Re: [edk2-devel] [PATCH] MdeModulePkg/DxeCore: Consistent DebugImageInfoTable updates

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Marvin
> H?user
> Sent: Monday, August 9, 2021 3:21 PM
> To: Wu, Hao A <hao.a.wu@intel.com>; devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Vitaly Cheptsov
> <vit9696@protonmail.com>
> Subject: Re: [edk2-devel] [PATCH] MdeModulePkg/DxeCore: Consistent
> DebugImageInfoTable updates
> 
> On 09/08/2021 08:52, Wu, Hao A wrote:
> >> -----Original Message-----
> >> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Marvin
> >> H?user
> >> Sent: Monday, August 9, 2021 2:16 PM
> >> To: Wu, Hao A <hao.a.wu@intel.com>; devel@edk2.groups.io
> >> Cc: Wang, Jian J <jian.j.wang@intel.com>; Vitaly Cheptsov
> >> <vit9696@protonmail.com>
> >> Subject: Re: [edk2-devel] [PATCH] MdeModulePkg/DxeCore: Consistent
> >> DebugImageInfoTable updates
> >>
> >> Good day Hao,
> >>
> >> Sorry for the confusion, and you are (rightfully!) not alone. :( I'll
> >> quote myself from a different patch:
> >>
> >> [...] for some reason, none of the other patch series had indices appended.
> >> I'm sure I can get that fixed shortly, but what to do then, re-send
> >> the entire bulk? I don't want to spam the list, maybe it is smarter
> >> to group them by some overview mail this one time?
> >
> > I would suggest to send a V2 series for all the patches (not only limited to
> MdeModulePkg) you sent.
> 
> Right, I can do that, just many of the patches were actually meant to be single
> and independent. I believe there were two series that somehow did not get
> indexed by the command. I just forced numbering now and it seems to work.
> 
> May it be easier if I re-send only the two series? A few of the individual patches
> actually started review.


I am fine with this.
My intention for asking V2 for all the patches was that doing so I can simply ignore all the V1 patch mails.

Best Regards,
Hao Wu


> 
> Thanks for your suggestions, and sorry again for the disruption!
> 
> Best regards,
> Marvin
> 
> >
> > Please ensure that patches belong to one series are generated by a single 'git
> format-patch' command.
> > I think doing so will add information like '1/n', '2/n', ..., 'n/n' for the patches in
> one series.
> > And you may need to create a cover-letter for one patch series to give a brief
> summary on the purpose of the series as a whole.
> >
> > Also, if you are implementing a new feature or a fix that touches many
> modules, I suggest to file a Bugzilla tracker for it:
> > Feature request:
> > https://bugzilla.tianocore.org/enter_bug.cgi?product=Tianocore%20Featu
> > re%20Requests
> > Bugfix: https://bugzilla.tianocore.org/enter_bug.cgi?product=EDK2
> >
> > Lastly, you may keep the 'Reviewed-by' tags already received by other
> reviewers.
> >
> > Best Regards,
> > Hao Wu
> >
> >
> >> Sorry for the disruption!
> >>
> >> Best regards,
> >> Marvin
> >>
> >> On 09/08/2021 08:10, Wu, Hao A wrote:
> >>> Sorry Marvin Häuser,
> >>>
> >>> Could you help to confirm that below 9 MdeModulePkg related patches
> >>> are
> >> either:
> >>>    * All independent patches
> >>>    * Belong to a patch series that includes all these 9 MdeModulePkg
> >>> related
> >> commits
> >>>    * Belong to several independent patch series
> >>>
> >>> MdePkg/Base.h: Introduce various alignment-related macros
> >>> MdeModulePkg/CoreDxe: Mandatory LoadedImage for
> >> DebugImageInfoTable
> >>> MdeModulePkg/DxeCore: Fix DebugImageInfoTable size report
> >>> MdeModulePkg/DxeCore: Use the correct source for fixed load address
> >>> MdeModulePkg/PiSmmCore: Drop deprecated image profiling commands
> >>> MdeModulePkg/CoreDxe: Drop caller-allocated image buffers
> >>> MdeModulePkg/DxeCore: Drop unnecessary pointer indirection
> >>> MdeModulePkg/PiSmmIpl: Correct fixed load address bounds check
> >>> MdeModulePkg/DxeCore: Consistent DebugImageInfoTable updates
> >>>
> >>> Best Regards,
> >>> Hao Wu
> >>>
> >>>> -----Original Message-----
> >>>> From: Marvin Häuser <mhaeuser@posteo.de>
> >>>> Sent: Monday, August 9, 2021 3:40 AM
> >>>> To: devel@edk2.groups.io
> >>>> Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> >>>> <hao.a.wu@intel.com>; Bi, Dandan <dandan.bi@intel.com>; Liming Gao
> >>>> <gaoliming@byosoft.com.cn>; Vitaly Cheptsov
> >>>> <vit9696@protonmail.com>
> >>>> Subject: [PATCH] MdeModulePkg/DxeCore: Consistent
> >> DebugImageInfoTable
> >>>> updates
> >>>>
> >>>> In theory, modifications to the DebugImageInfoTable may cause
> >> exceptions.
