]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
MIPS: math-emu: Correct delay-slot exception propagation
authorMaciej W. Rozycki <macro@linux-mips.org>
Fri, 3 Apr 2015 22:26:56 +0000 (23:26 +0100)
committerRalf Baechle <ralf@linux-mips.org>
Tue, 7 Apr 2015 23:10:09 +0000 (01:10 +0200)
commit9ab4471c9f1b3e986f4d429951492f736c888ff6
tree331efb7e2a03576a9e3da4f596f8237e1d98efe1
parent2d83fea786d7aeb5b3b76bd492d9b3bccc0f823c
MIPS: math-emu: Correct delay-slot exception propagation

Restore EPC at the branch whose delay slot is emulated if the delay-slot
instruction signals.  This is so that code in `fpu_emulator_cop1Handler'
does not see EPC having advanced and mistakenly successfully resume
userland execution from the location at the branch target in that case.
Restoring EPC guarantees an immediate exit from the emulation loop and
if EPC hasn't advanced at all since entering the loop, also issuing the
signal reported by the delay-slot instruction.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9701/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/math-emu/cp1emu.c
arch/mips/math-emu/dsemul.c