From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Lei Chen <chenl.lei@gmail.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
gregkh@linuxfoundation.org
Cc: tglx@linutronix.de
Subject: Re: /proc/<pid>/status: incorrect format breaks userland tool
Date: Tue, 22 Jan 2019 00:31:08 -0500 [thread overview]
Message-ID: <20190122053108.GA14185@char.us.oracle.com> (raw)
In-Reply-To: <CAB5AJuWz2NgwixCDh3hr4uv8qECfE2m0q49E_5GfecTnGPuXuQ@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 4743 bytes --]
On Tue, Jan 22, 2019 at 11:29:16AM +0800, Lei Chen wrote:
> Hi Konrad,
Hi,
CC-ing stable,Greg,and LKML. Pls see attached and inline patch and explanation
at bottom.
> I'm running kernel 4.4.153. When running iotop, I got such failure:
> # iotop -P
> Traceback (most recent call last):
> File "/sbin/iotop", line 17, in <module>
> main()
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 620, in main
> main_loop()
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 610, in <lambda>
> main_loop = lambda: run_iotop(options)
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 508, in
> run_iotop
> return curses.wrapper(run_iotop_window, options)
> File "/usr/lib/python2.7/curses/wrapper.py", line 43, in wrapper
> return func(stdscr, *args, **kwds)
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 501, in
> run_iotop_window
> ui.run()
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 155, in run
> self.process_list.duration)
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 434, in
> refresh_display
> lines = self.get_data()
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 415, in get_data
> return list(map(format, processes))
> File "/usr/lib/python2.7/site-packages/iotop/ui.py", line 388, in format
> cmdline = p.get_cmdline()
> File "/usr/lib/python2.7/site-packages/iotop/data.py", line 292, in
> get_cmdline
> proc_status = parse_proc_pid_status(self.pid)
> File "/usr/lib/python2.7/site-packages/iotop/data.py", line 196, in
> parse_proc_pid_status
> key, value = line.split(':\t', 1)
> ValueError: need more than 1 value to unpack
>
> Having a little further debug, I found this error is caused by the
> unexpected blank line in /proc/<pid>/status file, like below:
>
> CapBnd: 0000003fffffffff
> CapAmb: 0000000000000000
>
> Speculation_Store_Bypass: vulnerable
> Cpus_allowed: ff
>
> Checking the git history, I see you touched the line "seq_printf(m,
> "\nSpeculation_Store_Bypass:\t");". Do you think this additional blank line
> is caused by the leading "\n" of "Speculation_Store_Bypass"?
That is correct.
It looks that the backport missed the change. The v4.4 has:
static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
{
#ifdef CONFIG_SECCOMP
seq_printf(m, "Seccomp:\t%d\n", p->seccomp.mode);
#endif
seq_printf(m, "\nSpeculation_Store_Bypass:\t");
Upstream has:
tatic inline void task_seccomp(struct seq_file *m, struct task_struct *p)
{
seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
#ifdef CONFIG_SECCOMP
seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
#endif
seq_printf(m, "\nSpeculation_Store_Bypass:\t");
The af884cd4a5ae6 is the one that removed the '\n' from the end and put it in the
front of 'Seccomp '.
Greg, I am not sure how one would fix this in a stable tree. But the fix is simple
(hadn't tested it..)
From 9e1909f29e1162f2fba190dbab88d1bbcaf0365d Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Tue, 22 Jan 2019 00:27:55 -0500
Subject: [PATCH] Fix: proc: Use underscores for SSBD in 'status'
Upstream af884cd4a5ae6 (not backported) added a '\n' in front
of 'Seccomp' but we have the old format with '\n' at the end.
This causes mayhem with 'Speculation_Store_Bypass' adding an extra
newline breaking tools.
Reported-by:Lei Chen <chenl.lei@gmail.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
fs/proc/array.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/proc/array.c b/fs/proc/array.c
index cb71cbae606d..60cbaa821164 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -333,7 +333,7 @@ static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
#ifdef CONFIG_SECCOMP
seq_printf(m, "Seccomp:\t%d\n", p->seccomp.mode);
#endif
- seq_printf(m, "\nSpeculation_Store_Bypass:\t");
+ seq_printf(m, "Speculation_Store_Bypass:\t");
switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
case -EINVAL:
seq_printf(m, "unknown");
--
2.13.4
>
> Thanks,
> Lei Chen
[-- Attachment #2: 0001-Fix-proc-Use-underscores-for-SSBD-in-status.patch --]
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From 9e1909f29e1162f2fba190dbab88d1bbcaf0365d Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Tue, 22 Jan 2019 00:27:55 -0500
Subject: [PATCH] Fix: proc: Use underscores for SSBD in 'status'
Upstream af884cd4a5ae6 (not backported) added a '\n' in front
of 'Seccomp' but we have the old format with '\n' at the end.
This causes mayhem with 'Speculation_Store_Bypass' adding an extra
newline breaking tools.
Reported-by:Lei Chen <chenl.lei@gmail.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
fs/proc/array.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/proc/array.c b/fs/proc/array.c
index cb71cbae606d..60cbaa821164 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -333,7 +333,7 @@ static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
#ifdef CONFIG_SECCOMP
seq_printf(m, "Seccomp:\t%d\n", p->seccomp.mode);
#endif
- seq_printf(m, "\nSpeculation_Store_Bypass:\t");
+ seq_printf(m, "Speculation_Store_Bypass:\t");
switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
case -EINVAL:
seq_printf(m, "unknown");
--
2.13.4
next parent reply other threads:[~2019-01-22 5:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAB5AJuWz2NgwixCDh3hr4uv8qECfE2m0q49E_5GfecTnGPuXuQ@mail.gmail.com>
2019-01-22 5:31 ` Konrad Rzeszutek Wilk [this message]
2019-01-22 7:10 ` /proc/<pid>/status: incorrect format breaks userland tool Greg KH
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