From 23aebe1691a3d98a79676db6c0fd813e16478804 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 7 Apr 2014 15:38:39 -0700 Subject: exec: kill bprm->tcomm[], simplify the "basename" logic Starting from commit 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 Cc: Heiko Carstens Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/exec.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) (limited to 'fs/exec.c') diff --git a/fs/exec.c b/fs/exec.c index b60ccf969a8b..9e81c630dfa7 100644 --- a/fs/exec.c +++ b/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 *tsk, char *buf) 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 * bprm) 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 * bprm) 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 -- cgit v1.2.3