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authorZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2014-06-23 20:18:16 -0400
committerZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2014-06-23 23:14:54 -0400
commit1eef15b181507f95dc41ec00a0eef5c0a7499351 (patch)
tree8c5cf7120ade86658a8db4e2b1f20052d1d8658c
parent75a59316ea0d4bb9d04cce138817d9fa8a75479f (diff)
coredump: retrieve comm information from /proc
Kernel mangles comm information in an irreversible way when comm constains repeated spaces. Retrieve comm information from /proc, and only fallback to the information provided on the commandline when retrieving information from /proc fails. Add exe information to the list of saved xattr. https://bugs.freedesktop.org/show_bug.cgi?id=62043
-rw-r--r--src/journal/coredump.c133
1 files changed, 83 insertions, 50 deletions
diff --git a/src/journal/coredump.c b/src/journal/coredump.c
index 1b35eb1698..4d9ef1c7ee 100644
--- a/src/journal/coredump.c
+++ b/src/journal/coredump.c
@@ -31,6 +31,7 @@
#include "log.h"
#include "util.h"
+#include "strv.h"
#include "macro.h"
#include "mkdir.h"
#include "special.h"
@@ -62,13 +63,14 @@
assert_cc(JOURNAL_SIZE_MAX <= ENTRY_SIZE_MAX);
enum {
- ARG_PID = 1,
- ARG_UID,
- ARG_GID,
- ARG_SIGNAL,
- ARG_TIMESTAMP,
- ARG_COMM,
- _ARG_MAX
+ INFO_PID,
+ INFO_UID,
+ INFO_GID,
+ INFO_SIGNAL,
+ INFO_TIMESTAMP,
+ INFO_COMM,
+ INFO_EXE,
+ _INFO_LEN
};
typedef enum CoredumpStorage {
@@ -159,28 +161,32 @@ static int fix_acl(int fd, uid_t uid) {
return 0;
}
-static int fix_xattr(int fd, char *argv[]) {
+static int fix_xattr(int fd, const char *info[_INFO_LEN]) {
- static const char * const xattrs[_ARG_MAX] = {
- [ARG_PID] = "user.coredump.pid",
- [ARG_UID] = "user.coredump.uid",
- [ARG_GID] = "user.coredump.gid",
- [ARG_SIGNAL] = "user.coredump.signal",
- [ARG_TIMESTAMP] = "user.coredump.timestamp",
- [ARG_COMM] = "user.coredump.comm",
+ static const char * const xattrs[_INFO_LEN] = {
+ [INFO_PID] = "user.coredump.pid",
+ [INFO_UID] = "user.coredump.uid",
+ [INFO_GID] = "user.coredump.gid",
+ [INFO_SIGNAL] = "user.coredump.signal",
+ [INFO_TIMESTAMP] = "user.coredump.timestamp",
+ [INFO_COMM] = "user.coredump.comm",
+ [INFO_EXE] = "user.coredump.exe",
};
int r = 0;
unsigned i;
- /* Attach some metadate to coredumps via extended
+ /* Attach some metadata to coredumps via extended
* attributes. Just because we can. */
- for (i = 0; i < _ARG_MAX; i++) {
- if (isempty(argv[i]))
+ for (i = 0; i < _INFO_LEN; i++) {
+ int k;
+
+ if (isempty(info[i]) || !xattrs[i])
continue;
- if (fsetxattr(fd, xattrs[i], argv[i], strlen(argv[i]), XATTR_CREATE) < 0)
+ k = fsetxattr(fd, xattrs[i], info[i], strlen(info[i]), XATTR_CREATE);
+ if (k < 0 && r == 0)
r = -errno;
}
@@ -189,27 +195,32 @@ static int fix_xattr(int fd, char *argv[]) {
#define filename_escape(s) xescape((s), "./ ")
-static int save_external_coredump(char **argv, uid_t uid, char **ret_filename, int *ret_fd, off_t *ret_size) {
+static int save_external_coredump(const char *info[_INFO_LEN],
+ uid_t uid,
+ char **ret_filename,
+ int *ret_fd,
+ off_t *ret_size) {
+
_cleanup_free_ char *p = NULL, *t = NULL, *c = NULL, *fn = NULL, *tmp = NULL;
_cleanup_close_ int fd = -1;
sd_id128_t boot;
struct stat st;
int r;
- assert(argv);
+ assert(info);
assert(ret_filename);
assert(ret_fd);
assert(ret_size);
- c = filename_escape(argv[ARG_COMM]);
+ c = filename_escape(info[INFO_COMM]);
if (!c)
return log_oom();
