The patch titled sysctl: convert poweroff_command to proc_rcu_string has been removed from the -mm tree. Its filename was sysctl-convert-poweroff_command-to-proc_rcu_string.patch This patch was dropped because an updated version will be merged The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: sysctl: convert poweroff_command to proc_rcu_string From: Andi Kleen <andi@xxxxxxxxxxxxxx> Avoids races with lockless sysctl. Also saves ~220 bytes in the data segment for default kernels. Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx> Cc: Russell King <rmk+lkml@xxxxxxxxxxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/reboot.h | 2 +- kernel/sys.c | 8 ++++++-- kernel/sysctl.c | 2 +- 3 files changed, 8 insertions(+), 4 deletions(-) diff -puN include/linux/reboot.h~sysctl-convert-poweroff_command-to-proc_rcu_string include/linux/reboot.h --- a/include/linux/reboot.h~sysctl-convert-poweroff_command-to-proc_rcu_string +++ a/include/linux/reboot.h @@ -67,7 +67,7 @@ extern void kernel_power_off(void); void ctrl_alt_del(void); #define POWEROFF_CMD_PATH_LEN 256 -extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN]; +extern char *poweroff_cmd; extern int orderly_poweroff(bool force); diff -puN kernel/sys.c~sysctl-convert-poweroff_command-to-proc_rcu_string kernel/sys.c --- a/kernel/sys.c~sysctl-convert-poweroff_command-to-proc_rcu_string +++ a/kernel/sys.c @@ -1789,7 +1789,7 @@ SYSCALL_DEFINE3(getcpu, unsigned __user return err ? -EFAULT : 0; } -char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; +char *poweroff_cmd = "/sbin/poweroff"; static void argv_cleanup(char **argv, char **envp) { @@ -1806,7 +1806,7 @@ static void argv_cleanup(char **argv, ch int orderly_poweroff(bool force) { int argc; - char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); + char **argv; static char *envp[] = { "HOME=/", "PATH=/sbin:/bin:/usr/sbin:/usr/bin", @@ -1815,6 +1815,10 @@ int orderly_poweroff(bool force) int ret = -ENOMEM; struct subprocess_info *info; + /* RCU protection for poweroff_cmd */ + rcu_read_lock(); + argv = argv_split(GFP_ATOMIC, rcu_dereference(poweroff_cmd), &argc); + rcu_read_unlock(); if (argv == NULL) { printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", __func__, poweroff_cmd); diff -puN kernel/sysctl.c~sysctl-convert-poweroff_command-to-proc_rcu_string kernel/sysctl.c --- a/kernel/sysctl.c~sysctl-convert-poweroff_command-to-proc_rcu_string +++ a/kernel/sysctl.c @@ -886,7 +886,7 @@ static struct ctl_table kern_table[] = { .data = &poweroff_cmd, .maxlen = POWEROFF_CMD_PATH_LEN, .mode = 0644, - .proc_handler = proc_dostring, + .proc_handler = proc_rcu_string, }, #ifdef CONFIG_KEYS { _ Patches currently in -mm which might be from andi@xxxxxxxxxxxxxx are mm-introduce-dump_page-and-print-symbolic-flag-names.patch linux-next.patch hardware-latency-detector-remove-default-m.patch modpost-support-objects-with-more-than-64k-sections.patch tracehooks-kill-some-pt_ptraced-checks.patch tracehooks-check-pt_ptraced-before-reporting-the-single-step.patch ptrace_signal-check-pt_ptraced-before-reporting-a-signal.patch export-__ptrace_detach-and-do_notify_parent_cldstop.patch reorder-the-code-in-kernel-ptracec.patch implement-utrace-ptrace.patch utrace-core.patch sysctl-convert-poweroff_command-to-proc_rcu_string.patch sysctl-convert-hotplug-helper-string-to-proc_rcu_string.patch sysctl-use-rcu-protected-sysctl-for-ocfs-group-add-helper.patch sysctl-fix-up-remaining-references-to-uevent_helper.patch sysctl-fix-up-remaining-references-to-uevent_helper-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html