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From: "Yao, Jiewen" <jiewen.yao@intel.com>
To: Paulo Alcantara <paulo@paulo.ac>,
	"edk2-devel@lists.01.org" <edk2-devel@lists.01.org>
Cc: Laszlo Ersek <lersek@redhat.com>, "Dong, Eric" <eric.dong@intel.com>
Subject: Re: [RFC v4 5/6] UefiCpuPkg/CpuExceptionHandlerLib: Ensure valid frame/stack pointers
Date: Thu, 4 Jan 2018 01:07:12 +0000	[thread overview]
Message-ID: <74D8A39837DF1E4DA445A8C0B3885C503AA6F907@shsmsx102.ccr.corp.intel.com> (raw)
In-Reply-To: <836f7f2205e91c16d7c427c5b6e127f4a4dfa62e.1514517573.git.paulo@paulo.ac>

Some suggestion:

1) Would you please use meaning definition for BIT2?

if ((SegmentSelector & BIT2) == 0) {

2) Can we just use (SegmentSelector & ~0x7) for below?

((SegmentSelector >> 3) * 8)

3) Below calculation seems wrong. Should it be: SegDescLimitInBytes = (UINTN)SegDescLimit * SIZE_4KB + (SIZE_4KB - 1) ?

  if (SegmentDescriptor->Bits.G == 1) {
    SegDescLimitInBytes = (UINTN)SegDescLimit * SIZE_4KB;

