Hi,
On Tue, 21 Apr 2020 at 18:52, Szabolcs Nagy <szabolcs.n...@arm.com> wrote: > > The 04/17/2020 11:05, Kyrylo Tkachov wrote: > > Hi Szabolcs, > > > > > -----Original Message----- > > > From: Szabolcs Nagy <szabolcs.n...@arm.com> > > > Sent: 09 April 2020 15:20 > > > To: gcc-patches@gcc.gnu.org > > > Cc: Richard Earnshaw <richard.earns...@arm.com>; Richard Sandiford > > > <richard.sandif...@arm.com>; Kyrylo Tkachov <kyrylo.tkac...@arm.com> > > > Subject: [PATCH] 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. > > > > > > > Ok, I'm guessing this needs backporting? > > committed now, > > yes i think it has to go back to gcc-9 and gcc-8, > i will do that later. thanks. The new test fails with ilp32, not sure if that's supposed to work? FAIL: gcc.target/aarch64/pr94514.c (test for excess errors) Excess errors: /gcc/testsuite/gcc.target/aarch64/pr94514.c:27:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] spawn /aci-gcc-fsf/builds/gcc-fsf-gccsrc/tools/aarch64-none-elf/invoke-foundation-v8-bare-metal.sh ./pr94514.exe force_unwind_stop: CFA: 0xefffff80 PC: 0x80001304 actions: 10 force_unwind_stop: CFA: 0xefffff90 PC: 0x8000133c actions: 10 Terminated by exception. *** EXIT code 126 gcc.target/aarch64/pr94514.c execution test (reason: TCL LOOKUP CHANNEL exp7) FAIL: gcc.target/aarch64/pr94514.c execution test (executed using the Foundation Model) The C++ test compiles without warnings, but fails at execution too (without the force_unwind_stop traces): PASS: g++.target/aarch64/pr94514.C (test for excess errors) spawn /aci-gcc-fsf/builds/gcc-fsf-gccsrc/tools/aarch64-none-elf/invoke-foundation-v8-bare-metal.sh ./pr94514.exe Terminated by exception. *** EXIT code 126 g++.target/aarch64/pr94514.C execution test (reason: TCL LOOKUP CHANNEL exp7) FAIL: g++.target/aarch64/pr94514.C execution test Maybe you just want to skip the test for ilp32? Thanks, Christophe
