From e4bc33245124db69b74a6d853ac76c2976f472d5 Mon Sep 17 00:00:00 2001 From: Chen Hanxiao Date: Wed, 15 Apr 2015 16:16:30 -0700 Subject: /proc/PID/status: show all sets of pid according to ns If some issues occurred inside a container guest, host user could not know which process is in trouble just by guest pid: the users of container guest only knew the pid inside containers. This will bring obstacle for trouble shooting. This patch adds four fields: NStgid, NSpid, NSpgid and NSsid: a) In init_pid_ns, nothing changed; b) In one pidns, will tell the pid inside containers: NStgid: 21776 5 1 NSpid: 21776 5 1 NSpgid: 21776 5 1 NSsid: 21729 1 0 ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2. c) If pidns is nested, it depends on which pidns are you in. NStgid: 5 1 NSpid: 5 1 NSpgid: 5 1 NSsid: 1 0 ** Views from level 1 [akpm@linux-foundation.org: add CONFIG_PID_NS ifdef] Signed-off-by: Chen Hanxiao Acked-by: Serge Hallyn Acked-by: "Eric W. Biederman" Tested-by: Serge Hallyn Tested-by: Nathan Scott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/array.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'fs/proc/array.c') diff --git a/fs/proc/array.c b/fs/proc/array.c index 1295a00ca316..a4490c0a4644 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -188,6 +188,24 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, from_kgid_munged(user_ns, GROUP_AT(group_info, g))); put_cred(cred); +#ifdef CONFIG_PID_NS + seq_puts(m, "\nNStgid:"); + for (g = ns->level; g <= pid->level; g++) + seq_printf(m, "\t%d", + task_tgid_nr_ns(p, pid->numbers[g].ns)); + seq_puts(m, "\nNSpid:"); + for (g = ns->level; g <= pid->level; g++) + seq_printf(m, "\t%d", + task_pid_nr_ns(p, pid->numbers[g].ns)); + seq_puts(m, "\nNSpgid:"); + for (g = ns->level; g <= pid->level; g++) + seq_printf(m, "\t%d", + task_pgrp_nr_ns(p, pid->numbers[g].ns)); + seq_puts(m, "\nNSsid:"); + for (g = ns->level; g <= pid->level; g++) + seq_printf(m, "\t%d", + task_session_nr_ns(p, pid->numbers[g].ns)); +#endif seq_putc(m, '\n'); } -- cgit v1.2.2 From 41416f2330112d29f2cfa337bfc7e672bf0c2768 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Wed, 15 Apr 2015 16:17:28 -0700 Subject: lib/string_helpers.c: change semantics of string_escape_mem The current semantics of string_escape_mem are inadequate for one of its current users, vsnprintf(). If that is to honour its contract, it must know how much space would be needed for the entire escaped buffer, and string_escape_mem provides no way of obtaining that (short of allocating a large enough buffer (~4 times input string) to let it play with, and that's definitely a big no-no inside vsnprintf). So change the semantics for string_escape_mem to be more snprintf-like: Return the size of the output that would be generated if the destination buffer was big enough, but of course still only write to the part of dst it is allowed to, and (contrary to snprintf) don't do '\0'-termination. It is then up to the caller to detect whether output was truncated and to append a '\0' if desired. Also, we must output partial escape sequences, otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever they previously contained. This also fixes a bug in the escaped_string() helper function, which used to unconditionally pass a length of "end-buf" to string_escape_mem(); since the latter doesn't check osz for being insanely large, it would happily write to dst. For example, kasprintf(GFP_KERNEL, "something and then %pE", ...); is an easy way to trigger an oops. In test-string_helpers.c, the -ENOMEM test is replaced with testing for getting the expected return value even if the buffer is too small. We also ensure that nothing is written (by relying on a NULL pointer deref) if the output size is 0 by passing NULL - this has to work for kasprintf("%pE") to work. In net/sunrpc/cache.c, I think qword_add still has the same semantics. Someone should definitely double-check this. In fs/proc/array.c, I made the minimum possible change, but longer-term it should stop poking around in seq_file internals. [andriy.shevchenko@linux.intel.com: simplify qword_add] [andriy.shevchenko@linux.intel.com: add missed curly braces] Signed-off-by: Rasmus Villemoes Acked-by: Andy Shevchenko Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/array.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/proc/array.c') diff --git a/fs/proc/array.c b/fs/proc/array.c index a4490c0a4644..13f047ad08e4 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -99,8 +99,8 @@ static inline void task_name(struct seq_file *m, struct task_struct *p) buf = m->buf + m->count; /* Ignore error for now */ - string_escape_str(tcomm, &buf, m->size - m->count, - ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); + buf += string_escape_str(tcomm, buf, m->size - m->count, + ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); m->count = buf - m->buf; seq_putc(m, '\n'); -- cgit v1.2.2 From 25ce319167b517a913a2ba9fc80da8330dbc3249 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 15 Apr 2015 16:18:17 -0700 Subject: proc: remove use of seq_printf return value The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Signed-off-by: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/array.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/proc/array.c') diff --git a/fs/proc/array.c b/fs/proc/array.c index 13f047ad08e4..fd02a9ebfc30 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -632,7 +632,9 @@ static int children_seq_show(struct seq_file *seq, void *v) pid_t pid; pid = pid_nr_ns(v, inode->i_sb->s_fs_info); - return seq_printf(seq, "%d ", pid); + seq_printf(seq, "%d ", pid); + + return 0; } static void *children_seq_start(struct seq_file *seq, loff_t *pos) -- cgit v1.2.2