Subject: + exec-kill-bprm-tcomm-simplify-the-basename-logic.patch added to -mm tree
To: oleg@xxxxxxxxxx,heiko.carstens@xxxxxxxxxx,rostedt@xxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 26 Mar 2014 15:40:29 -0700
The patch titled
Subject: exec: kill bprm->tcomm[], simplify the "basename" logic
has been added to the -mm tree. Its filename is
exec-kill-bprm-tcomm-simplify-the-basename-logic.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/exec-kill-bprm-tcomm-simplify-the-basename-logic.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/exec-kill-bprm-tcomm-simplify-the-basename-logic.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: exec: kill bprm->tcomm[], simplify the "basename" logic
Starting from c4ad8f98bef7 ("execve: use 'struct filename *' for
executable name passing") bprm->filename can not go away after
flush_old_exec(), so we do not need to save the binary name in
bprm->tcomm[] added by 96e02d158678 ("exec: fix use-after-free bug in
setup_new_exec()").
And there was never need for filename_to_taskname-like code, we can simply
do set_task_comm(kbasename(filename).
This patch has to change set_task_comm() and trace_task_rename() to accept
"const char *", but I think this change is also good.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 21 ++-------------------
include/linux/binfmts.h | 1 -
include/linux/sched.h | 2 +-
include/trace/events/task.h | 2 +-
4 files changed, 4 insertions(+), 22 deletions(-)
diff -puN fs/exec.c~exec-kill-bprm-tcomm-simplify-the-basename-logic fs/exec.c
--- a/fs/exec.c~exec-kill-bprm-tcomm-simplify-the-basename-logic
+++ a/fs/exec.c
@@ -1046,7 +1046,7 @@ EXPORT_SYMBOL_GPL(get_task_comm);
* so that a new one can be started
*/
-void set_task_comm(struct task_struct *tsk, char *buf)
+void set_task_comm(struct task_struct *tsk, const char *buf)
{
task_lock(tsk);
trace_task_rename(tsk, buf);
@@ -1055,21 +1055,6 @@ void set_task_comm(struct task_struct *t
perf_event_comm(tsk);
}
-static void filename_to_taskname(char *tcomm, const char *fn, unsigned int len)
-{
- int i, ch;
-
- /* Copies the binary name from after last slash */
- for (i = 0; (ch = *(fn++)) != '\0';) {
- if (ch == '/')
- i = 0; /* overwrite what we wrote */
- else
- if (i < len - 1)
- tcomm[i++] = ch;
- }
- tcomm[i] = '\0';
-}
-
int flush_old_exec(struct linux_binprm * bprm)
{
int retval;
@@ -1083,8 +1068,6 @@ int flush_old_exec(struct linux_binprm *
goto out;
set_mm_exe_file(bprm->mm, bprm->file);
-
- filename_to_taskname(bprm->tcomm, bprm->filename, sizeof(bprm->tcomm));
/*
* Release all of the old mmap stuff
*/
@@ -1127,7 +1110,7 @@ void setup_new_exec(struct linux_binprm
else
set_dumpable(current->mm, suid_dumpable);
- set_task_comm(current, bprm->tcomm);
+ set_task_comm(current, kbasename(bprm->filename));
/* Set the new mm task size. We have to do that late because it may
* depend on TIF_32BIT which is only updated in flush_thread() on
diff -puN include/linux/binfmts.h~exec-kill-bprm-tcomm-simplify-the-basename-logic include/linux/binfmts.h
--- a/include/linux/binfmts.h~exec-kill-bprm-tcomm-simplify-the-basename-logic
+++ a/include/linux/binfmts.h
@@ -44,7 +44,6 @@ struct linux_binprm {
unsigned interp_flags;
unsigned interp_data;
unsigned long loader, exec;
- char tcomm[TASK_COMM_LEN];
};
#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
diff -puN include/linux/sched.h~exec-kill-bprm-tcomm-simplify-the-basename-logic include/linux/sched.h
--- a/include/linux/sched.h~exec-kill-bprm-tcomm-simplify-the-basename-logic
+++ a/include/linux/sched.h
@@ -2325,7 +2325,7 @@ extern long do_fork(unsigned long, unsig
struct task_struct *fork_idle(int);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-extern void set_task_comm(struct task_struct *tsk, char *from);
+extern void set_task_comm(struct task_struct *tsk, const char *from);
extern char *get_task_comm(char *to, struct task_struct *tsk);
#ifdef CONFIG_SMP
diff -puN include/trace/events/task.h~exec-kill-bprm-tcomm-simplify-the-basename-logic include/trace/events/task.h
--- a/include/trace/events/task.h~exec-kill-bprm-tcomm-simplify-the-basename-logic
+++ a/include/trace/events/task.h
@@ -32,7 +32,7 @@ TRACE_EVENT(task_newtask,
TRACE_EVENT(task_rename,
- TP_PROTO(struct task_struct *task, char *comm),
+ TP_PROTO(struct task_struct *task, const char *comm),
TP_ARGS(task, comm),
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
kthread-ensure-locality-of-task_struct-allocations.patch
mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags.patch
mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags-ignore-madv_hugepage-on-s390-to-prevent-sigsegv-in-qemu.patch
mm-thp-add-vm_init_def_mask-and-prctl_thp_disable.patch
exec-kill-the-unnecessary-mm-def_flags-setting-in-load_elf_binary.patch
mm-per-thread-vma-caching.patch
mm-per-thread-vma-caching-fix-4.patch
mm-per-thread-vma-caching-fix-6.patch
mm-per-thread-vma-caching-fix-6-fix.patch
fork-collapse-copy_flags-into-copy_process.patch
mm-mempolicy-rename-slab_node-for-clarity.patch
mm-mempolicy-remove-per-process-flag.patch
res_counter-remove-interface-for-locked-charging-and-uncharging.patch
exit-call-disassociate_ctty-before-exit_task_namespaces.patch
exit-move-check_stack_usage-to-the-end-of-do_exit.patch
exitc-call-proc_exit_connector-after-exit_state-is-set.patch
proc-show-mnt_id-in-proc-pid-fdinfo.patch
exec-kill-bprm-tcomm-simplify-the-basename-logic.patch
wait-fix-reparent_leader-vs-exit_dead-exit_zombie-race.patch
wait-introduce-exit_trace-to-avoid-the-racy-exit_dead-exit_zombie-transition.patch
wait-use-exit_trace-only-if-thread_group_leaderzombie.patch
wait-completely-ignore-the-exit_dead-tasks.patch
wait-swap-exit_zombie-and-exit_dead-to-hide-exit_trace-from-user-space.patch
wait-wstoppedwcontinued-hangs-if-a-zombie-child-is-traced-by-real_parent.patch
wait-wstoppedwcontinued-doesnt-work-if-a-zombie-leader-is-traced-by-another-process.patch
linux-next.patch
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