[PATCH] ARM: traps: fix opcode endianness when read from user memory

From: Taras Kondratiuk
Date: Mon Dec 23 2013 - 11:43:01 EST


Currently code has an inverted logic: opcode from user memory
is swapped to a proper endianness only in case of read error.
While normally opcode should be swapped only if it was read
correctly from user memory.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
Signed-off-by: Taras Kondratiuk <taras.kondratiuk@xxxxxxxxxx>
---
arch/arm/kernel/traps.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 7940241..36a844e 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -425,9 +425,10 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
instr2 = __mem_to_opcode_thumb16(instr2);
instr = __opcode_thumb32_compose(instr, instr2);
}
- } else if (get_user(instr, (u32 __user *)pc)) {
+ } else {
+ if (get_user(instr, (u32 __user *)pc))
+ goto die_sig;
instr = __mem_to_opcode_arm(instr);
- goto die_sig;
}

if (call_undef_hook(regs, instr) == 0)
--
1.7.9.5

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