Thank you
Yao Jiewen


> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Paulo
> Alcantara
> Sent: Friday, December 29, 2017 12:40 PM
> To: edk2-devel@lists.01.org
> Cc: Laszlo Ersek <lersek@redhat.com>; Dong, Eric <eric.dong@intel.com>
> Subject: [edk2] [RFC v4 5/6] UefiCpuPkg/CpuExceptionHandlerLib: Ensure valid
> frame/stack pointers
> 
> Validate all possible memory dereferences during stack traces in IA32
> and X64 CPU exceptions.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Requested-by: Brian Johnson <brian.johnson@hpe.com>
> Requested-by: Jiewen Yao <jiewen.yao@intel.com>
> Signed-off-by: Paulo Alcantara <paulo@paulo.ac>
> ---
>  UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c |
> 143 +++++++++++++++++++-
>  UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c  |
> 75 +++++++++-
>  2 files changed, 210 insertions(+), 8 deletions(-)
> 
> diff --git
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
> index 25e02fbbc1..9b52d4f6d2 100644
> --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
> +++
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c
> @@ -398,6 +398,96 @@ DumpCpuContext (
>      );
>  }
> 
> +/**
> +  Check if a logical address is valid.
> +
> +  @param[in]  SystemContext      Pointer to EFI_SYSTEM_CONTEXT.
> +  @param[in]  SegmentSelector    Segment selector.
> +  @param[in]  Offset             Offset or logical address.
> +**/
> +STATIC
> +BOOLEAN
> +IsLogicalAddressValid (
> +  IN  EFI_SYSTEM_CONTEXT   SystemContext,
> +  IN  UINT16               SegmentSelector,
> +  IN  UINTN                Offset
> +  )
> +{
> +  IA32_SEGMENT_DESCRIPTOR  *SegmentDescriptor;
> +  UINT32                   SegDescBase;
> +  UINT32                   SegDescLimit;
> +  UINTN                    SegDescLimitInBytes;
> +
> +  //
> +  // Check for valid input parameters
> +  //
> +  if (SegmentSelector == 0 || Offset == 0) {
> +    return FALSE;
> +  }
> +
> +  //
> +  // Check whether to look for a segment descriptor in GDT or LDT table
> +  //
> +  if ((SegmentSelector & BIT2) == 0) {
> +    //
> +    // Get segment descriptor from GDT table
> +    //
> +    SegmentDescriptor =
> +      (IA32_SEGMENT_DESCRIPTOR *)(
> +        (UINTN)SystemContext.SystemContextIa32->Gdtr[0] +
> +        ((SegmentSelector >> 3) * 8)
> +        );
> +  } else {
> +    //
> +    // Get segment descriptor from LDT table
> +    //
> +    SegmentDescriptor =
> +      (IA32_SEGMENT_DESCRIPTOR *)(
> +        (UINTN)SystemContext.SystemContextIa32->Ldtr +
> +        ((SegmentSelector >> 3) * 8)
> +        );
> +  }
> +
> +  //
> +  // Get segment descriptor's base address
> +  //
> +  SegDescBase = SegmentDescriptor->Bits.BaseLow |
> +    (SegmentDescriptor->Bits.BaseMid << 16) |
> +    (SegmentDescriptor->Bits.BaseHigh << 24);
> +
> +  //
> +  // Get segment descriptor's limit
> +  //
> +  SegDescLimit = SegmentDescriptor->Bits.LimitLow |
> +    (SegmentDescriptor->Bits.LimitHigh << 16);
> +
> +  //
> +  // Calculate segment descriptor's limit in bytes
> +  //
> +  if (SegmentDescriptor->Bits.G == 1) {
> +    SegDescLimitInBytes = (UINTN)SegDescLimit * SIZE_4KB;
> +  } else {
> +    SegDescLimitInBytes = SegDescLimit;
> +  }
> +
> +  //
> +  // Make sure to not access beyond a segment limit boundary
> +  //
> +  if (Offset + SegDescBase > SegDescLimitInBytes) {
> +    return FALSE;
> +  }
> +
> +  //
> +  // Check if the translated logical address (or linear address) is valid
> +  //
> +  return IsLinearAddressValid (
> +    SystemContext.SystemContextIa32->Cr0,
> +    SystemContext.SystemContextIa32->Cr3,
> +    SystemContext.SystemContextIa32->Cr4,