- p = filename_escape(argv[ARG_PID]);
+ p = filename_escape(info[INFO_PID]);
if (!p)
return log_oom();
- t = filename_escape(argv[ARG_TIMESTAMP]);
+ t = filename_escape(info[INFO_TIMESTAMP]);
if (!t)
return log_oom();
@@ -242,10 +253,12 @@ static int save_external_coredump(char **argv, uid_t uid, char **ret_filename, i
r = copy_bytes(STDIN_FILENO, fd, arg_process_size_max);
if (r == -E2BIG) {
- log_error("Coredump of %s (%s) is larger than configured processing limit, refusing.", argv[ARG_PID], argv[ARG_COMM]);
+ log_error("Coredump of %s (%s) is larger than configured processing limit, refusing.",
+ info[INFO_PID], info[INFO_COMM]);
goto fail;
} else if (IN_SET(r, -EDQUOT, -ENOSPC)) {
- log_error("Not enough disk space for coredump of %s (%s), refusing.", argv[ARG_PID], argv[ARG_COMM]);
+ log_error("Not enough disk space for coredump of %s (%s), refusing.",
+ info[INFO_PID], info[INFO_COMM]);
goto fail;
} else if (r < 0) {
log_error("Failed to dump coredump to file: %s", strerror(-r));
@@ -255,22 +268,22 @@ static int save_external_coredump(char **argv, uid_t uid, char **ret_filename, i
/* Ignore errors on these */
fchmod(fd, 0640);
fix_acl(fd, uid);
- fix_xattr(fd, argv);
+ fix_xattr(fd, info);
if (fsync(fd) < 0) {
- log_error("Failed to sync coredump: %m");
+ log_error("Failed to sync coredump %s: %m", tmp);
r = -errno;
goto fail;
}
if (fstat(fd, &st) < 0) {
- log_error("Failed to fstat coredump: %m");
+ log_error("Failed to fstat coredump %s: %m", tmp);
r = -errno;
goto fail;
}
if (rename(tmp, fn) < 0) {
- log_error("Failed to rename coredump: %m");
+ log_error("Failed to rename coredump %s -> %s: %m", tmp, fn);
r = -errno;
goto fail;
}
@@ -351,7 +364,8 @@ int main(int argc, char* argv[]) {
*core_timestamp = NULL, *core_comm = NULL, *core_exe = NULL, *core_unit = NULL,
*core_session = NULL, *core_message = NULL, *core_cmdline = NULL, *coredump_data = NULL,
*coredump_filename = NULL, *core_slice = NULL, *core_cgroup = NULL, *core_owner_uid = NULL,
- *exe = NULL;
+ *exe = NULL, *comm = NULL;
+ const char *info[_INFO_LEN];
_cleanup_close_ int coredump_fd = -1;
@@ -372,8 +386,9 @@ int main(int argc, char* argv[]) {
log_set_target(LOG_TARGET_KMSG);
log_open();
- if (argc != _ARG_MAX) {
- log_error("Invalid number of arguments passed from kernel.");
+ if (argc < INFO_COMM + 1) {
+ log_error("Not enough arguments passed from kernel (%d, expected %d).",
+ argc - 1, INFO_COMM + 1 - 1);
r = -EINVAL;
goto finish;
}
@@ -389,24 +404,40 @@ int main(int argc, char* argv[]) {
goto finish;
}
- r = parse_uid(argv[ARG_UID], &uid);
+ r = parse_uid(argv[INFO_UID + 1], &uid);
if (r < 0) {
log_error("Failed to parse UID.");
goto finish;
}
- r = parse_pid(argv[ARG_PID], &pid);
+ r = parse_pid(argv[INFO_PID + 1], &pid);
if (r < 0) {
log_error("Failed to parse PID.");
goto finish;
}
- r = parse_gid(argv[ARG_GID], &gid);
+ r = parse_gid(argv[INFO_GID + 1], &gid);
if (r < 0) {
log_error("Failed to parse GID.");
goto finish;
}
+ if (get_process_comm(pid, &comm) < 0) {
+ log_warning("Failed to get COMM, falling back to the commandline.");
+ comm = strv_join(argv + INFO_COMM + 1, " ");
+ }
+
+ if (get_process_exe(pid, &exe) < 0)
+ log_warning("Failed to get EXE.");
+
+ info[INFO_PID] = argv[INFO_PID + 1];
+ info[INFO_UID] = argv[INFO_UID + 1];
+ info[INFO_GID] = argv[INFO_GID + 1];
+ info[INFO_SIGNAL] = argv[INFO_SIGNAL + 1];
+ info[INFO_TIMESTAMP] = argv[INFO_TIMESTAMP + 1];
+ info[INFO_COMM] = comm;
