From 9cc8cbc7f8b7bc3db48bf6d59a731af728e786ce Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 26 Jun 2006 00:25:52 -0700 Subject: [PATCH] simply fix first_tgid Like the bug Oleg spotted in first_tid there was also a small off by one error in first_tgid, when a seek was done on the /proc directory. This fixes that and changes the code structure to make it a little more obvious what is going on. Signed-off-by: Eric W. Biederman Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/base.c b/fs/proc/base.c index 8180579..bbcaef9 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2040,34 +2040,32 @@ out: * In the case of a seek we start with &init_task and walk nr * threads past it. */ -static struct task_struct *first_tgid(int tgid, int nr) +static struct task_struct *first_tgid(int tgid, unsigned int nr) { - struct task_struct *pos = NULL; + struct task_struct *pos; rcu_read_lock(); if (tgid && nr) { pos = find_task_by_pid(tgid); - if (pos && !thread_group_leader(pos)) - pos = NULL; - if (pos) - nr = 0; + if (pos && thread_group_leader(pos)) + goto found; } /* If nr exceeds the number of processes get out quickly */ + pos = NULL; if (nr && nr >= nr_processes()) goto done; /* If we haven't found our starting place yet start with * the init_task and walk nr tasks forward. */ - if (!pos && (nr >= 0)) - pos = next_task(&init_task); - - for (; pos && pid_alive(pos); pos = next_task(pos)) { - if (--nr > 0) - continue; - get_task_struct(pos); - goto done; + for (pos = next_task(&init_task); nr > 0; --nr) { + pos = next_task(pos); + if (pos == &init_task) { + pos = NULL; + goto done; + } } - pos = NULL; +found: + get_task_struct(pos); done: rcu_read_unlock(); return pos; -- cgit v1.1