diff options
| author | Maciej W. Rozycki <macro@imgtec.com> | 2017-06-16 00:07:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-27 15:08:04 -0700 |
| commit | 040078ad0fe82beff150dfd3b060a2ba7b47ea37 (patch) | |
| tree | 5547649758ba6c203d8320dfdd3bd253620c0b9a /arch | |
| parent | 434c9f2e3b4667859a705b48d53f23f5f629ecf1 (diff) | |
MIPS: Fix unaligned PC interpretation in `compute_return_epc'
commit 11a3799dbeb620bf0400b1fda5cc2c6bea55f20a upstream.
Fix a regression introduced with commit fb6883e5809c ("MIPS: microMIPS:
Support handling of delay slots.") and defer to `__compute_return_epc'
if the ISA bit is set in EPC with non-MIPS16, non-microMIPS hardware,
which will then arrange for a SIGBUS due to an unaligned instruction
reference. Returning EPC here is never correct as the API defines this
function's result to be either a negative error code on failure or one
of 0 and BRANCH_LIKELY_TAKEN on success.
Fixes: fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.")
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16395/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/branch.h | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/mips/include/asm/branch.h b/arch/mips/include/asm/branch.h index de781cf54bc7..da80878f2c0d 100644 --- a/arch/mips/include/asm/branch.h +++ b/arch/mips/include/asm/branch.h @@ -74,10 +74,7 @@ static inline int compute_return_epc(struct pt_regs *regs) return __microMIPS_compute_return_epc(regs); if (cpu_has_mips16) return __MIPS16e_compute_return_epc(regs); - return regs->cp0_epc; - } - - if (!delay_slot(regs)) { + } else if (!delay_slot(regs)) { regs->cp0_epc += 4; return 0; } |