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| author | Maciej W. Rozycki <macro@imgtec.com> | 2017-06-16 00:07:34 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2017-06-29 02:42:26 +0200 |
| commit | 11a3799dbeb620bf0400b1fda5cc2c6bea55f20a (patch) | |
| tree | e04e3cf3a4a30b7f8bcab14a555bfc8fdfa9d7a8 /arch | |
| parent | a9db101b735a9d49295326ae41f610f6da62b08c (diff) | |
| download | linux-0-day-11a3799dbeb620bf0400b1fda5cc2c6bea55f20a.tar.gz linux-0-day-11a3799dbeb620bf0400b1fda5cc2c6bea55f20a.tar.xz | |
MIPS: Fix unaligned PC interpretation in `compute_return_epc'
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
Cc: stable@vger.kernel.org # 3.9+
Patchwork: https://patchwork.linux-mips.org/patch/16395/
Signed-off-by: Ralf Baechle <ralf@linux-mips.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 de781cf54bc7a..da80878f2c0dc 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; } |