Hi Marcelo,
There is a problem with task name handling in the /proc fs. See
http://www.ussg.iu.edu/hypermail/linux/kernel/0407.1/0136.html
for the patch that eventually made its way into the 2.6 tree.
We now have people experiencing the same problem/bug in 2.4. Here
is a patch for 2.4 that implements the same fix. Please consider
applying.
Thanks,
Signed-off-by: Mike Kravetz <[email protected]>
diff -Naur linux-2.4.28-rc2/fs/exec.c linux-2.4.28-rc2.work/fs/exec.c
--- linux-2.4.28-rc2/fs/exec.c 2004-02-18 13:36:31.000000000 +0000
+++ linux-2.4.28-rc2.work/fs/exec.c 2004-11-11 22:51:06.000000000 +0000
@@ -563,12 +563,29 @@
tsk->tgid = tsk->pid;
}
+void get_task_comm(char *buf, struct task_struct *tsk)
+{
+ /* buf must be at least sizeof(tsk->comm) in size */
+ task_lock(tsk);
+ memcpy(buf, tsk->comm, sizeof(tsk->comm));
+ task_unlock(tsk);
+}
+
+void set_task_comm(struct task_struct *tsk, char *buf)
+{
+ task_lock(tsk);
+ strncpy(tsk->comm, buf, sizeof(tsk->comm));
+ tsk->comm[sizeof(tsk->comm)-1]='\0';
+ task_unlock(tsk);
+}
+
int flush_old_exec(struct linux_binprm * bprm)
{
char * name;
int i, ch, retval;
struct signal_struct * oldsig;
struct files_struct * files;
+ char tcomm[sizeof(current->comm)];
/*
* Make sure we have a private signal table
@@ -610,10 +627,11 @@
if (ch == '/')
i = 0;
else
- if (i < 15)
- current->comm[i++] = ch;
+ if (i < (sizeof(tcomm) - 1))
+ tcomm[i++] = ch;
}
- current->comm[i] = '\0';
+ tcomm[i] = '\0';
+ set_task_comm(current, tcomm);
flush_thread();
diff -Naur linux-2.4.28-rc2/fs/proc/array.c linux-2.4.28-rc2.work/fs/proc/array.c
--- linux-2.4.28-rc2/fs/proc/array.c 2003-11-28 18:26:21.000000000 +0000
+++ linux-2.4.28-rc2.work/fs/proc/array.c 2004-11-11 22:57:51.000000000 +0000
@@ -86,10 +86,13 @@
{
int i;
char * name;
+ char tcomm[sizeof(p->comm)];
+
+ get_task_comm(tcomm, p);
ADDBUF(buf, "Name:\t");
- name = p->comm;
- i = sizeof(p->comm);
+ name = tcomm;
+ i = sizeof(tcomm);
do {
unsigned char c = *name;
name++;
@@ -308,6 +311,7 @@
int res;
pid_t ppid;
struct mm_struct *mm;
+ char tcomm[sizeof(task->comm)];
state = *get_task_state(task);
vsize = eip = esp = 0;
@@ -333,6 +337,8 @@
up_read(&mm->mmap_sem);
}
+ get_task_comm(tcomm, task);
+
wchan = get_wchan(task);
collect_sigign_sigcatch(task, &sigign, &sigcatch);
@@ -350,7 +356,7 @@
%lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d\n",
task->pid,
- task->comm,
+ tcomm,
state,
ppid,
task->pgrp,
diff -Naur linux-2.4.28-rc2/include/linux/sched.h linux-2.4.28-rc2.work/include/linux/sched.h
--- linux-2.4.28-rc2/include/linux/sched.h 2004-11-11 20:53:54.000000000 +0000
+++ linux-2.4.28-rc2.work/include/linux/sched.h 2004-11-11 22:59:14.000000000 +0000
@@ -800,6 +800,9 @@
extern int do_execve(char *, char **, char **, struct pt_regs *);
extern int do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long);
+extern void set_task_comm(struct task_struct *tsk, char *from);
+extern void get_task_comm(char *to, struct task_struct *tsk);
+
extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
On Fri, Nov 12, 2004 at 09:31:16AM -0800, Mike Kravetz wrote:
> Hi Marcelo,
>
> There is a problem with task name handling in the /proc fs. See
> http://www.ussg.iu.edu/hypermail/linux/kernel/0407.1/0136.html
> for the patch that eventually made its way into the 2.6 tree.
