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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-04-03 09:35:41 +0000 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-04-21 17:49:01 +0100 |
| commit | fb22faf48f6eb518932f24005f8606e5f19a7304 (patch) | |
| tree | 27f03a736850e068ce2537789c41f56601126414 /libgcc | |
| parent | 1d4a3bfa8311a26814d60165b3e850cce850b61a (diff) | |
| download | gcc-fb22faf48f6eb518932f24005f8606e5f19a7304.zip gcc-fb22faf48f6eb518932f24005f8606e5f19a7304.tar.gz gcc-fb22faf48f6eb518932f24005f8606e5f19a7304.tar.bz2 | |
aarch64, libgcc: Fix unwinding from pac-ret to normal frames [PR94514]
With -mbranch-protection=pac-ret the debug info toggles the
signedness state of the return address so the unwinder knows when
the return address needs pointer authentication.
The unwind context flags were not updated according to the dwarf
frame info.
This causes unwinding across frames that were built without pac-ret
to incorrectly authenticate the return address wich corrupts the
return address on a system where PAuth is enabled.
Note: This even affects systems where all code use pac-ret because
unwinding across a signal frame the return address is not signed.
gcc/testsuite/ChangeLog:
PR target/94514
* g++.target/aarch64/pr94514.C: New test.
* gcc.target/aarch64/pr94514.c: New test.
libgcc/ChangeLog:
PR target/94514
* config/aarch64/aarch64-unwind.h (aarch64_frob_update_context):
Update context->flags accroding to the frame state.
Diffstat (limited to 'libgcc')
| -rw-r--r-- | libgcc/ChangeLog | 6 | ||||
| -rw-r--r-- | libgcc/config/aarch64/aarch64-unwind.h | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index d66f76f..da419ff 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,9 @@ +2020-04-21 Szabolcs Nagy <szabolcs.nagy@arm.com> + + PR target/94514 + * config/aarch64/aarch64-unwind.h (aarch64_frob_update_context): + Update context->flags accroding to the frame state. + 2020-04-19 Uroš Bizjak <ubizjak@gmail.com> * config/i386/sfp-exceptions.c (__sfp_handle_exceptions) [__SSE_MATH__]: diff --git a/libgcc/config/aarch64/aarch64-unwind.h b/libgcc/config/aarch64/aarch64-unwind.h index 4c8790b..ed84a96 100644 --- a/libgcc/config/aarch64/aarch64-unwind.h +++ b/libgcc/config/aarch64/aarch64-unwind.h @@ -104,6 +104,8 @@ aarch64_frob_update_context (struct _Unwind_Context *context, if (fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset & 0x1) /* The flag is used for re-authenticating EH handler's address. */ context->flags |= RA_SIGNED_BIT; + else + context->flags &= ~RA_SIGNED_BIT; return; } |