Commit 910003d0 authored by Colin Walters's avatar Colin Walters Committed by Zbigniew Jędrzejewski-Szmek

coredump: use realloc() loop instead of malloc(768M)

I typically run VMs with 1024MiB allocated; systemd is unable to write
coredumps in this scenario at all because the default kernel
configuration will only overcommit 50% of available RAM.

Avoid this failure by using a realloc() loop.

See: http://lists.freedesktop.org/archives/systemd-devel/2013-April/010709.html
parent 45df1f2c
......@@ -37,6 +37,8 @@
#include "special.h"
#include "cgroup-util.h"
/* Few programs have less than 3MiB resident */
#define COREDUMP_MIN_START (3*1024*1024)
/* Make sure to not make this larger than the maximum journal entry
* size. See ENTRY_SIZE_MAX in journald-native.c. */
#define COREDUMP_MAX (768*1024*1024)
......@@ -103,9 +105,10 @@ int main(int argc, char* argv[]) {
uid_t uid;
gid_t gid;
struct iovec iovec[14];
size_t coredump_bufsize, coredump_size;
_cleanup_free_ char *core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL,
*core_timestamp = NULL, *core_comm = NULL, *core_exe = NULL, *core_unit = NULL,
*core_session = NULL, *core_message = NULL, *core_cmdline = NULL, *p = NULL;
*core_session = NULL, *core_message = NULL, *core_cmdline = NULL, *coredump_data = NULL;
prctl(PR_SET_DUMPABLE, 0);
......@@ -234,23 +237,35 @@ int main(int argc, char* argv[]) {
goto finish;
}
p = malloc(9 + COREDUMP_MAX);
if (!p) {
coredump_bufsize = COREDUMP_MIN_START;
coredump_data = malloc(coredump_bufsize);
if (!coredump_data) {
r = log_oom();
goto finish;
}
memcpy(p, "COREDUMP=", 9);
memcpy(coredump_data, "COREDUMP=", 9);
coredump_size = 9;
n = loop_read(STDIN_FILENO, p + 9, COREDUMP_MAX, false);
if (n < 0) {
log_error("Failed to read core dump data: %s", strerror(-n));
r = (int) n;
goto finish;
for (;;) {
n = loop_read(STDIN_FILENO, coredump_data + coredump_size,
coredump_bufsize - coredump_size, false);
if (n < 0) {
log_error("Failed to read core dump data: %s", strerror(-n));
r = (int) n;
goto finish;
} else if (n == 0)
break;
coredump_size += n;
if (!GREEDY_REALLOC(coredump_data, coredump_bufsize, coredump_size + 1)) {
r = log_oom();
goto finish;
}
}
iovec[j].iov_base = p;
iovec[j].iov_len = 9 + n;
iovec[j].iov_base = coredump_data;
iovec[j].iov_len = coredump_size;
j++;
r = sd_journal_sendv(iovec, j);
......
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