+ info[INFO_EXE] = exe;
+
if (cg_pid_get_unit(pid, &t) >= 0) {
if (streq(t, SPECIAL_JOURNALD_SERVICE)) {
@@ -418,7 +449,7 @@ int main(int argc, char* argv[]) {
if (arg_storage != COREDUMP_STORAGE_NONE)
arg_storage = COREDUMP_STORAGE_EXTERNAL;
- r = save_external_coredump(argv, uid, &coredump_filename, &coredump_fd, &coredump_size);
+ r = save_external_coredump(info, uid, &coredump_filename, &coredump_fd, &coredump_size);
if (r < 0)
goto finish;
@@ -442,26 +473,22 @@ int main(int argc, char* argv[]) {
log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
log_open();
- core_pid = strappend("COREDUMP_PID=", argv[ARG_PID]);
+ core_pid = strappend("COREDUMP_PID=", info[INFO_PID]);
if (core_pid)
IOVEC_SET_STRING(iovec[j++], core_pid);
- core_uid = strappend("COREDUMP_UID=", argv[ARG_UID]);
+ core_uid = strappend("COREDUMP_UID=", info[INFO_UID]);
if (core_uid)
IOVEC_SET_STRING(iovec[j++], core_uid);
- core_gid = strappend("COREDUMP_GID=", argv[ARG_GID]);
+ core_gid = strappend("COREDUMP_GID=", info[INFO_GID]);
if (core_gid)
IOVEC_SET_STRING(iovec[j++], core_gid);
- core_signal = strappend("COREDUMP_SIGNAL=", argv[ARG_SIGNAL]);
+ core_signal = strappend("COREDUMP_SIGNAL=", info[INFO_SIGNAL]);
if (core_signal)
IOVEC_SET_STRING(iovec[j++], core_signal);
- core_comm = strappend("COREDUMP_COMM=", argv[ARG_COMM]);
- if (core_comm)
- IOVEC_SET_STRING(iovec[j++], core_comm);
-
if (sd_pid_get_session(pid, &t) >= 0) {
core_session = strappend("COREDUMP_SESSION=", t);
free(t);
@@ -485,7 +512,13 @@ int main(int argc, char* argv[]) {
IOVEC_SET_STRING(iovec[j++], core_slice);
}
- if (get_process_exe(pid, &exe) >= 0) {
+ if (comm) {
+ core_comm = strappend("COREDUMP_COMM=", comm);
+ if (core_comm)
+ IOVEC_SET_STRING(iovec[j++], core_comm);
+ }
+
+ if (exe) {
core_exe = strappend("COREDUMP_EXE=", exe);
if (core_exe)
IOVEC_SET_STRING(iovec[j++], core_exe);
@@ -507,7 +540,7 @@ int main(int argc, char* argv[]) {
IOVEC_SET_STRING(iovec[j++], core_cgroup);
}
- core_timestamp = strjoin("COREDUMP_TIMESTAMP=", argv[ARG_TIMESTAMP], "000000", NULL);
+ core_timestamp = strjoin("COREDUMP_TIMESTAMP=", info[INFO_TIMESTAMP], "000000", NULL);
if (core_timestamp)
IOVEC_SET_STRING(iovec[j++], core_timestamp);
@@ -515,7 +548,7 @@ int main(int argc, char* argv[]) {
IOVEC_SET_STRING(iovec[j++], "PRIORITY=2");
/* Always stream the coredump to disk, if that's possible */
- r = save_external_coredump(argv, uid, &coredump_filename, &coredump_fd, &coredump_size);
+ r = save_external_coredump(info, uid, &coredump_filename, &coredump_fd, &coredump_size);
if (r < 0)
goto finish;
@@ -546,14 +579,14 @@ int main(int argc, char* argv[]) {
r = coredump_make_stack_trace(coredump_fd, exe, &stacktrace);
if (r >= 0)
- core_message = strjoin("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") of user ", argv[ARG_UID], " dumped core.\n\n", stacktrace, NULL);
+ core_message = strjoin("MESSAGE=Process ", info[INFO_PID], " (", comm, ") of user ", info[INFO_UID], " dumped core.\n\n", stacktrace, NULL);
else
log_warning("Failed to generate stack trace: %s", strerror(-r));
}
if (!core_message)
#endif
- core_message = strjoin("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") of user ", argv[ARG_UID], " dumped core.", NULL);
+ core_message = strjoin("MESSAGE=Process ", info[INFO_PID], " (", comm, ") of user ", info[INFO_UID], " dumped core.", NULL);
if (core_message)
IOVEC_SET_STRING(iovec[j++], core_message);