From: Eric Wong <e@80x24.org>
To: mwrap-perl@80x24.org
Subject: [PATCH 3/4] %p => PID expansion for dump_path + dump_csv
Date: Wed, 11 Jan 2023 01:12:48 +0000 [thread overview]
Message-ID: <20230111011249.2713039-4-e@80x24.org> (raw)
In-Reply-To: <20230111011249.2713039-1-e@80x24.org>
This makes it possible to dump per-PID files for processes which
fork. `%p' matches what the Linux sys.kernel.core_pattern
sysctl understands.
---
mwrap_core.h | 15 +++++++++++++++
script/mwrap-perl | 6 ++++++
t/mwrap.t | 15 +++++++++++++++
3 files changed, 36 insertions(+)
diff --git a/mwrap_core.h b/mwrap_core.h
index fff0538..86e4498 100644
--- a/mwrap_core.h
+++ b/mwrap_core.h
@@ -895,12 +895,27 @@ __attribute__ ((destructor)) static void mwrap_dtor(void)
if (dump_path) {
char *end = strchr(dump_path, ',');
char buf[PATH_MAX];
+ AUTO_FREE char *pid_path = NULL;
if (end) {
mwrap_assert((end - dump_path) < (intptr_t)sizeof(buf));
end = mempcpy(buf, dump_path, end - dump_path);
*end = 0;
dump_path = buf;
}
+
+ /* %p => PID expansion (Linux core_pattern uses %p, too) */
+ if ((s = strchr(dump_path, '%')) && s[1] == 'p' &&
+ /* don't allow injecting extra formats: */
+ !strchr(s + 2, '%')) {
+ s[1] = 'd'; /* s/%p/%d/ to make asprintf happy */
+ int n = asprintf(&pid_path, dump_path, (int)getpid());
+ if (n < 0)
+ fprintf(stderr,
+ "asprintf failed: %m, dumping to %s\n",
+ dump_path);
+ else
+ dump_path = pid_path;
+ }
dump_fd = open(dump_path, O_CLOEXEC|O_WRONLY|O_APPEND|O_CREAT,
0666);
if (dump_fd < 0) {
diff --git a/script/mwrap-perl b/script/mwrap-perl
index eb29176..371aee6 100644
--- a/script/mwrap-perl
+++ b/script/mwrap-perl
@@ -76,6 +76,10 @@ Dumps the output at exit to a given filename:
total_bytes call_count location
+C<$FILENAME> may contain C<%p> where C<%p> is a placeholder for
+the PID being dumped. No other use of C<%> is accepted, and
+multiple C<%> means all C<%> (including C<%p>) are handled as-is.
+
=item dump_fd:$DESCRIPTOR
As with dump_path, but dumps the output to a given file descriptor.
@@ -90,6 +94,8 @@ but is subject to change in future releases.
C<dump_csv> without the C<:> may also be used in conjunction with
C<dump_fd>, such as C<MWRAP=dump_fd:2,dump_csv>.
+Expands C<%p> to the PID in C<$FILENAME> as described for C<dump_path:>
+
=back
=head1 HTTP POST API
diff --git a/t/mwrap.t b/t/mwrap.t
index ccd739b..783f6e7 100644
--- a/t/mwrap.t
+++ b/t/mwrap.t
@@ -42,6 +42,21 @@ my $dump = "$mwrap_tmp/dump";
$nr_comma = ($s =~ tr/,/,/);
$nr_cr = ($s =~ tr/\n/\n/);
ok($nr_comma > ($nr_cr * 4), 'CSV has more commas than CR');
+
+ $env->{MWRAP} = "dump_path:$dump.%p";
+ mwrap_run('dump_path PID expansion', $env, '-e', $script);
+ my @d = grep(/\.\d+\z/, glob("$dump.*"));
+ is(scalar(@d), 1, 'got PID file') or diag explain([glob("$dump*")]);
+ unlink(@d) or BAIL_OUT "unlink: $!";
+
+ # don't allow injecting random formats
+ for my $fmt ('%p.%m', '%m.%p') {
+ my $fn = $dump.$fmt;
+ $env->{MWRAP} = "dump_path:$fn";
+ mwrap_run("PID expansion fails on $fmt", $env, '-e', $script);
+ ok($fn, "$fmt used as-is");
+ unlink($fn) or BAIL_OUT "unlink: $!";
+ }
}
SKIP: { # C++ program which uses malloc via "new"
next prev parent reply other threads:[~2023-01-11 1:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 1:12 [PATCH 0/4] CSV-related improvements Eric Wong
2023-01-11 1:12 ` [PATCH 1/4] support MWRAP=dump_csv:$FILENAME parameter Eric Wong
2023-01-11 1:12 ` [PATCH 2/4] add mwrap-decode-csv tool Eric Wong
2023-01-11 1:12 ` Eric Wong [this message]
2023-01-11 1:12 ` [PATCH 4/4] rewrite README and update manpage to favor CSV Eric Wong
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