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authorLepton Wu <ytht.net@gmail.com>2020-08-11 18:36:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-12 10:58:01 -0700
commitf38c85f1ba6902e4e2e2bf1b84edf065a904cdeb (patch)
treeda822d6d9b11a6f56d2f28cb23509bcdb4918d7d
parent0776d1231bec0c7ab43baf440a3f5ef5f49dd795 (diff)
downloadmemblock-f38c85f1ba6902e4e2e2bf1b84edf065a904cdeb.tar.gz
coredump: add %f for executable filename
The document reads "%e" should be "executable filename" while actually it could be changed by things like pr_ctl PR_SET_NAME. People who uses "%e" in core_pattern get surprised when they find out they get thread name instead of executable filename. This is either a bug of document or a bug of code. Since the behavior of "%e" is there for long time, it could bring another surprise for users if we "fix" the code. So we just "fix" the document. And more, for users who really need the "executable filename" in core_pattern, we introduce a new "%f" for the real executable filename. We already have "%E" for executable path in kernel, so just reuse most of its code for the new added "%f" format. Signed-off-by: Lepton Wu <ytht.net@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200701031432.2978761-1-ytht.net@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/admin-guide/sysctl/kernel.rst3
-rw-r--r--fs/coredump.c17
2 files changed, 15 insertions, 5 deletions
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 2ae9669eb22c82..d4b32cc32bb790 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -164,7 +164,8 @@ core_pattern
%s signal number
%t UNIX time of dump
%h hostname
- %e executable filename (may be shortened)
+ %e executable filename (may be shortened, could be changed by prctl etc)
+ %f executable filename
%E executable path
%c maximum size of core file by resource limit RLIMIT_CORE
%<OTHER> both are dropped
diff --git a/fs/coredump.c b/fs/coredump.c
index 7237f07ff6bed2..76e7c10edfc030 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -153,10 +153,10 @@ int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
return ret;
}
-static int cn_print_exe_file(struct core_name *cn)
+static int cn_print_exe_file(struct core_name *cn, bool name_only)
{
struct file *exe_file;
- char *pathbuf, *path;
+ char *pathbuf, *path, *ptr;
int ret;
exe_file = get_mm_exe_file(current->mm);
@@ -175,6 +175,11 @@ static int cn_print_exe_file(struct core_name *cn)
goto free_buf;
}
+ if (name_only) {
+ ptr = strrchr(path, '/');
+ if (ptr)
+ path = ptr + 1;
+ }
ret = cn_esc_printf(cn, "%s", path);
free_buf:
@@ -301,12 +306,16 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm,
utsname()->nodename);
up_read(&uts_sem);
break;
- /* executable */
+ /* executable, could be changed by prctl PR_SET_NAME etc */
case 'e':
err = cn_esc_printf(cn, "%s", current->comm);
break;
+ /* file name of executable */
+ case 'f':
+ err = cn_print_exe_file(cn, true);
+ break;
case 'E':
- err = cn_print_exe_file(cn);
+ err = cn_print_exe_file(cn, false);
break;
/* core limit size */
case 'c':