> +    Offset + SegDescBase
> +    );
> +}
> +
>  /**
>    Dump stack trace.
> 
> @@ -459,6 +549,20 @@ DumpStackTrace (
>    InternalPrintMessage ("\nCall trace:\n");
> 
>    for (;;) {
> +    //
> +    // Check for valid frame pointer
> +    //
> +    if (!IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)Ebp + 4) ||
> +        !IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)Ebp)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid frame "
> +                            "pointer at 0x%08x\n", __FUNCTION__, Ebp);
> +      break;
> +    }
> +
>      //
>      // Print stack frame in the following format:
>      //
> @@ -588,6 +692,16 @@ DumpImageModuleNames (
>    // Walk through call stack and find next module names
>    //
>    for (;;) {
> +    if (!IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)Ebp) ||
> +        !IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)Ebp + 4)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid frame "
> +                            "pointer at 0x%08x\n", __FUNCTION__, Ebp);
> +    }
> +
>      //
>      // Set EIP with return address from current stack frame
>      //
> @@ -651,16 +765,23 @@ DumpImageModuleNames (
>  /**
>    Dump stack contents.
> 
> -  @param[in]  CurrentEsp         Current stack pointer address.
> +  @param[in]  SystemContext       Pointer to EFI_SYSTEM_CONTEXT.
>    @param[in]  UnwoundStacksCount  Count of unwound stack frames.
>  **/
>  STATIC
>  VOID
>  DumpStackContents (
> -  IN UINT32  CurrentEsp,
> -  IN INTN    UnwoundStacksCount
> +  IN  EFI_SYSTEM_CONTEXT  SystemContext,
> +  IN  INTN                UnwoundStacksCount
>    )
>  {
> +  UINT32 CurrentEsp;
> +
> +  //
> +  // Get current stack pointer
> +  //
> +  CurrentEsp = SystemContext.SystemContextIa32->Esp;
> +
>    //
>    // Check for proper stack alignment
>    //
> @@ -674,6 +795,20 @@ DumpStackContents (
>    //
>    InternalPrintMessage ("\nStack dump:\n");
>    while (UnwoundStacksCount-- > 0) {
> +    //
> +    // Check for a valid stack pointer address
> +    //
> +    if (!IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)CurrentEsp) ||
> +        !IsLogicalAddressValid (SystemContext,
> +                                SystemContext.SystemContextIa32->Ss,
> +                                (UINTN)CurrentEsp + 4)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid stack "
> +                            "pointer at 0x%08x\n", __FUNCTION__,
> CurrentEsp);
> +      break;
> +    }
> +
>      InternalPrintMessage (
>        "0x%08x: %08x %08x\n",
>        CurrentEsp,
> @@ -720,5 +855,5 @@ DumpImageAndCpuContent (
>    //
>    // Dump stack contents
>    //
> -  DumpStackContents (SystemContext.SystemContextIa32->Esp,
> UnwoundStacksCount);
> +  DumpStackContents (SystemContext, UnwoundStacksCount);
>  }
> diff --git
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
> index d3a3878b3d..8067c34122 100644
> --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
> +++
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchExceptionHandler.c
> @@ -401,16 +401,26 @@ DumpCpuContext (
>  /**
>    Dump stack contents.
> 
> -  @param[in]  CurrentRsp         Current stack pointer address.
> +  @param[in]  SystemContext       Pointer to EFI_SYSTEM_CONTEXT.
>    @param[in]  UnwoundStacksCount  Count of unwound stack frames.
>  **/
>  STATIC
>  VOID
>  DumpStackContents (
> -  IN UINT64  CurrentRsp,
> -  IN INTN    UnwoundStacksCount
> +  IN  EFI_SYSTEM_CONTEXT  SystemContext,
> +  IN  INTN                UnwoundStacksCount
>    )
>  {
> +  UINT64  CurrentRsp;
> +  UINTN   Cr0;
