[PATCH v2] x86/microcode: Silence a static checker warning

From: Dan Carpenter
Date: Thu Aug 24 2017 - 16:16:43 EST


The code here prints an error if "p" is an error pointer but it still
dereferences it at the end of the function when it does:

intel_ucode_patch = (struct microcode_intel *)__pa_nodebug(p->data);

We can just return early instead.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
v2: return early instead checking for IS_ERR_OR_NULL() at the end.

We have to keep the final check whether "p" is NULL to handle the
situation were we set "prev_found = true;" but then hit the continue
statement instead of allocating "p".

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 59edbe9d4ccb..aab900ddea6a 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -184,10 +184,11 @@ static void save_microcode_patch(void *data, unsigned int size)
continue;

p = __alloc_microcode_buf(data, size);
- if (IS_ERR(p))
+ if (IS_ERR(p)) {
pr_err("Error allocating buffer %p\n", data);
- else
- list_replace(&iter->plist, &p->plist);
+ return;
+ }
+ list_replace(&iter->plist, &p->plist);
}
}

@@ -197,10 +198,11 @@ static void save_microcode_patch(void *data, unsigned int size)
*/
if (!prev_found) {
p = __alloc_microcode_buf(data, size);
- if (IS_ERR(p))
+ if (IS_ERR(p)) {
pr_err("Error allocating buffer for %p\n", data);
- else
- list_add_tail(&p->plist, &microcode_cache);
+ return;
+ }
+ list_add_tail(&p->plist, &microcode_cache);
}

/*