Re: [PATCH v2 1/1] MdePkg/BaseLib: Fix invalid memory access in AArch64 SetJump/LongJump

["Michael D Kinney" <michael.d.kinney@intel.com>]

No concerns.

Acked-by: Michael D Kinney <michael.d.kinney@intel.com>

Mike

> -----Original Message-----
> From: Ard Biesheuvel <ard.biesheuvel@arm.com>
> Sent: Monday, October 5, 2020 7:33 AM
> To: Jan Bobek <jbobek@nvidia.com>; devel@edk2.groups.io; Kinney, Michael D <michael.d.kinney@intel.com>; Liming Gao
> <gaoliming@byosoft.com.cn>
> Cc: Leif Lindholm <leif@nuviainc.com>; Liu, Zhiguang <zhiguang.liu@intel.com>; Jeff Brasen <jbrasen@nvidia.com>; Ashish Singhal
> <ashishsingha@nvidia.com>
> Subject: Re: [PATCH v2 1/1] MdePkg/BaseLib: Fix invalid memory access in AArch64 SetJump/LongJump
> 
> On 10/1/20 6:15 PM, Jan Bobek wrote:
> > Correct the memory offsets used in REG_ONE/REG_PAIR macros to
> > synchronize them with definition of the BASE_LIBRARY_JUMP_BUFFER
> > structure on AArch64.
> >
> > The REG_ONE macro declares only a single 64-bit register be
> > read/written; however, the subsequent offset is 16 bytes larger,
> > creating an unused memory gap in the middle of the structure and
> > causing SetJump/LongJump functions to read/write 8 bytes of memory
> > past the end of the jump buffer struct.
> >
> > Signed-off-by: Jan Bobek <jbobek@nvidia.com>
> 
> Thanks Jan,
> 
> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
> 
> Liming, Michael: any concerns?
> 
> Thanks,
> 
> 
> > ---
> >   MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.S   | 8 ++++----
> >   MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.asm | 8 ++++----
> >   2 files changed, 8 insertions(+), 8 deletions(-)
> >
> > diff --git a/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.S b/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.S
> > index 72cea259e913..deefdf526b95 100644
> > --- a/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.S
> > +++ b/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.S
> > @@ -20,10 +20,10 @@ GCC_ASM_EXPORT(InternalLongJump)
> >           REG_ONE  (x16,      96) /*IP0*/
> >
> >   #define FPR_LAYOUT                      \
> > -        REG_PAIR ( d8,  d9, 112);       \
> > -        REG_PAIR (d10, d11, 128);       \
> > -        REG_PAIR (d12, d13, 144);       \
> > -        REG_PAIR (d14, d15, 160);
> > +        REG_PAIR ( d8,  d9, 104);       \
> > +        REG_PAIR (d10, d11, 120);       \
> > +        REG_PAIR (d12, d13, 136);       \
> > +        REG_PAIR (d14, d15, 152);
> >
> >   #/**
> >   #  Saves the current CPU context that can be restored with a call to LongJump() and returns 0.#
> > diff --git a/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.asm b/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.asm
> > index 20dd0f1b850f..df70f298998e 100644
> > --- a/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.asm
> > +++ b/MdePkg/Library/BaseLib/AArch64/SetJumpLongJump.asm
> > @@ -19,10 +19,10 @@
> >           REG_ONE  (x16,      #96) /*IP0*/
> >
> >   #define FPR_LAYOUT                       \
> > -        REG_PAIR ( d8,  d9, #112);       \
> > -        REG_PAIR (d10, d11, #128);       \
> > -        REG_PAIR (d12, d13, #144);       \
> > -        REG_PAIR (d14, d15, #160);
> > +        REG_PAIR ( d8,  d9, #104);       \
> > +        REG_PAIR (d10, d11, #120);       \
> > +        REG_PAIR (d12, d13, #136);       \
> > +        REG_PAIR (d14, d15, #152);
> >
> >   ;/**
> >   ;  Saves the current CPU context that can be restored with a call to LongJump() and returns 0.#
> >