github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-24 06:24:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

powerpc: rtas: use get_user to simplify manage_flash_write

Browse Source 
Drop the local 10-byte buffer. The old code copied at most 9 bytes from
the user buffer, but only the first byte was used to select the RTAS
operation.

Use get_user() to read the command byte instead and compare it directly
with '0' and '1'. Drop the explicit user buffer check, since get_user()
will fail on a NULL pointer and correctly return -EFAULT instead of
-EINVAL. Remove the now-obsolete string constants as well as any
strncmp() and strlen() calls.

Return the original count instead of a potentially capped value, since
the full user write has been consumed once the command is accepted.

Use unsigned int op to better match the manage_flash() interface.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260528201226.1599977-3-thorsten.blum@linux.dev
This commit is contained in:
Thorsten Blum 2026-05-28 22:12:27 +02:00 committed by Madhavan Srinivasan
parent 73dca15a3b
commit c7b7cea42c
1 changed files with 10 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
arch/powerpc/kernel/rtas_flash.c
View File

@ -394,30 +394,23 @@ static ssize_t manage_flash_write(struct file *file, const char __user *buf,
size_t count, loff_t *off)
{
struct rtas_manage_flash_t *const args_buf = &rtas_manage_flash_data;
static const char reject_str[] = "0";
static const char commit_str[] = "1";
char stkbuf[10];
int op;
unsigned int op;
char cmd;
guard(mutex)(&rtas_manage_flash_mutex);
if ((args_buf->status == MANAGE_AUTH) || (count == 0))
return count;
op = -1;
if (buf) {
if (count > 9) count = 9;
if (copy_from_user (stkbuf, buf, count))
return -EFAULT;
if (strncmp(stkbuf, reject_str, strlen(reject_str)) == 0)
op = RTAS_REJECT_TMP_IMG;
else if (strncmp(stkbuf, commit_str, strlen(commit_str)) == 0)
op = RTAS_COMMIT_TMP_IMG;
}
if (op == -1) { /* buf is empty, or contains invalid string */
if (get_user(cmd, buf))
return -EFAULT;
if (cmd == '0')
op = RTAS_REJECT_TMP_IMG;
else if (cmd == '1')
op = RTAS_COMMIT_TMP_IMG;
else
return -EINVAL;
}
manage_flash(args_buf, op);
return count;