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coredumpctl: delay the "on tty" refusal until as late as possible

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For the user, if the core file is missing or inaccessible, it is
more interesting that the fact that they forgot to pipe to a file.
So delay the failure from the check until after we have verified
that the file or the COREDUMP field are present.

Partially fixes #4161.

Also, error reporting on failure was duplicated. save_core() now
always prints an error message (because it knows the paths involved,
so can the most useful message), and the callers don't have to.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2016-09-27 00:32:42 +02:00
parent 062b99e8be
commit bb7c5bad4a
1 changed files with 43 additions and 23 deletions
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66
src/coredump/coredumpctl.c
View file

@ -617,26 +617,34 @@ static int dump_list(sd_journal *j) {
return 0;
}
static int save_core(sd_journal *j, int fd, char **path, bool *unlink_temp) {
static int save_core(sd_journal *j, FILE *file, char **path, bool *unlink_temp) {
const char *data;
_cleanup_free_ char *filename = NULL;
size_t len;
int r;
int r, fd;
_cleanup_close_ int fdt = -1;
char *temp = NULL;
assert((fd >= 0) != !!path);
assert(!!path == !!unlink_temp);
/* We want full data, nothing truncated. */
sd_journal_set_data_threshold(j, 0);
assert(!(file && path)); /* At most one can be specified */
assert(!!path == !!unlink_temp); /* Those must be specified together */
/* Look for a coredump on disk first. */
r = sd_journal_get_data(j, "COREDUMP_FILENAME", (const void**) &data, &len);
if (r < 0 && r != -ENOENT)
return log_error_errno(r, "Failed to retrieve COREDUMP_FILENAME: %m");
else if (r == 0)
if (r == 0)
retrieve(data, len, "COREDUMP_FILENAME", &filename);
else {
if (r != -ENOENT)
return log_error_errno(r, "Failed to retrieve COREDUMP_FILENAME field: %m");
/* Check that we can have a COREDUMP field. We still haven't set a high
* data threshold, so we'll get a few kilobytes at most.
*/
r = sd_journal_get_data(j, "COREDUMP", (const void**) &data, &len);
if (r == -ENOENT)
return log_error_errno(r, "Coredump entry has no core attached (neither internally in the journal nor externally on disk).");
if (r < 0)
return log_error_errno(r, "Failed to retrieve COREDUMP field: %m");
}
if (filename) {
if (access(filename, R_OK) < 0)
@ -650,7 +658,7 @@ static int save_core(sd_journal *j, int fd, char **path, bool *unlink_temp) {
}
}
if (fd < 0) {
if (path) {
const char *vt;
/* Create a temporary file to write the uncompressed core to. */
@ -669,6 +677,22 @@ static int save_core(sd_journal *j, int fd, char **path, bool *unlink_temp) {
log_debug("Created temporary file %s", temp);
fd = fdt;
} else {
/* If neither path or file are specified, we will write to stdout. Let's now check
* if stdout is connected to a tty. We checked that the file exists, or that the
* core might be stored in the journal. In this second case, if we found the entry,
* in all likelyhood we will be able to access the COREDUMP= field. In either case,
* we stop before doing any "real" work, i.e. before starting decompression or
* reading from the file or creating temporary files.
*/
if (!file) {
if (on_tty())
return log_error_errno(ENOTTY, "Refusing to dump core to tty"
" (use shell redirection or specify --output).");
file = stdout;
}
fd = fileno(file);
}
if (filename) {
@ -694,11 +718,12 @@ static int save_core(sd_journal *j, int fd, char **path, bool *unlink_temp) {
} else {
ssize_t sz;
/* We want full data, nothing truncated. */
sd_journal_set_data_threshold(j, 0);
r = sd_journal_get_data(j, "COREDUMP", (const void**) &data, &len);
if (r < 0)
return log_error_errno(r,
r == -ENOENT ? "Core file was not saved for this entry." :
"Failed to retrieve COREDUMP field: %m");
return log_error_errno(r, "Failed to retrieve COREDUMP field: %m");
assert(len >= 9);
data += 9;
@ -741,14 +766,9 @@ static int dump_core(sd_journal* j) {
print_info(arg_output ? stdout : stderr, j, false);
if (on_tty() && !arg_output) {
log_error("Refusing to dump core to tty.");
return -ENOTTY;
}
r = save_core(j, arg_output ? fileno(arg_output) : STDOUT_FILENO, NULL, NULL);
r = save_core(j, arg_output, NULL, NULL);
if (r < 0)
return log_error_errno(r, "Coredump retrieval failed: %m");
return r;
r = sd_journal_previous(j);
if (r > 0)
@ -797,9 +817,9 @@ static int run_gdb(sd_journal *j) {
return -ENOENT;
}
r = save_core(j, -1, &path, &unlink_path);
r = save_core(j, NULL, &path, &unlink_path);
if (r < 0)
return log_error_errno(r, "Failed to retrieve core: %m");
return r;
pid = fork();
if (pid < 0) {