` Zenith432
0 siblings, 0 replies; 9+ messages in thread
From: Zenith432 @ 2018-06-07 12:46 UTC (permalink / raw)
To: LimingGao; +Cc: edk2-devel@lists.01.org, StevenShi
There is a mistake in sign in the patch I posted
=====
diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
--- a/BaseTools/Source/C/GenFw/Elf64Convert.c
+++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
@@ -962,7 +962,7 @@ WriteSections64 (
VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X",
(UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)),
*(UINT32 *)Targ);
- GOTEntryRva = Rel->r_offset - Rel->r_addend + *(UINT32 *)Targ;
+ GOTEntryRva = Rel->r_offset - Rel->r_addend + *(INT32 *)Targ;
FindElfGOTSectionFromGOTEntryElfRva(GOTEntryRva);
*(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
+ (mCoffSectionsOffset[mGOTShindex] - mGOTShdr->sh_addr)
=====
(Displacement should be sign-extended to 64 bit for this calc.)
It did not surface because in single-text section ELF file, displacement from instructions to GOT entries are always positive.
I will repost the whole patch with this change.
--------------------------------------------
On Thu, 6/7/18, Gao, Liming <liming.gao@intel.com> wrote:
Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
To: "Zenith432" <zenith432@users.sourceforge.net>, "edk2-devel@lists.01.org" <edk2-devel@lists.01.org>
Cc: "Shi, Steven" <steven.shi@intel.com>, "Zhu, Yonghong" <yonghong.zhu@intel.com>
Date: Thursday, June 7, 2018, 4:32 AM
What's purpose to support GOTPCREL in GenFw?
Could you introduce your usage model?
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw
2018-06-07 6:08 ` Zenith432
@ 2018-06-08 0:32 ` Shi, Steven
0 siblings, 0 replies; 9+ messages in thread
From: Shi, Steven @ 2018-06-08 0:32 UTC (permalink / raw)
To: Zenith432, Gao, Liming; +Cc: edk2-devel@lists.01.org
Next week is OK, take your time. I appreciate the test cases with build steps, thanks!
BTW, I'm not sure where is the right place in edk2 to submit a patch's test cases, but I do welcome the test case contribution.
Steven Shi
Intel\SSG\STO\UEFI Firmware
Tel: +86 021-61166522
iNet: 821-6522
> -----Original Message-----
> From: Zenith432 [mailto:zenith432@users.sourceforge.net]
> Sent: Thursday, June 7, 2018 2:09 PM
> To: Shi, Steven <steven.shi@intel.com>
> Cc: Gao, Liming <liming.gao@intel.com>; edk2-devel@lists.01.org
> Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> GenFw
>
> As I said in other mailing - I only tested on cases in builld. If you want
> standalone test cases I only have time next week to make some.
>
> --------------------------------------------
> On Thu, 6/7/18, Shi, Steven <steven.shi@intel.com> wrote:
>
> Subject: RE: [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to
> GenFw
> To: "Gao, Liming" <liming.gao@intel.com>, "Zenith432"
> <zenith432@users.sourceforge.net>, "edk2-devel@lists.01.org" <edk2-
> devel@lists.01.org>
> Date: Thursday, June 7, 2018, 5:24 AM
>
> Hi Zenith,
> BTW,
> besides the build pass, did you try to run a Uefi binary,
> e.g. a simple shell application, which contain the GOTPCREL
> relocations? If yes. Please send out your test case code as
> well. I appreciate if you could contribute your test cases
> as the patch together.
>
^ permalink raw reply [flat|nested] 9+ messages in thread
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2018-06-06 18:01 ` [PATCH] BaseTools/GenFw: Add X64 GOTPCREL Support to GenFw Zenith432
2018-06-07 1:32 ` Gao, Liming
2018-06-07 2:15 ` Shi, Steven
2018-06-07 2:17 ` Shi, Steven
2018-06-07 2:24 ` Shi, Steven
[not found] <1501305711.1573406.1528351473858.ref@mail.yahoo.com>
2018-06-07 6:04 ` Zenith432
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2018-06-07 6:08 ` Zenith432
2018-06-08 0:32 ` Shi, Steven
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2018-06-07 12:46 ` Zenith432
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