github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-29 18:51:21 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

coredump: massage do_coredump()

Browse Source 
We're going to extend the coredump code in follow-up patches.
Clean it up so we can do this more easily.

Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-2-664f3caf2516@kernel.org
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-05-16 13:25:29 +02:00
parent 727b55105a
commit d4fde206ab
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 65 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

122
fs/coredump.c
View File

@ -643,63 +643,8 @@ void do_coredump(const kernel_siginfo_t *siginfo)
goto fail_unlock;
}
if (cn.core_type == COREDUMP_PIPE) {
int argi;
int dump_count;
char **helper_argv;
struct subprocess_info *sub_info;
if (cprm.limit == 1) {
/* See umh_coredump_setup() which sets RLIMIT_CORE = 1.
*
* Normally core limits are irrelevant to pipes, since
* we're not writing to the file system, but we use
* cprm.limit of 1 here as a special value, this is a
* consistent way to catch recursive crashes.
* We can still crash if the core_pattern binary sets
* RLIM_CORE = !1, but it runs as root, and can do
* lots of stupid things.
*
* Note that we use task_tgid_vnr here to grab the pid
* of the process group leader. That way we get the
* right pid if a thread in a multi-threaded
* core_pattern process dies.
*/
coredump_report_failure("RLIMIT_CORE is set to 1, aborting core");
goto fail_unlock;
}
cprm.limit = RLIM_INFINITY;
dump_count = atomic_inc_return(&core_dump_count);
if (core_pipe_limit && (core_pipe_limit < dump_count)) {
coredump_report_failure("over core_pipe_limit, skipping core dump");
goto fail_dropcount;
}
helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv),
GFP_KERNEL);
if (!helper_argv) {
coredump_report_failure("%s failed to allocate memory", __func__);
goto fail_dropcount;
}
for (argi = 0; argi < argc; argi++)
helper_argv[argi] = cn.corename + argv[argi];
helper_argv[argi] = NULL;
retval = -ENOMEM;
sub_info = call_usermodehelper_setup(helper_argv[0],
helper_argv, NULL, GFP_KERNEL,
umh_coredump_setup, NULL, &cprm);
if (sub_info)
retval = call_usermodehelper_exec(sub_info,
UMH_WAIT_EXEC);
kfree(helper_argv);
if (retval) {
coredump_report_failure("|%s pipe failed", cn.corename);
goto close_fail;
}
} else if (cn.core_type == COREDUMP_FILE) {
switch (cn.core_type) {
case COREDUMP_FILE: {
struct mnt_idmap *idmap;
struct inode *inode;
int open_flags = O_CREAT | O_WRONLY | O_NOFOLLOW |
@ -793,6 +738,69 @@ void do_coredump(const kernel_siginfo_t *siginfo)
if (do_truncate(idmap, cprm.file->f_path.dentry,
0, 0, cprm.file))
goto close_fail;
break;
}
case COREDUMP_PIPE: {
int argi;
int dump_count;
char **helper_argv;
struct subprocess_info *sub_info;
if (cprm.limit == 1) {
/* See umh_coredump_setup() which sets RLIMIT_CORE = 1.
*
* Normally core limits are irrelevant to pipes, since
* we're not writing to the file system, but we use
* cprm.limit of 1 here as a special value, this is a
* consistent way to catch recursive crashes.
* We can still crash if the core_pattern binary sets
* RLIM_CORE = !1, but it runs as root, and can do
* lots of stupid things.
*
* Note that we use task_tgid_vnr here to grab the pid
* of the process group leader. That way we get the
* right pid if a thread in a multi-threaded
* core_pattern process dies.
*/
coredump_report_failure("RLIMIT_CORE is set to 1, aborting core");
goto fail_unlock;
}
cprm.limit = RLIM_INFINITY;
dump_count = atomic_inc_return(&core_dump_count);
if (core_pipe_limit && (core_pipe_limit < dump_count)) {
coredump_report_failure("over core_pipe_limit, skipping core dump");
goto fail_dropcount;
}
helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv),
GFP_KERNEL);
if (!helper_argv) {
coredump_report_failure("%s failed to allocate memory", __func__);
goto fail_dropcount;
}
for (argi = 0; argi < argc; argi++)
helper_argv[argi] = cn.corename + argv[argi];
helper_argv[argi] = NULL;
retval = -ENOMEM;
sub_info = call_usermodehelper_setup(helper_argv[0],
helper_argv, NULL, GFP_KERNEL,
umh_coredump_setup, NULL, &cprm);
if (sub_info)
retval = call_usermodehelper_exec(sub_info,
UMH_WAIT_EXEC);
kfree(helper_argv);
if (retval) {
coredump_report_failure("|%s pipe failed", cn.corename);
goto close_fail;
}
break;
}
default:
WARN_ON_ONCE(true);
goto close_fail;
}
/* get us an unshared descriptor table; almost always a no-op */