The patch titled
Subject: kmod: make __request_module() killable
has been added to the -mm tree. Its filename is
kmod-make-__request_module-killable.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: kmod: make __request_module() killable
As Tetsuo Handa pointed out, request_module() can stress the system while
the oom-killed caller sleeps in TASK_UNINTERRUPTIBLE.
Make __request_module() killable. The only necessary change is that
call_modprobe() should kmalloc argv and module_name, they can't live in
the stack if we use UMH_KILLABLE. This memory is freed via
call_usermodehelper_freeinfo()->cleanup.
Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kmod.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff -puN kernel/kmod.c~kmod-make-__request_module-killable kernel/kmod.c
--- a/kernel/kmod.c~kmod-make-__request_module-killable
+++ a/kernel/kmod.c
@@ -60,6 +60,12 @@ static DECLARE_RWSEM(umhelper_sem);
*/
char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
+static void free_modprobe_argv(struct subprocess_info *info)
+{
+ kfree(info->argv[3]); /* check call_modprobe() */
+ kfree(info->argv);
+}
+
static int call_modprobe(char *module_name, int wait)
{
static char *envp[] = {
@@ -69,10 +75,26 @@ static int call_modprobe(char *module_na
NULL
};
- char *argv[] = { modprobe_path, "-q", "--", module_name, NULL };
+ char **argv = kmalloc(sizeof(char *[5]), GFP_KERNEL);
+ if (!argv)
+ goto out;
+
+ module_name = kstrdup(module_name, GFP_KERNEL);
+ if (!module_name)
+ goto free_argv;
+
+ argv[0] = modprobe_path;
+ argv[1] = "-q";
+ argv[2] = "--";
+ argv[3] = module_name; /* check free_modprobe_argv() */
+ argv[4] = NULL;
return call_usermodehelper_fns(modprobe_path, argv, envp,
- wait, NULL, NULL, NULL);
+ wait | UMH_KILLABLE, NULL, free_modprobe_argv, NULL);
+free_argv:
+ kfree(argv);
+out:
+ return -ENOMEM;
}
/**
_
Subject: Subject: kmod: make __request_module() killable
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
linux-next.patch
arm-use-set_current_blocked-and-block_sigmask.patch
avr32-dont-mask-signals-in-the-error-path.patch
avr32-use-set_current_blocked-in-handle_signal-sys_rt_sigreturn.patch
avr32-use-block_sigmask.patch
powerpc-use-set_current_blocked-and-block_sigmask.patch
hexagon-use-set_current_blocked-and-block_sigmask.patch
tile-use-set_current_blocked-and-block_sigmask.patch
ia64-use-set_current_blocked-and-block_sigmask.patch
microblaze-dont-reimplement-force_sigsegv.patch
microblaze-no-need-to-reset-handler-if-sa_oneshot.patch
microblaze-fix-signal-masking.patch
microblaze-use-set_current_blocked-and-block_sigmask.patch
mips-use-set_current_blocked-and-block_sigmask.patch
score-dont-mask-signals-if-we-fail-to-setup-signal-stack.patch
score-use-set_current_blocked-and-block_sigmask.patch
unicore32-use-block_sigmask.patch
blackfin-use-set_current_blocked-and-block_sigmask.patch
openrisc-dont-reimplement-force_sigsegv.patch
openrisc-no-need-to-reset-handler-if-sa_oneshot.patch
openrisc-dont-mask-signals-if-we-fail-to-setup-signal-stack.patch
openrisc-use-set_current_blocked-and-block_sigmask.patch
parisc-use-set_current_blocked-and-block_sigmask.patch
s390-use-block_sigmask.patch
xtensa-dont-reimplement-force_sigsegv.patch
xtensa-no-need-to-reset-handler-if-sa_oneshot.patch
xtensa-dont-mask-signals-if-we-fail-to-setup-signal-stack.patch
xtensa-use-set_current_blocked-and-block_sigmask.patch
sparc-use-block_sigmask.patch
frv-use-set_current_blocked-and-block_sigmask.patch
sh-no-need-to-reset-handler-if-sa_oneshot.patch
sh-use-set_current_blocked-and-block_sigmask.patch
h8300-use-set_current_blocked-and-block_sigmask.patch
alpha-use-set_current_blocked-and-block_sigmask.patch
m32r-use-set_current_blocked-and-block_sigmask.patch
m68k-use-set_current_blocked-and-block_sigmask.patch
mn10300-use-set_current_blocked-and-block_sigmask.patch
c6x-use-set_current_blocked-and-block_sigmask.patch
cris-use-set_current_blocked-and-block_sigmask.patch
um-dont-restore-current-blocked-on-error.patch
um-use-set_current_blocked-and-block_sigmask.patch
prctl-add-pr_setget_child_subreaper-to-allow-simple-process-supervision.patch
prctl-add-pr_setget_child_subreaper-to-allow-simple-process-supervision-fix.patch
prctl-add-pr_setget_child_subreaper-to-allow-simple-process-supervision-fix-fix.patch
kernel-exitc-if-init-dies-log-a-signal-which-killed-it-if-any.patch
kernel-exitc-if-init-dies-log-a-signal-which-killed-it-if-any-fix.patch
signal-give-send_sig_forced-more-power-to-beat-signal_unkillable.patch
signal-cosmetic-s-from_ancestor_ns-force-in-prepare_signal-paths.patch
signal-oom_kill_task-use-send_sig_forced-instead-of-force_sig.patch
signal-zap_pid_ns_processes-s-send_sig_noinfo-send_sig_forced.patch
usermodehelper-use-umh_wait_proc-consistently.patch
usermodehelper-introduce-umh_completesub_info.patch
usermodehelper-implement-umh_killable.patch
usermodehelper-kill-umh_wait-renumber-umh_-constants.patch
usermodehelper-____call_usermodehelper-doesnt-need-do_exit.patch
kmod-introduce-call_modprobe-helper.patch
kmod-make-__request_module-killable.patch
pidns-add-reboot_pid_ns-to-handle-the-reboot-syscall.patch
pidns-add-reboot_pid_ns-to-handle-the-reboot-syscall-fix.patch
sysctl-make-kernelns_last_pid-control-being-checkpoint_restore-dependent.patch
fs-proc-introduce-proc-pid-task-tid-children-entry-v9.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