>
> We now have people experiencing the same problem/bug in 2.4. Here
> is a patch for 2.4 that implements the same fix. Please consider
> applying.
Applied, thanks.
> Thanks,
> Signed-off-by: Mike Kravetz <[email protected]>
>
> diff -Naur linux-2.4.28-rc2/fs/exec.c linux-2.4.28-rc2.work/fs/exec.c
> --- linux-2.4.28-rc2/fs/exec.c 2004-02-18 13:36:31.000000000 +0000
> +++ linux-2.4.28-rc2.work/fs/exec.c 2004-11-11 22:51:06.000000000 +0000
> @@ -563,12 +563,29 @@
> tsk->tgid = tsk->pid;
> }
>
> +void get_task_comm(char *buf, struct task_struct *tsk)
> +{
> + /* buf must be at least sizeof(tsk->comm) in size */
> + task_lock(tsk);
> + memcpy(buf, tsk->comm, sizeof(tsk->comm));
> + task_unlock(tsk);
> +}
> +
> +void set_task_comm(struct task_struct *tsk, char *buf)
> +{
> + task_lock(tsk);
> + strncpy(tsk->comm, buf, sizeof(tsk->comm));
> + tsk->comm[sizeof(tsk->comm)-1]='\0';
> + task_unlock(tsk);
> +}
> +
> int flush_old_exec(struct linux_binprm * bprm)
> {
> char * name;
> int i, ch, retval;
> struct signal_struct * oldsig;
> struct files_struct * files;
> + char tcomm[sizeof(current->comm)];
>
> /*
> * Make sure we have a private signal table
> @@ -610,10 +627,11 @@
> if (ch == '/')
> i = 0;
> else
> - if (i < 15)
> - current->comm[i++] = ch;
> + if (i < (sizeof(tcomm) - 1))
> + tcomm[i++] = ch;
> }
> - current->comm[i] = '\0';
> + tcomm[i] = '\0';
> + set_task_comm(current, tcomm);
>
> flush_thread();
>
> diff -Naur linux-2.4.28-rc2/fs/proc/array.c linux-2.4.28-rc2.work/fs/proc/array.c
> --- linux-2.4.28-rc2/fs/proc/array.c 2003-11-28 18:26:21.000000000 +0000
> +++ linux-2.4.28-rc2.work/fs/proc/array.c 2004-11-11 22:57:51.000000000 +0000
> @@ -86,10 +86,13 @@
> {
> int i;
> char * name;
> + char tcomm[sizeof(p->comm)];
> +
> + get_task_comm(tcomm, p);
>
> ADDBUF(buf, "Name:\t");
> - name = p->comm;
> - i = sizeof(p->comm);
> + name = tcomm;
> + i = sizeof(tcomm);
> do {
> unsigned char c = *name;
> name++;
> @@ -308,6 +311,7 @@
> int res;
> pid_t ppid;
> struct mm_struct *mm;
> + char tcomm[sizeof(task->comm)];
>
> state = *get_task_state(task);
> vsize = eip = esp = 0;
> @@ -333,6 +337,8 @@
> up_read(&mm->mmap_sem);
> }
>
> + get_task_comm(tcomm, task);
> +
> wchan = get_wchan(task);
>
> collect_sigign_sigcatch(task, &sigign, &sigcatch);
> @@ -350,7 +356,7 @@
> %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu \
> %lu %lu %lu %lu %lu %lu %lu %lu %d %d\n",
> task->pid,
> - task->comm,
> + tcomm,
> state,
> ppid,
> task->pgrp,
> diff -Naur linux-2.4.28-rc2/include/linux/sched.h linux-2.4.28-rc2.work/include/linux/sched.h
> --- linux-2.4.28-rc2/include/linux/sched.h 2004-11-11 20:53:54.000000000 +0000
> +++ linux-2.4.28-rc2.work/include/linux/sched.h 2004-11-11 22:59:14.000000000 +0000
> @@ -800,6 +800,9 @@
> extern int do_execve(char *, char **, char **, struct pt_regs *);
> extern int do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long);
>
> +extern void set_task_comm(struct task_struct *tsk, char *from);
> +extern void get_task_comm(char *to, struct task_struct *tsk);
> +
> extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
> extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
> extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));