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author | Eric Wong <e@80x24.org> | 2023-01-11 01:12:48 +0000 |
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committer | Eric Wong <mwrap-perl@80x24.org> | 2023-01-11 04:23:31 +0000 |
commit | 64a55ae0ba1d09ccda458eb895d849e7d38cab81 (patch) | |
tree | 10f5f5d99c49de5ba17277540a786a477f9e9c5c | |
parent | 86d350a3854af1a5a292972d4f70154e61ce5e80 (diff) | |
download | mwrap-64a55ae0ba1d09ccda458eb895d849e7d38cab81.tar.gz |
%p => PID expansion for dump_path + dump_csv
This makes it possible to dump per-PID files for processes which fork. `%p' matches what the Linux sys.kernel.core_pattern sysctl understands.
-rw-r--r-- | mwrap_core.h | 15 | ||||
-rw-r--r-- | script/mwrap-perl | 6 | ||||
-rw-r--r-- | t/mwrap.t | 15 |
3 files changed, 36 insertions, 0 deletions
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 @@ -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" |