[PATCH] arm64: fix endianness annotation in call_undef_hook()
Luc Van Oostenryck
luc.vanoostenryck at gmail.com
Wed Jun 28 07:55:55 PDT 2017
Here we're reading thumb or ARM instructions, which are always
stored in memory in little-endian order. These values are thus
correctly converted to native order but the intermediate value
should be annotated as for little-endian values.
Fix this by declaring the intermediate var as __le32 or __le16.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck at gmail.com>
---
arch/arm64/kernel/traps.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 0805b44f9..bdf390ae3 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -344,22 +344,24 @@ static int call_undef_hook(struct pt_regs *regs)
if (compat_thumb_mode(regs)) {
/* 16-bit Thumb instruction */
- if (get_user(instr, (u16 __user *)pc))
+ __le16 instr_le;
+ if (get_user(instr_le, (__le16 __user *)pc))
goto exit;
- instr = le16_to_cpu(instr);
+ instr = le16_to_cpu(instr_le);
if (aarch32_insn_is_wide(instr)) {
u32 instr2;
- if (get_user(instr2, (u16 __user *)(pc + 2)))
+ if (get_user(instr_le, (__le16 __user *)(pc + 2)))
goto exit;
- instr2 = le16_to_cpu(instr2);
+ instr2 = le16_to_cpu(instr_le);
instr = (instr << 16) | instr2;
}
} else {
/* 32-bit ARM instruction */
- if (get_user(instr, (u32 __user *)pc))
+ __le32 instr_le;
+ if (get_user(instr_le, (__le32 __user *)pc))
goto exit;
- instr = le32_to_cpu(instr);
+ instr = le32_to_cpu(instr_le);
}
raw_spin_lock_irqsave(&undef_lock, flags);
--
2.13.0
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