diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2016-11-07 15:07:02 +0000 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2017-06-17 15:52:13 +0200 |
| commit | efecd43080b438181da8c6e497fa848e49d48226 (patch) | |
| tree | 49c24f220355037479e127b7eb7ffd0ee227ccbe | |
| parent | 8271c67dadb6e64f9ec5c5a8c5ed466a3f8350c1 (diff) | |
MIPS: Clear ISA bit correctly in get_frame_info()
commit ccaf7caf2c73c6db920772bf08bf1d47b2170634 upstream.
get_frame_info() can be called in microMIPS kernels with the ISA bit
already clear. For example this happens when unwind_stack_by_address()
is called because we begin with a PC that has the ISA bit set & subtract
the (odd) offset from the preceding symbol (which does not have the ISA
bit set). Since get_frame_info() unconditionally subtracts 1 from the PC
in microMIPS kernels it incorrectly misaligns the address it then
attempts to access code at, leading to an address error exception.
Fix this by using msk_isa16_mode() to clear the ISA bit, which allows
get_frame_info() to function regardless of whether it is provided with a
PC that has the ISA bit set or not.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14528/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | arch/mips/kernel/process.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index c6a041d9d..11468a029 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -322,17 +322,14 @@ static inline int is_sp_move_ins(union mips_instruction *ip) static int get_frame_info(struct mips_frame_info *info) { -#ifdef CONFIG_CPU_MICROMIPS - union mips_instruction *ip = (void *) (((char *) info->func) - 1); -#else - union mips_instruction *ip = info->func; -#endif + union mips_instruction *ip; unsigned max_insns = info->func_size / sizeof(union mips_instruction); unsigned i; info->pc_offset = -1; info->frame_size = 0; + ip = (void *)msk_isa16_mode((ulong)info->func); if (!ip) goto err; |