From: Al Viro <viro@ZenIV.linux.org.uk>
To: linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>, Oleg Nesterov <oleg@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Christoph Hellwig <hch@lst.de>
Subject: [PATCH 3/8] kernel_wait4()/kernel_waitid(): delay copying status to userland
Date: Mon, 15 May 2017 23:37:11 +0100 [thread overview]
Message-ID: <20170515223716.2085-3-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20170515223716.2085-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
kernel/exit.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index b3c141a4432f..574e6b04f838 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1002,7 +1002,7 @@ struct wait_opts {
struct pid *wo_pid;
struct siginfo __user *wo_info;
- int __user *wo_stat;
+ int wo_stat;
struct rusage *wo_rusage;
wait_queue_t child_wait;
@@ -1189,8 +1189,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
retval = 0;
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
- if (!retval && wo->wo_stat)
- retval = put_user(status, wo->wo_stat);
+ wo->wo_stat = status;
infop = wo->wo_info;
if (!retval && infop)
@@ -1322,8 +1321,7 @@ static int wait_task_stopped(struct wait_opts *wo,
if (wo->wo_rusage)
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
retval = 0;
- if (!retval && wo->wo_stat)
- retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
+ wo->wo_stat = (exit_code << 8) | 0x7f;
infop = wo->wo_info;
if (!retval && infop)
@@ -1383,12 +1381,9 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
if (!wo->wo_info) {
if (wo->wo_rusage)
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
- retval = 0;
put_task_struct(p);
- if (!retval && wo->wo_stat)
- retval = put_user(0xffff, wo->wo_stat);
- if (!retval)
- retval = pid;
+ wo->wo_stat = 0xffff;
+ retval = pid;
} else {
retval = wait_noreap_copyout(wo, p, pid, uid,
CLD_CONTINUED, SIGCONT);
@@ -1662,7 +1657,6 @@ static long kernel_waitid(int which, pid_t upid, struct siginfo __user *infop,
wo.wo_pid = pid;
wo.wo_flags = options;
wo.wo_info = infop;
- wo.wo_stat = NULL;
wo.wo_rusage = ru;
ret = do_wait(&wo);
@@ -1734,10 +1728,12 @@ static long kernel_wait4(pid_t upid, int __user *stat_addr,
wo.wo_pid = pid;
wo.wo_flags = options | WEXITED;
wo.wo_info = NULL;
- wo.wo_stat = stat_addr;
+ wo.wo_stat = 0;
wo.wo_rusage = ru;
ret = do_wait(&wo);
put_pid(pid);
+ if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
+ ret = -EFAULT;
return ret;
}
--
2.11.0
next prev parent reply other threads:[~2017-05-15 22:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 22:31 [RFC][PATCHSET] wait4()/waitid() cleanups Al Viro
2017-05-15 22:37 ` [PATCH 1/8] move compat wait4 and waitid next to native variants Al Viro
2017-05-15 22:37 ` [PATCH 2/8] wait4(2)/waitid(2): separate copying rusage to userland Al Viro
2017-05-15 22:37 ` Al Viro [this message]
2017-05-15 22:37 ` [PATCH 4/8] waitid(2): leave copyout of siginfo to syscall itself Al Viro
2017-05-15 23:06 ` Linus Torvalds
2017-05-15 23:46 ` Al Viro
2017-05-17 19:48 ` Eric W. Biederman
2017-05-15 22:37 ` [PATCH 5/8] lift getrusage() from wait_noreap_copyout() Al Viro
2017-05-15 22:37 ` [PATCH 6/8] kill wait_noreap_copyout() Al Viro
2017-05-15 22:37 ` [PATCH 7/8] wait_task_zombie: consolidate info logics Al Viro
2017-05-15 22:37 ` [PATCH 8/8] waitid(): switch copyout of siginfo to unsafe_put_user() Al Viro
2017-05-16 3:55 ` kbuild test robot
2017-05-16 4:17 ` kbuild test robot
2017-05-19 6:08 ` [lkp-robot] [waitid()] 75f64d68f9: Kernel_panic-not_syncing:Attempted_to_kill_init!exitcode= kernel test robot
2017-05-21 7:34 ` Al Viro
2017-05-21 19:04 ` Linus Torvalds
2017-05-21 19:35 ` Linus Torvalds
2017-05-21 21:14 ` Al Viro
2017-05-21 21:37 ` Linus Torvalds
2017-05-21 22:19 ` Linus Torvalds
2017-05-22 1:39 ` Linus Torvalds
2017-05-17 19:57 ` [RFC][PATCHSET] wait4()/waitid() cleanups Eric W. Biederman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170515223716.2085-3-viro@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=hch@lst.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox