Hello, My take is that unlike in DXE, the UsbHcFreeMemBlock() implementation in PEI phase does not perform freeing the memory.
So I think both the solution: * Provided at https://edk2.groups.io/g/devel/topic/92833071#92165, which aligns with EhciPei * Mentioned at the end of your previous reply, which aligns with XhciDxe should work fine. I will leave it to you for the final decision. Best Regards, Hao Wu > -----Original Message----- > From: He, Jiangang <jiangang...@amd.com> > Sent: Friday, December 16, 2022 12:48 AM > To: Chang, Abner <abner.ch...@amd.com>; Wu, Hao A > <hao.a...@intel.com>; devel@edk2.groups.io > Cc: Lin, Kuei-Hung (Timothy) <kuei-hung....@amd.com>; Ni, Ray > <ray...@intel.com>; Zeng, Star <star.z...@intel.com>; Sun, Zhikai > <zhikai....@intel.com>; Kirkendall, Garrett <garrett.kirkend...@amd.com> > Subject: RE: [PATCH V2] MdeModulePkg/XhciPei: Unlinked XhciPei memory > block > > [AMD Official Use Only - General] > > Yes, it is the same issue discussed in > https://edk2.groups.io/g/devel/topic/92833071#92165 > > MdeModulePkg\Bus\Pci\XhciPei\UsbHcMem.c > > for (Block = Pool->Head->Next; Block != NULL; Block = Pool->Head->Next) { > // UsbHcUnlinkMemBlock (Pool->Head, Block); > UsbHcFreeMemBlock (Pool, Block); > } > Block = Pool->Head->Next never change without calling > UsbHcUnlinkMemBlock (Pool->Head, Block), therefore dead loop. > > Our proposed fix came from dxe version of the equivalent file > MdeModulePkg\Bus\Pci\XhciDxe\UsbHcMem.c but swapped two routine call > order (Now I think it is incorrect as clarified below). > for (Block = Pool->Head->Next; Block != NULL; Block = Pool->Head->Next) { > UsbHcFreeMemBlock (Pool, Block); > UsbHcUnlinkMemBlock (Pool->Head, Block); > } > > https://edk2.groups.io/g/devel/topic/92833071#92165 proposed fix: > > for (Block = Pool->Head->Next; Block != NULL; Block = Block ->Next) { > // UsbHcUnlinkMemBlock (Pool->Head, Block); > UsbHcFreeMemBlock (Pool, Block); > } > > I think it again, both proposals have problem of reading memory content in > the buffer that has just been freed. > > for (Block = Pool->Head->Next; Block != NULL; Block = Pool->Head->Next) { > UsbHcUnlinkMemBlock (Pool->Head, Block); > UsbHcFreeMemBlock (Pool, Block); > } > is right solution and matches dxe version of UsbHcMem.c. > > Thanks, > Jiangang > > -----Original Message----- > From: Chang, Abner <abner.ch...@amd.com> > Sent: Wednesday, December 14, 2022 8:12 PM > To: Wu, Hao A <hao.a...@intel.com>; devel@edk2.groups.io > Cc: Lin, Kuei-Hung (Timothy) <kuei-hung....@amd.com>; Ni, Ray > <ray...@intel.com>; Zeng, Star <star.z...@intel.com>; Sun, Zhikai > <zhikai....@intel.com>; Kirkendall, Garrett <garrett.kirkend...@amd.com>; > He, Jiangang <jiangang...@amd.com> > Subject: RE: [PATCH V2] MdeModulePkg/XhciPei: Unlinked XhciPei memory > block > > [AMD Official Use Only - General] > > Hi Jiangang, > Could you please provide the context of this patch? > > Thanks > Abner > > > -----Original Message----- > > From: Wu, Hao A <hao.a...@intel.com> > > Sent: Monday, December 12, 2022 11:27 AM > > To: Chang, Abner <abner.ch...@amd.com>; devel@edk2.groups.io > > Cc: Lin, Kuei-Hung (Timothy) <kuei-hung....@amd.com>; Ni, Ray > > <ray...@intel.com>; Zeng, Star <star.z...@intel.com>; Sun, Zhikai > > <zhikai....@intel.com>; Kirkendall, Garrett > > <garrett.kirkend...