https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96191
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:fe1a26429038d7cd17abc53f96a6f3e2639b605f commit r11-2576-gfe1a26429038d7cd17abc53f96a6f3e2639b605f Author: Richard Sandiford <richard.sandif...@arm.com> Date: Wed Aug 5 15:18:36 2020 +0100 aarch64: Clear canary value after stack_protect_test [PR96191] The stack_protect_test patterns were leaving the canary value in the temporary register, meaning that it was often still in registers on return from the function. An attacker might therefore have been able to use it to defeat stack-smash protection for a later function. gcc/ PR target/96191 * config/aarch64/aarch64.md (stack_protect_test_<mode>): Set the CC register directly, instead of a GPR. Replace the original GPR destination with an extra scratch register. Zero out operand 3 after use. (stack_protect_test): Update accordingly. gcc/testsuite/ PR target/96191 * gcc.target/aarch64/stack-protector-1.c: New test. * gcc.target/aarch64/stack-protector-2.c: Likewise.
