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| author | Srinath Parvathaneni <srinath.parvathaneni@arm.com> | 2023-01-23 11:13:18 +0000 |
|---|---|---|
| committer | Srinath Parvathaneni <srinath.parvathaneni@arm.com> | 2023-01-23 11:16:26 +0000 |
| commit | 55a2d8096a799c682922b03bef7c0d4e4c1c8d7b (patch) | |
| tree | b24a2615e7f89c7ca433fa2b63d295b5e1e962be | |
| parent | 273874e925a544d96b8a9999d4c870c1f5191eeb (diff) | |
| download | gcc-55a2d8096a799c682922b03bef7c0d4e4c1c8d7b.zip gcc-55a2d8096a799c682922b03bef7c0d4e4c1c8d7b.tar.gz gcc-55a2d8096a799c682922b03bef7c0d4e4c1c8d7b.tar.bz2 | |
arm: Add support for new frame unwinding instruction "0xb5".
This patch adds support for Arm frame unwinding instruction "0xb5" [1]. When
an exception is taken and "0xb5" instruction is encounter during runtime
stack-unwinding, we use effective vsp as modifier in pointer authentication.
On completion of stack unwinding if "0xb5" instruction is not encountered
then CFA will be used as modifier in pointer authentication.
[1] https://github.com/ARM-software/abi-aa/releases/download/2022Q3/ehabi32.pdf
libgcc/ChangeLog:
2022-11-09 Srinath Parvathaneni <srinath.parvathaneni@arm.com>
* config/arm/pr-support.c (__gnu_unwind_execute): Decode opcode
"0xb5".
| -rw-r--r-- | libgcc/config/arm/pr-support.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/libgcc/config/arm/pr-support.c b/libgcc/config/arm/pr-support.c index abacfb6..9c9d4ee 100644 --- a/libgcc/config/arm/pr-support.c +++ b/libgcc/config/arm/pr-support.c @@ -107,7 +107,9 @@ __gnu_unwind_execute (_Unwind_Context * context, __gnu_unwind_state * uws) _uw op; int set_pc; int set_pac = 0; + int set_pac_sp = 0; _uw reg; + _uw sp; set_pc = 0; for (;;) @@ -124,10 +126,11 @@ __gnu_unwind_execute (_Unwind_Context * context, __gnu_unwind_state * uws) #if defined(TARGET_HAVE_PACBTI) if (set_pac) { - _uw sp; _uw lr; _uw pac; - _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp); + if (!set_pac_sp) + _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, + &sp); _Unwind_VRS_Get (context, _UVRSC_CORE, R_LR, _UVRSD_UINT32, &lr); _Unwind_VRS_Get (context, _UVRSC_PAC, R_IP, _UVRSD_UINT32, &pac); @@ -259,6 +262,14 @@ __gnu_unwind_execute (_Unwind_Context * context, __gnu_unwind_state * uws) continue; } + /* Use current VSP as modifier in PAC validation. */ + if (op == 0xb5) + { + _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp); + set_pac_sp = 1; + continue; + } + if ((op & 0xfc) == 0xb4) /* Obsolete FPA. */ return _URC_FAILURE; |