[PATCH] powerpc/rtas_flash: Move an assignment...

[PATCH] powerpc/rtas_flash: Move an assignment for the variable "rc" in manage_flash_write()

From: SF Markus Elfring <hidden>
Date: 2017-01-19 20:42:27

From: Markus Elfring <redacted>
Date: Thu, 19 Jan 2017 21:20:09 +0100

A local variable was set to an error code before a concrete error situation
was detected. Thus move the corresponding assignment into an if branch
to indicate a software failure there.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <redacted>
---
 arch/powerpc/kernel/rtas_flash.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index db2b482af658..663904beff67 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c

@@ -419,9 +419,10 @@ static ssize_t manage_flash_write(struct file *file, const char __user *buf,
 	op = -1;
 	if (buf) {
 		if (count > 9) count = 9;
-		rc = -EFAULT;
-		if (copy_from_user (stkbuf, buf, count))
+		if (copy_from_user(stkbuf, buf, count)) {
+			rc = -EFAULT;
 			goto error;
+		}
 		if (strncmp(stkbuf, reject_str, strlen(reject_str)) == 0) 
 			op = RTAS_REJECT_TMP_IMG;
 		else if (strncmp(stkbuf, commit_str, strlen(commit_str)) == 0)

-- 
2.11.0

Re: [PATCH] powerpc/rtas_flash: Move an assignment for the variable "rc" in manage_flash_write()

From: Tyrel Datwyler <hidden>
Date: 2017-01-20 00:36:17

On 01/19/2017 12:33 PM, SF Markus Elfring wrote:

quoted hunk

From: Markus Elfring <redacted>
Date: Thu, 19 Jan 2017 21:20:09 +0100

A local variable was set to an error code before a concrete error situation
was detected. Thus move the corresponding assignment into an if branch
to indicate a software failure there.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <redacted>
---
 arch/powerpc/kernel/rtas_flash.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index db2b482af658..663904beff67 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c

@@ -419,9 +419,10 @@ static ssize_t manage_flash_write(struct file *file, const char __user *buf,
 	op = -1;
 	if (buf) {
 		if (count > 9) count = 9;
-		rc = -EFAULT;
-		if (copy_from_user (stkbuf, buf, count))
+		if (copy_from_user(stkbuf, buf, count)) {
+			rc = -EFAULT;
 			goto error;
+		}
 		if (strncmp(stkbuf, reject_str, strlen(reject_str)) == 0) 
 			op = RTAS_REJECT_TMP_IMG;
 		else if (strncmp(stkbuf, commit_str, strlen(commit_str)) == 0)

Taking a closer look at the function in question I see that branching to
the "error" tag on a goto results in the rtas_manage_flash_mutex being
unlocked and the value of rc being returned to the caller.

error:
        mutex_unlock(&rtas_manage_flash_mutex);
        return rc;
}

There are only 2 places in this function that branch to the "error" tag,
and I wonder if it would be cleaner just to get rid of the "rc" variable
altogether and instead unlock the mutex and return the proper -EBADTHING
value at those two branch sites?

-Tyrel

`h`	back out one level
`j`	next message in thread
`k`	previous message in thread
`l`	drill in
`Esc`	close help / fold thread tree
`?`	toggle this help