> >>>> If the exception handler parses the table, this can lead to
> >>>> subsequent exceptions if the table state is inconsistent.
> >>>>
> >>>> Ensure the DebugImageInfoTable remains consistent during modifications.
> >>>> This includes:
> >>>> 1) Free the old table only only after the new table has been published.
> >>>> Mitigates use-after-free of the old table.
> >>>> 2) Do not insert an image entry till it is fully initialised.
> >>>> Entries may be inserted in the live range if an entry was deleted previously.
> >>>> Mitigaes the usage of inconsistent entries.
> >>>> 3) Free the old image entry only after the table has been updated
> >>>> with the NULL value. Mitigates use-after-free of the old entry.
> >>>> 4) Set the MODIFIED state before performing any modifications.
> >>>>
> >>>> Cc: Jian J Wang <jian.j.wang@intel.com>
> >>>> Cc: Hao A Wu <hao.a.wu@intel.com>
> >>>> Cc: Dandan Bi <dandan.bi@intel.com>
> >>>> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> >>>> Cc: Vitaly Cheptsov <vit9696@protonmail.com>
> >>>> Signed-off-by: Marvin Häuser <mhaeuser@posteo.de>
> >>>> ---
> >>>>    MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c | 60 +++++++++++--
> >> ----
> >>>> ---
> >>>>    1 file changed, 34 insertions(+), 26 deletions(-)
> >>>>
> >>>> diff --git a/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> >>>> b/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> >>>> index a75d4158280b..7bd970115111 100644
> >>>> --- a/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> >>>> +++ b/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> >>>> @@ -165,10 +165,11 @@ CoreNewDebugImageInfoEntry (
> >>>>      IN  EFI_HANDLE                  ImageHandle   ) {-  EFI_DEBUG_IMAGE_INFO
> >>>> *Table;-  EFI_DEBUG_IMAGE_INFO      *NewTable;-  UINTN
> >> Index;-
> >>>> UINTN                     TableSize;+  EFI_DEBUG_IMAGE_INFO        *Table;+
> >>>> EFI_DEBUG_IMAGE_INFO        *NewTable;+  UINTN                       Index;+
> >>>> UINTN                       TableSize;+  EFI_DEBUG_IMAGE_INFO_NORMAL
> >>>> *NormalImage;    //   // Set the flag indicating that we're in the process of
> >>>> updating the table.@@ -203,14 +204,6 @@
> >> CoreNewDebugImageInfoEntry (
> >>>>        // Copy the old table into the new one     //     CopyMem (NewTable,
> >> Table,
> >>>> TableSize);-    //-    // Free the old table-    //-    CoreFreePool (Table);-    //-
> >>>> // Update the table header-    //-    Table = NewTable;
> >>>> mDebugInfoTableHeader.EfiDebugImageInfoTable = NewTable;     //     //
> >>>> Enlarge the max table entries and set the first empty entry index
> >>>> to@@ -
> >>>> 218,24 +211,34 @@ CoreNewDebugImageInfoEntry (
> >>>>        //     Index             = mMaxTableEntries;     mMaxTableEntries +=
> >>>> EFI_PAGE_SIZE / EFI_DEBUG_TABLE_ENTRY_SIZE;+    //+    // Free the old
> >>>> table+    //+    CoreFreePool (Table);+    //+    // Update the table header+
> >>>> //+    Table = NewTable;   }    //   // Allocate data for new entry   //-
> >>>> Table[Index].NormalImage = AllocateZeroPool (sizeof
> >>>> (EFI_DEBUG_IMAGE_INFO_NORMAL));-  if (Table[Index].NormalImage !=
> >>>> NULL) {+  NormalImage = AllocateZeroPool (sizeof
> >>>> (EFI_DEBUG_IMAGE_INFO_NORMAL));+  if (NormalImage != NULL) {     //
> >>>> // Update the entry     //-    Table[Index].NormalImage->ImageInfoType
> >>>> = (UINT32) ImageInfoType;-    Table[Index].NormalImage-
> >>>>> LoadedImageProtocolInstance = LoadedImage;-
> >>>> Table[Index].NormalImage->ImageHandle                 = ImageHandle;+
> >>>> NormalImage->ImageInfoType               = (UINT32) ImageInfoType;+
> >>>> NormalImage->LoadedImageProtocolInstance = LoadedImage;+
> >>>> NormalImage->ImageHandle                 = ImageHandle;     //-    // Increase
> >> the
> >>>> number of EFI_DEBUG_IMAGE_INFO elements and set the
> >>>> mDebugInfoTable in modified status.+    // Set the mDebugInfoTable in
> >>>> modified status, insert the entry, and+    // increase the number of
> >>>> EFI_DEBUG_IMAGE_INFO elements.     //-
> >>>> mDebugInfoTableHeader.TableSize++;
> >>>> mDebugInfoTableHeader.UpdateStatus |=
> >>>> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;+
> >> Table[Index].NormalImage
> >>>> = NormalImage;+    mDebugInfoTableHeader.TableSize++;   }
> >>>> mDebugInfoTableHeader.UpdateStatus &=
> >>>> ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS; }@@ -253,8 +256,9
> >> @@
> >>>> CoreRemoveDebugImageInfoEntry (
> >>>>      EFI_HANDLE ImageHandle   ) {-  EFI_DEBUG_IMAGE_INFO  *Table;-
> >> UINTN
> >>>> Index;+  EFI_DEBUG_IMAGE_INFO        *Table;+  UINTN
> >> Index;+
> >>>> EFI_DEBUG_IMAGE_INFO_NORMAL *NormalImage;
> >>>> mDebugInfoTableHeader.UpdateStatus |=
> >>>> EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS; @@ -263,16 +267,20
> >> @@
> >>>> CoreRemoveDebugImageInfoEntry (
> >>>>      for (Index = 0; Index < mMaxTableEntries; Index++) {     if
> >>>> (Table[Index].NormalImage != NULL && Table[Index].NormalImage-
> >>>>> ImageHandle == ImageHandle) {       //-      // Found a match. Free up the
> >>>> record, then NULL the pointer to indicate the slot-      // is free.+      //
> >> Found a
> >>>> match. Set the mDebugInfoTable in modified status and NULL the+      //
> >>>> pointer to indicate the slot is free and.       //-      CoreFreePool
> >>>> (Table[Index].NormalImage);+      NormalImage =
> >>>> Table[Index].NormalImage;+      mDebugInfoTableHeader.UpdateStatus
> >> |=
> >>>> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;
> >> Table[Index].NormalImage
> >>>> = NULL;       //-      // Decrease the number of EFI_DEBUG_IMAGE_INFO
> >>>> elements and set the mDebugInfoTable in modified status.+      //
> >> Decrease
> >>>> the number of EFI_DEBUG_IMAGE_INFO elements.       //
> >>>> mDebugInfoTableHeader.TableSize--;-
> >>>> mDebugInfoTableHeader.UpdateStatus |=
> >>>> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;+      //+      // Free up the
> >>>> record.+      //+      CoreFreePool (NormalImage);       break;     }   }--
> >>>> 2.31.1
> >>
> >>
> >>
> >>
> 
> 
> 
> 
>