> +  UINTN   Cr3;
> +  UINTN   Cr4;
> +
> +  //
> +  // Get current stack pointer
> +  //
> +  CurrentRsp = SystemContext.SystemContextX64->Rsp;
> +
>    //
>    // Check for proper stack pointer alignment
>    //
> @@ -419,11 +429,28 @@ DumpStackContents (
>      return;
>    }
> 
> +  //
> +  // Get system control registers
> +  //
> +  Cr0 = SystemContext.SystemContextX64->Cr0;
> +  Cr3 = SystemContext.SystemContextX64->Cr3;
> +  Cr4 = SystemContext.SystemContextX64->Cr4;
> +
>    //
>    // Dump out stack contents
>    //
>    InternalPrintMessage ("\nStack dump:\n");
>    while (UnwoundStacksCount-- > 0) {
> +    //
> +    // Check for a valid stack pointer address
> +    //
> +    if (!IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)CurrentRsp) ||
> +        !IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)CurrentRsp + 8)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid stack "
> +                            "pointer at 0x%016lx\n", __FUNCTION__,
> CurrentRsp);
> +      break;
> +    }
> +
>      InternalPrintMessage (
>        "0x%016lx: %016lx %016lx\n",
>        CurrentRsp,
> @@ -457,6 +484,9 @@ DumpImageModuleNames (
>    CHAR8       *PdbFileName;
>    UINT64      Rbp;
>    UINTN       LastImageBase;
> +  UINTN       Cr0;
> +  UINTN       Cr3;
> +  UINTN       Cr4;
> 
>    //
>    // Set current RIP address
> @@ -516,10 +546,27 @@ DumpImageModuleNames (
>      InternalPrintMessage ("%a\n", PdbAbsoluteFilePath);
>    }
> 
> +  //
> +  // Get system control registers
> +  //
> +  Cr0 = SystemContext.SystemContextX64->Cr0;
> +  Cr3 = SystemContext.SystemContextX64->Cr3;
> +  Cr4 = SystemContext.SystemContextX64->Cr4;
> +
>    //
>    // Walk through call stack and find next module names
>    //
>    for (;;) {
> +    //
> +    // Check for a valid frame pointer
> +    //
> +    if (!IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)Rbp + 8) ||
> +        !IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)Rbp)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid frame "
> +                            "pointer at 0x%016lx\n", __FUNCTION__,
> Rbp);
> +      break;
> +    }
> +
>      //
>      // Set RIP with return address from current stack frame
>      //
> @@ -604,6 +651,9 @@ DumpStackTrace (
>    UINT64  Rbp;
>    UINTN   ImageBase;
>    CHAR8   *PdbFileName;
> +  UINTN   Cr0;
> +  UINTN   Cr3;
> +  UINTN   Cr4;
> 
>    //
>    // Set current RIP address
> @@ -634,12 +684,29 @@ DumpStackTrace (
>    //
>    *UnwoundStacksCount = 1;
> 
> +  //
> +  // Get system control registers
> +  //
> +  Cr0 = SystemContext.SystemContextX64->Cr0;
> +  Cr3 = SystemContext.SystemContextX64->Cr3;
> +  Cr4 = SystemContext.SystemContextX64->Cr4;
> +
>    //
>    // Print out back trace
>    //
>    InternalPrintMessage ("\nCall trace:\n");
> 
>    for (;;) {
> +    //
> +    // Check for valid frame pointer
> +    //
> +    if (!IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)Rbp + 8) ||
> +        !IsLinearAddressValid (Cr0, Cr3, Cr4, (UINTN)Rbp)) {
> +      InternalPrintMessage ("%a: attempted to dereference an invalid frame "
> +                            "pointer at 0x%016lx\n", __FUNCTION__,
> Rbp);
> +      break;
> +    }
> +
>      //
>      // Print stack frame in the following format:
>      //
> @@ -727,5 +794,5 @@ DumpImageAndCpuContent (
>    //
>    // Dump stack contents
>    //
> -  DumpStackContents (SystemContext.SystemContextX64->Rsp,
> UnwoundStacksCount);
> +  DumpStackContents (SystemContext, UnwoundStacksCount);
>  }
> --
> 2.14.3
> 
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel


  parent reply	other threads:[~2018-01-04  1:02 UTC|newest]

Thread overview: 82+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-14 12:47 [RFC 0/1] Stack trace support in X64 exception handling Paulo Alcantara
2017-11-14 12:47 ` [RFC 1/1] UefiCpuPkg/CpuExceptionHandlerLib/X64: Add stack trace support Paulo Alcantara
2017-11-14 14:01   ` Andrew Fish
2017-11-14 14:26     ` 答复: " Fan Jeff
2017-11-14 14:38       ` Andrew Fish
2017-11-14 15:30     ` Paulo Alcantara
2017-11-14 16:51       ` Brian J. Johnson
2017-12-29  3:48   ` [RFC v4 0/6] Stack trace support in X64 exception handling Paulo Alcantara
2017-12-29  4:39     ` [RFC v4 1/6] UefiCpuPkg/CpuExceptionHandlerLib/X64: Add stack trace support Paulo Alcantara
2018-01-03  8:53       ` 答复: " Fan Jeff
2018-01-03 14:51         ` Paulo Alcantara
2017-12-29  4:39     ` [RFC v4 2/6] UefiCpuPkg/CpuExceptionHandlerLib: Export GetPdbFileName() Paulo Alcantara
2017-12-29  4:39     ` [RFC v4 3/6] UefiCpuPkg/CpuExceptionHandlerLib/Ia32: Add stack trace support Paulo Alcantara
2017-12-29  4:39     ` [RFC v4 4/6] UefiCpuPkg/CpuExceptionHandlerLib: Add helper to valid memory addresses Paulo Alcantara
2018-01-03  8:42       ` 答复: " Fan Jeff
2018-01-03 14:45         ` Paulo Alcantara
2018-01-03 16:59       ` Brian J. Johnson
2018-01-04 13:03         ` Paulo Alcantara
2018-01-04  1:36       ` Yao, Jiewen
2018-01-04  1:58         ` Yao, Jiewen
2018-01-04 13:29           ` Paulo Alcantara
2018-01-04 14:35             ` Yao, Jiewen
2018-01-04 15:15               ` Paulo Alcantara
2018-01-04 13:18         ` Paulo Alcantara
2017-12-29  4:39     ` [RFC v4 5/6] UefiCpuPkg/CpuExceptionHandlerLib: Ensure valid frame/stack pointers Paulo Alcantara
2018-01-03  8:45       ` 答复: " Fan Jeff
2018-01-03 14:48         ` Paulo Alcantara
2018-01-04  1:07       ` Yao, Jiewen [this message]
2017-12-29  4:39     ` [RFC v4 6/6] UefiCpuPkg/CpuExceptionHandlerLib: Correctly print IP addresses Paulo Alcantara
2018-01-03  8:46       ` 答复: " Fan Jeff
2018-01-04  0:59     ` [RFC v4 0/6] Stack trace support in X64 exception handling Yao, Jiewen
2018-01-04 13:36       ` Paulo Alcantara
2018-01-15  0:23     ` [RFC v5 0/8] " Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 1/8] UefiCpuPkg/CpuExceptionHandlerLib/X64: Add stack trace support Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 2/8] UefiCpuPkg/CpuExceptionHandlerLib: Export GetPdbFileName() Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 3/8] UefiCpuPkg/CpuExceptionHandlerLib/Ia32: Add stack trace support Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 4/8] UefiCpuPkg/CpuExceptionHandlerLib: Add helper to validate memory addresses Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 5/8] UefiCpuPkg/CpuExceptionHandlerLib: Ensure valid frame/stack pointers Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 6/8] UefiCpuPkg/CpuExceptionHandlerLib: Correctly print IP addresses Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 7/8] UefiCpuPkg/CpuExceptionHandlerLib: Validate memory address ranges Paulo Alcantara
2018-01-15  0:23       ` [RFC v5 8/8] UefiCpuPkg/CpuExceptionHandlerLib: Add early check in DumpStackContents Paulo Alcantara
2018-01-17 12:57       ` [RFC v5 0/8] Stack trace support in X64 exception handling Yao, Jiewen
2018-01-17 22:48         ` Yao, Jiewen
2018-01-19  0:09           ` Paulo Alcantara
2018-01-19  0:02         ` Paulo Alcantara
2018-01-19  0:15           ` Paulo Alcantara
2018-01-29 13:38         ` Paulo Alcantara
2018-01-31  5:56           ` Yao, Jiewen
2018-01-31 19:05             ` Paulo Alcantara
2017-11-14 13:21 ` [RFC 0/1] " Paulo Alcantara
2017-11-14 14:03   ` 答复: " Fan Jeff
2017-11-14 14:12     ` 答复: " Fan Jeff
2017-11-14 15:37     ` Paulo Alcantara
2017-11-14 16:33       ` Brian J. Johnson
2017-11-14 17:23         ` Andrew Fish
2017-11-14 17:41           ` Brian J. Johnson
2017-11-14 17:56             ` Paulo Alcantara
2017-11-15 13:21       ` 答复: 答复: " Fan Jeff
2017-11-15 14:41         ` Paulo Alcantara
2017-11-15 14:52           ` 答复: " Fan Jeff
2017-11-16  1:18 ` [RFC v2 0/3] " Paulo Alcantara
2017-11-16  1:18   ` [RFC v2 1/3] UefiCpuPkg/CpuExceptionHandlerLib/X64: Add stack trace support Paulo Alcantara
2017-11-16  1:57     ` Yao, Jiewen
2017-11-16 22:13       ` Paulo Alcantara
2017-11-17  3:43         ` Yao, Jiewen
2017-11-20 14:51           ` Paulo Alcantara
2017-11-16 15:43     ` Brian J. Johnson
2017-11-16 22:19       ` Paulo Alcantara
2017-11-16  1:18   ` [RFC v2 2/3] UefiCpuPkg/CpuExceptionHandlerLib: Export GetPdbFileName() Paulo Alcantara
2017-11-16  1:18   ` [RFC v2 3/3] UefiCpuPkg/CpuExceptionHandlerLib/Ia32: Add stack trace support Paulo Alcantara
2017-11-16  1:46   ` [RFC v2 0/3] Stack trace support in X64 exception handling Paulo Alcantara
2017-11-16  5:01     ` Andrew Fish
2017-11-16 22:02       ` Paulo Alcantara
2017-11-16 21:56   ` [RFC v3 " Paulo Alcantara
2017-11-16 21:56     ` [RFC v3 1/3] UefiCpuPkg/CpuExceptionHandlerLib/X64: Add stack trace support Paulo Alcantara
2017-11-17  7:24       ` 答复: " Fan Jeff
2017-11-20 14:59         ` Paulo Alcantara
2017-11-23 14:27           ` 答复: " Fan Jeff
2017-11-23 18:34             ` Andrew Fish
2017-11-23 19:49               ` Fan Jeff
2017-11-16 21:56     ` [RFC v3 2/3] UefiCpuPkg/CpuExceptionHandlerLib: Export GetPdbFileName() Paulo Alcantara
2017-11-16 21:56     ` [RFC v3 3/3] UefiCpuPkg/CpuExceptionHandlerLib/Ia32: Add stack trace support Paulo Alcantara

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