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Subject[PATCH] arch-powerpc: Return false instead of -EFAULT
Date
Returning a negative value for a boolean function seem to have the
undesired effect of returning true. Replace -EINVAL by false in a
bool-returning function.

The diff of the .s file before and after the change (using cross
compilation) starts with:

440,441c440,441
< .L43:
< li 3,1 # D.25775,
---
> .L42:
> li 3,0 # D.25775,
...

while if -EFAULT is replaced by true, the diff is empty.

There is only one call site, and it expects a boolean value:
arch/powerpc/kernel/ftrace.c:129:
if (!is_module_trampoline(tramp)) {
pr_err("Not a trampoline\n");
return -EINVAL;
}

This issue was found by the following Coccinelle semantic patch:
<smpl>
@@
identifier f;
constant C;
typedef bool;
@@
bool f (...){
<+...
* return -C;
...+>
}
</smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
---
arch/powerpc/kernel/module_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 6838451..a94a5f1 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -160,7 +160,7 @@ bool is_module_trampoline(u32 *p)
BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask));

if (probe_kernel_read(insns, p, sizeof(insns)))
- return -EFAULT;
+ return false;

for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) {
u32 insna = insns[i];
--
2.1.0


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