[PATCH 1/2] ARM: Refactor dump_instr()

From: Zhen Lei
Date: Mon Nov 28 2022 - 06:46:06 EST


1. Rename local variable 'val16' to 'tmp'. So that the processing
statements of thumb and arm can be aligned.
2. Fix two sparse check warnings: (add __user for type conversion)
warning: incorrect type in initializer (different address spaces)
expected unsigned short [noderef] __user *register __p
got unsigned short [usertype] *
3. Prepare for the next patch to avoid repeated judgment.
Before:
if (!user_mode(regs)) {
if (thumb)
else
} else {
if (thumb)
else
}

After:
if (thumb) {
if (user_mode(regs))
else
} else {
if (user_mode(regs))
else
}

Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
KernelVersion: v6.1-rc7
arch/arm/kernel/traps.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 20b2db6dcd1ced7..a92e0763739584e 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -178,19 +178,20 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
for (i = -4; i < 1 + !!thumb; i++) {
unsigned int val, bad;

- if (!user_mode(regs)) {
- if (thumb) {
- u16 val16;
- bad = get_kernel_nofault(val16, &((u16 *)addr)[i]);
- val = val16;
- } else {
- bad = get_kernel_nofault(val, &((u32 *)addr)[i]);
- }
+ if (thumb) {
+ u16 tmp;
+
+ if (user_mode(regs))
+ bad = get_user(tmp, &((u16 __user *)addr)[i]);
+ else
+ bad = get_kernel_nofault(tmp, &((u16 *)addr)[i]);
+
+ val = tmp;
} else {
- if (thumb)
- bad = get_user(val, &((u16 *)addr)[i]);
+ if (user_mode(regs))
+ bad = get_user(val, &((u32 __user *)addr)[i]);
else
- bad = get_user(val, &((u32 *)addr)[i]);
+ bad = get_kernel_nofault(val, &((u32 *)addr)[i]);
}

if (!bad)
--
2.25.1