* [PATCH] debugfs: Fix debugfs_read_file_str()
@ 2021-05-27 9:11 Dietmar Eggemann
2021-05-29 1:51 ` Steven Rostedt
2021-06-04 8:39 ` Peter Zijlstra
0 siblings, 2 replies; 4+ messages in thread
From: Dietmar Eggemann @ 2021-05-27 9:11 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: Juri Lelli, Vincent Guittot, Steven Rostedt, Greg Kroah-Hartman,
Valentin Schneider, linux-kernel
Read the entire size of the buffer, including the trailing new line
character.
Discovered while reading the sched domain names of CPU0:
before:
cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
SMTMCDIE
after:
cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
SMT
MC
DIE
Fixes: 9af0440ec86eb ("debugfs: Implement debugfs_create_str()")
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
fs/debugfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index e813acfaa6e8..ba7c01cd9a5d 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -893,7 +893,7 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
copy[copy_len] = '\n';
- ret = simple_read_from_buffer(user_buf, count, ppos, copy, copy_len);
+ ret = simple_read_from_buffer(user_buf, count, ppos, copy, len);
kfree(copy);
return ret;
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] debugfs: Fix debugfs_read_file_str()
2021-05-27 9:11 [PATCH] debugfs: Fix debugfs_read_file_str() Dietmar Eggemann
@ 2021-05-29 1:51 ` Steven Rostedt
2021-06-04 8:39 ` Peter Zijlstra
1 sibling, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2021-05-29 1:51 UTC (permalink / raw)
To: Dietmar Eggemann
Cc: Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Greg Kroah-Hartman, Valentin Schneider, linux-kernel
On Thu, 27 May 2021 11:11:05 +0200
Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
> +++ b/fs/debugfs/file.c
> @@ -893,7 +893,7 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
>
> copy[copy_len] = '\n';
>
> - ret = simple_read_from_buffer(user_buf, count, ppos, copy, copy_len);
> + ret = simple_read_from_buffer(user_buf, count, ppos, copy, len);
> kfree(copy);
As we have:
len = strlen(str) + 1;
[..]
copy_len = strscpy(copy, str, len);
I can't think of any situation that len is not equal to copy_len + 1. :-/
Anyway, either "len" or "copy_len + 1" would work.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] debugfs: Fix debugfs_read_file_str()
2021-05-27 9:11 [PATCH] debugfs: Fix debugfs_read_file_str() Dietmar Eggemann
2021-05-29 1:51 ` Steven Rostedt
@ 2021-06-04 8:39 ` Peter Zijlstra
2021-06-04 8:41 ` Greg Kroah-Hartman
1 sibling, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2021-06-04 8:39 UTC (permalink / raw)
To: Dietmar Eggemann
Cc: Ingo Molnar, Juri Lelli, Vincent Guittot, Steven Rostedt,
Greg Kroah-Hartman, Valentin Schneider, linux-kernel
On Thu, May 27, 2021 at 11:11:05AM +0200, Dietmar Eggemann wrote:
> Read the entire size of the buffer, including the trailing new line
> character.
> Discovered while reading the sched domain names of CPU0:
>
> before:
>
> cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
> SMTMCDIE
>
> after:
>
> cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
> SMT
> MC
> DIE
>
> Fixes: 9af0440ec86eb ("debugfs: Implement debugfs_create_str()")
> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Urgh.. so much for last minute changes :/
Greg, AFAICT that commit has since landed in Linus, will you take care
of this?
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] debugfs: Fix debugfs_read_file_str()
2021-06-04 8:39 ` Peter Zijlstra
@ 2021-06-04 8:41 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2021-06-04 8:41 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Dietmar Eggemann, Ingo Molnar, Juri Lelli, Vincent Guittot,
Steven Rostedt, Valentin Schneider, linux-kernel
On Fri, Jun 04, 2021 at 10:39:43AM +0200, Peter Zijlstra wrote:
> On Thu, May 27, 2021 at 11:11:05AM +0200, Dietmar Eggemann wrote:
> > Read the entire size of the buffer, including the trailing new line
> > character.
> > Discovered while reading the sched domain names of CPU0:
> >
> > before:
> >
> > cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
> > SMTMCDIE
> >
> > after:
> >
> > cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
> > SMT
> > MC
> > DIE
> >
> > Fixes: 9af0440ec86eb ("debugfs: Implement debugfs_create_str()")
> > Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
>
> Urgh.. so much for last minute changes :/
>
> Greg, AFAICT that commit has since landed in Linus, will you take care
> of this?
>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Yes, I'll pick it up now, thanks.
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-05-27 9:11 [PATCH] debugfs: Fix debugfs_read_file_str() Dietmar Eggemann
2021-05-29 1:51 ` Steven Rostedt
2021-06-04 8:39 ` Peter Zijlstra
2021-06-04 8:41 ` Greg Kroah-Hartman
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