[PATCH 2/3] core_pattern: allow passing of arguments to user mode helper when core_pattern is a pipe

From: Neil Horman
Date: Fri Jul 27 2007 - 16:09:55 EST


Hey
Patch 2/3 of my core_pattern enhancements. This patch is a rewrite of
my previous post for this enhancement. It uses jeremy's split_argv/free_argv
library functions to translate core_pattern into an argv array to be passed to
the user mode helper process. It also adds a translation to format_corename
such that the origional value of RLIMIT_CORE can be passed to userspace as an
argument.

Thanks & Regards
Neil

Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>


exec.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)


diff --git a/fs/exec.c b/fs/exec.c
index c0b5def..6855a52 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -51,6 +51,7 @@
#include <linux/cn_proc.h>
#include <linux/audit.h>
#include <linux/signalfd.h>
+#include <linux/string.h>

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -1543,6 +1544,14 @@ static int format_corename(char *corename, const char *pattern, long signr)
goto out;
out_ptr += rc;
break;
+ /* core limit size */
+ case 'c':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
default:
break;
}
@@ -1727,6 +1736,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
int flag = 0;
int ispipe = 0;
unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
+ char **helper_argv = NULL;
+ int helper_argc = 0;
+ char *delimit;

audit_core_dumps(signr);

@@ -1775,14 +1787,18 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
* at which point file size limits and permissions will be imposed
* as it does with any other process
*/
- if ((!ispipe) &&
- (core_limit < binfmt->min_coredump))
+ if ((!ispipe) && (core_limit < binfmt->min_coredump))
goto fail_unlock;

if (ispipe) {
core_limit = RLIM_INFINITY;
+ helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
+ /* Terminate the string before the first option */
+ delimit = strchr(corename, ' ');
+ if (delimit)
+ *delimit = '\0';
/* SIGPIPE can happen, but it's just never processed */
- if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) {
+ if(call_usermodehelper_pipe(corename+1, helper_argv, NULL, &file)) {
printk(KERN_INFO "Core dump to %s pipe failed\n",
corename);
goto fail_unlock;
@@ -1817,6 +1833,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
close_fail:
filp_close(file, NULL);
fail_unlock:
+ if (helper_argv)
+ argv_free(helper_argv);
+
current->fsuid = fsuid;
complete_all(&mm->core_done);
fail:
--
/***************************************************
*Neil Horman
*Software Engineer
*Red Hat, Inc.
*nhorman@xxxxxxxxxxxxx
*gpg keyid: 1024D / 0x92A74FA1
*http://pgp.mit.edu
***************************************************/
-
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