@amd.com> > > Subject: RE: [PATCH V2] MdeModulePkg/XhciPei: Unlinked XhciPei memory > > block > > > > Caution: This message originated from an External Source. Use proper > > caution when opening attachments, clicking links, or responding. > > > > > > Sorry for a question, may I know what issue was met that leads to the > > proposed patch? > > Could you help to check if it is related with the topic discussed in > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fedk2 > > .gr > > > oups.io%2Fg%2Fdevel%2Ftopic%2F92833071%2392165&data=05%7C0 > 1%7 > > > Cabner.chang%40amd.com%7Ccac49c2820e741b8c48a08dadbf0cc24%7C3d > d8 > > > 961fe4884e608e11a82d994e183d%7C0%7C0%7C638064124512265992%7C > Unk > > > nown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6I > k1h > > > aWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=z1Q7NRxN4GMA > %2 > > FBxYd2D7Gnkc3aTD23mRnwNF3H5wE0k%3D&reserved=0? Thanks in > advance. > > > > Best Regards, > > Hao Wu > > > > > -----Original Message----- > > > From: abner.ch...@amd.com <abner.ch...@amd.com> > > > Sent: Saturday, December 10, 2022 11:13 PM > > > To: devel@edk2.groups.io > > > Cc: kuei-hung....@amd.com; Wu, Hao A <hao.a...@intel.com>; Ni, Ray > > > <ray...@intel.com>; Garrett Kirkendall <garrett.kirkend...@amd.com>; > > > Abner Chang <abner.ch...@amd.com> > > > Subject: [PATCH V2] MdeModulePkg/XhciPei: Unlinked XhciPei memory > > > block > > > > > > From: Abner Chang <abner.ch...@amd.com> > > > > > > In V2: Add AMD copyright. > > > > > > Unlink the XhciPei memory block when it has been freed. > > > > > > Signed-off-by: Kuei-Hung Lin <kuei-hung....@amd.com> > > > Cc: Hao A Wu <hao.a...@intel.com> > > > Cc: Ray Ni <ray...@intel.com> > > > Cc: Garrett Kirkendall <garrett.kirkend...@amd.com> > > > Cc: Abner Chang <abner.ch...@amd.com> > > > --- > > > MdeModulePkg/Bus/Pci/XhciPei/UsbHcMem.c | 29 > > > ++++++++++++++++++++++++- > > > 1 file changed, 28 insertions(+), 1 deletion(-) > > > > > > diff --git a/MdeModulePkg/Bus/Pci/XhciPei/UsbHcMem.c > > > b/MdeModulePkg/Bus/Pci/XhciPei/UsbHcMem.c > > > index c64b38fcfc8..39ba31b0913 100644 > > > --- a/MdeModulePkg/Bus/Pci/XhciPei/UsbHcMem.c > > > +++ b/MdeModulePkg/Bus/Pci/XhciPei/UsbHcMem.c > > > @@ -3,6 +3,7 @@ PEIM to produce gPeiUsb2HostControllerPpiGuid > based > > > on gPeiUsbControllerPpiGuid which is used to enable recovery > > > function from USB Drivers. > > > > > > Copyright (c) 2014 - 2016, Intel Corporation. All rights > > > reserved.<BR> > > > +Copyright (C) 2022 Advanced Micro Devices, Inc. All rights > > > +reserved.<BR> > > > > > > SPDX-License-Identifier: BSD-2-Clause-Patent > > > > > > @@ -365,6 +366,32 @@ UsbHcInitMemPool ( > > > return Pool; > > > } > > > > > > +/** > > > + Unlink the memory block from the pool's list. > > > + > > > + @param Head The block list head of the memory's pool. > > > + @param BlockToUnlink The memory block to unlink. > > > + > > > +**/ > > > +VOID > > > +UsbHcUnlinkMemBlock ( > > > + IN USBHC_MEM_BLOCK *Head, > > > + IN USBHC_MEM_BLOCK *BlockToUnlink > > > + ) > > > +{ > > > + USBHC_MEM_BLOCK *Block; > > > + > > > + ASSERT ((Head != NULL) && (BlockToUnlink != NULL)); > > > + > > > + for (Block = Head; Block != NULL; Block = Block->Next) { > > > + if (Block->Next == BlockToUnlink) { > > > + Block->Next = BlockToUnlink->Next; > > > + BlockToUnlink->Next = NULL; > > > + break; > > > + } > > > + } > > > +} > > > + > > > /** > > > Release the memory management pool. > > > > > > @@ -386,8 +413,8 @@ UsbHcFreeMemPool ( > > > // first block. > > > // > > > for (Block = Pool->Head->Next; Block != NULL; Block = > > > Pool->Head->Next) { > > > - // UsbHcUnlinkMemBlock (Pool->Head, Block); > > > UsbHcFreeMemBlock (Pool, Block); > > > + UsbHcUnlinkMemBlock (Pool->Head, Block); > > > } > > > > > > UsbHcFreeMemBlock (Pool, Pool->Head); > > > -- > > > 2.37.1.windows.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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