Re: [PATCH] [RFC] coredump: Ensure that the coredump helper has stdoutand stderr

From: Richard Weinberger
Date: Thu Oct 04 2012 - 07:07:10 EST


On 28.09.2012 18:32, Richard Weinberger wrote:
Currently only stdin is available in the coredump helper process.
If the process opens a file and then issues a printf(),
printf() will write to that opened file instead to a console.

Therefore open /dev/console and create fd 1 and 0 as init/main.c does.
sys_close(0) is only needed if sys_open() succeeds.
Before this patch it was in vain and returned always -EBADF because nobody
opened fd 0.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
fs/exec.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/exec.c b/fs/exec.c
index 574cf4d..2912fec 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -2079,7 +2079,13 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)

cp->file = files[1];

- sys_close(0);
+ /* Ensure that the process has stdout and stderr */
+ if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) == 0) {
+ sys_dup(0);
+ sys_dup(0);
+ sys_close(0);
+ }
+
fd_install(0, files[0]);
spin_lock(&cf->file_lock);
fdt = files_fdtable(cf);


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