diff options
| author | Matt Redfearn <matt.redfearn@imgtec.com> | 2017-08-08 13:22:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-10 07:42:44 -0800 |
| commit | 416ca41754e2d7bfb08ae12b28a4b926f22d7356 (patch) | |
| tree | 502d1efec0a8cb9773e27b1cb886ca07bccb1a33 /arch | |
| parent | de4c175c6359ee791ecdb3a86c760afc286b5e5e (diff) | |
MIPS: microMIPS: Fix decoding of swsp16 instruction
[ Upstream commit cea8cd498f4f1c30ea27e3664b3c671e495c4fce ]
When the immediate encoded in the instruction is accessed, it is sign
extended due to being a signed value being assigned to a signed integer.
The ISA specifies that this operation is an unsigned operation.
The sign extension leads us to incorrectly decode:
801e9c8e: cbf1 sw ra,68(sp)
As having an immediate of 1073741809.
Since the instruction format does not specify signed/unsigned, and this
is currently the only location to use this instuction format, change it
to an unsigned immediate.
Fixes: bb9bc4689b9c ("MIPS: Calculate microMIPS ra properly when unwinding the stack")
Suggested-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Miodrag Dinic <miodrag.dinic@imgtec.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16957/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/uapi/asm/inst.h | 2 | ||||
| -rw-r--r-- | arch/mips/kernel/process.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h index 77429d1622b3..711d9b8465b8 100644 --- a/arch/mips/include/uapi/asm/inst.h +++ b/arch/mips/include/uapi/asm/inst.h @@ -964,7 +964,7 @@ struct mm16_r3_format { /* Load from global pointer format */ struct mm16_r5_format { /* Load/store from stack pointer format */ __BITFIELD_FIELD(unsigned int opcode : 6, __BITFIELD_FIELD(unsigned int rt : 5, - __BITFIELD_FIELD(signed int simmediate : 5, + __BITFIELD_FIELD(unsigned int imm : 5, __BITFIELD_FIELD(unsigned int : 16, /* Ignored */ ;)))) }; diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index ba315e523b33..0211dc737a21 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -212,7 +212,7 @@ static inline int is_ra_save_ins(union mips_instruction *ip, int *poff) if (ip->mm16_r5_format.rt != 31) return 0; - *poff = ip->mm16_r5_format.simmediate; + *poff = ip->mm16_r5_format.imm; *poff = (*poff << 2) / sizeof(ulong); return 1; |