Yum Rayan wrote:
Attempt to reduce stack usage in time.c (linux-2.6.12-rc1-mm3). Stack
usage was noted using checkstack.pl. Specifically:
Before patch
------------
sys_adjtimex - 128
After patch
-----------
sys_adjtimex - none (register usage only)
Signed-off-by: Yum Rayan <[email protected]>
--- a/kernel/time.c 2005-03-25 22:11:06.000000000 -0800
+++ b/kernel/time.c 2005-03-30 16:59:51.000000000 -0800
@@ -413,17 +413,27 @@
asmlinkage long sys_adjtimex(struct timex __user *txc_p)
{
- struct timex txc; /* Local copy of parameter */
- int ret;
+ struct timex *txc; /* Local copy of parameter */
+ int retval;
+
+ txc = kmalloc(sizeof(struct timex), GFP_KERNEL);
+ if (!txc)
+ return -ENOMEM;
/* Copy the user data space into the kernel copy
* structure. But bear in mind that the structures
* may change
*/
- if(copy_from_user(&txc, txc_p, sizeof(struct timex)))
- return -EFAULT;
- ret = do_adjtimex(&txc);
- return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
+ if(copy_from_user(txc, txc_p, sizeof(struct timex))) {
+ retval = -EFAULT;
+ goto free_txc;
+ }
+ retval = do_adjtimex(txc);
+ if (copy_to_user(txc_p, txc, sizeof(struct timex)))
+ retval = -EFAULT;
+free_txc:
It seems quite unhealthy to add a kmalloc(,GFP_KERNEL) allocation into a
time-sensitive function.
Jeff
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
