Messages in this thread | | | From | Blaisorblade <> | Subject | Re: [PATCH] comments on locking of task->comm | Date | Sat, 21 May 2005 18:23:38 +0200 |
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On Friday 06 May 2005 19:58, Alexander Nyberg wrote: > tor 2005-05-05 klockan 17:03 -0700 skrev Linux Kernel Mailing List: > > tree 125d9d7553c5f6dc6ad030e4c829a5bf71ab3ef5 > > parent 291c4a75ce7632ee5c565359fb875ba0597f76be > > author Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Fri, 06 May > > 2005 06:16:12 -0700 committer Linus Torvalds <torvalds@ppc970.osdl.org> > > Fri, 06 May 2005 06:36:48 -0700 > > > > [PATCH] comments on locking of task->comm > > > > Add some comments about task->comm, to explain what it is near its > > definition and provide some important pointers to its uses. > > > > Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> > > Signed-off-by: Andrew Morton <akpm@osdl.org> > > Signed-off-by: Linus Torvalds <torvalds@osdl.org> > > > > exec.c | 4 +++- > > linux/sched.h | 7 +++++-- > > 2 files changed, 8 insertions(+), 3 deletions(-) > > > > Index: fs/exec.c > > =================================================================== > > --- be0fe48738b481b4b172cc9a98ac799ca79aece2/fs/exec.c (mode:100644 > > sha1:52acff3f44f09b6e841424deddd6599938eeafdf) +++ > > 125d9d7553c5f6dc6ad030e4c829a5bf71ab3ef5/fs/exec.c (mode:100644 > > sha1:e56ee24370255e2ab4df9a3933ec03f0d07a2de3) @@ -869,9 +869,11 @@ int > > flush_old_exec(struct linux_binprm * > > if (current->euid == current->uid && current->egid == current->gid) > > current->mm->dumpable = 1; > > name = bprm->filename; > > + > > + /* Copies the binary name from after last slash */ > > for (i=0; (ch = *(name++)) != '\0';) { > > if (ch == '/') > > - i = 0; > > + i = 0; /* overwrite what we wrote */ > > else > > if (i < (sizeof(tcomm) - 1)) > > tcomm[i++] = ch; > > Index: include/linux/sched.h > > =================================================================== > > --- be0fe48738b481b4b172cc9a98ac799ca79aece2/include/linux/sched.h > > (mode:100644 sha1:5f868a5885811571fdc701037bf7b09b40a746b8) +++ > > 125d9d7553c5f6dc6ad030e4c829a5bf71ab3ef5/include/linux/sched.h > > (mode:100644 sha1:4dbb109022f3646ff39b7f64464bebb0200071fc) @@ -578,7 > > +578,7 @@ struct task_struct { > > unsigned long flags; /* per process flags, defined below */ > > unsigned long ptrace; > > > > - int lock_depth; /* Lock depth */ > > + int lock_depth; /* BKL lock depth */ > > > > int prio, static_prio; > > struct list_head run_list; > > @@ -661,7 +661,10 @@ struct task_struct { > > struct key *thread_keyring; /* keyring private to this thread */ > > #endif > > int oomkilladj; /* OOM kill score adjustment (bit shift). */ > > - char comm[TASK_COMM_LEN]; > > + char comm[TASK_COMM_LEN]; /* executable name excluding path > > + - access with [gs]et_task_comm (which lock > > + it with task_lock()) > > + - initialized normally by flush_old_exec */ > > 1) comm is not necessarily the executable name, with sys_prctl => > PR_SET_NAME you can change the name arbitrarily Ok, this can be added in the comment... however that's to give a meaning to it... > 2) cbrowser shows alot of acccesses directly to ->comm, mostly under > current->comm but a few that touch other processes. So this locking > comment isn't really valid but may even confuse people. Well, it's reverse-mapped from the comment about task_lock()... possibly those users don't care or > I really do value comments but I'm not sure about these.
Sorry for not answering promptly, I was busy and overlooked that you mailed me privately (I thought you cc'ed LKML and that nobody really cared, and after I forgot about this). -- Paolo Giarrusso, aka Blaisorblade Skype user "PaoloGiarrusso" Linux registered user n. 292729 http://www.user-mode-linux.org/~blaisorblade
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