From a276ae74299fbdcf3321740c74fbf97501c63aad Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 18 Jun 2014 23:05:15 +0200 Subject: [PATCH 1/1] coredump: make sure coredumpctl can handle externally stored coredumps --- src/journal/coredumpctl.c | 255 +++++++++++++++++++++++++++----------- 1 file changed, 182 insertions(+), 73 deletions(-) diff --git a/src/journal/coredumpctl.c b/src/journal/coredumpctl.c index bf943bc03..db0f3d67c 100644 --- a/src/journal/coredumpctl.c +++ b/src/journal/coredumpctl.c @@ -36,6 +36,7 @@ #include "pager.h" #include "macro.h" #include "journal-internal.h" +#include "copy.h" static enum { ACTION_NONE, @@ -45,7 +46,7 @@ static enum { } arg_action = ACTION_LIST; static FILE* output = NULL; -static char* field = NULL; +static char* arg_field = NULL; static int arg_no_pager = false; static int arg_no_legend = false; @@ -79,21 +80,21 @@ static Set *new_matches(void) { } static int help(void) { - printf("%s [OPTIONS...] [MATCHES...]\n\n" + + printf("%s [OPTIONS...]\n\n" "List or retrieve coredumps from the journal.\n\n" "Flags:\n" - " -o --output=FILE Write output to FILE\n" - " --no-pager Do not pipe output into a pager\n" - " --no-legend Do not print the column headers.\n\n" + " -o --output=FILE Write output to FILE\n" + " --no-pager Do not pipe output into a pager\n" + " --no-legend Do not print the column headers.\n\n" "Commands:\n" - " -h --help Show this help\n" - " --version Print version string\n" - " -F --field=FIELD List all values a certain field takes\n" - " gdb Start gdb for the first matching coredump\n" - " list List available coredumps\n" - " dump PID Print coredump to stdout\n" - " dump PATH Print coredump to stdout\n" + " -h --help Show this help\n" + " --version Print version string\n" + " -F --field=FIELD List all values a certain field takes\n" + " list [MATCHES...] List available coredumps\n" + " dump [MATCHES...] Print first matching coredump to stdout\n" + " gdb [MATCHES...] Start gdb for the first matching coredump\n" , program_invocation_short_name); return 0; @@ -198,12 +199,12 @@ static int parse_argv(int argc, char *argv[], Set *matches) { break; case 'F': - if (field) { + if (arg_field) { log_error("cannot use --field/-F more than once"); return -EINVAL; } - field = optarg; + arg_field = optarg; break; case '?': @@ -227,7 +228,7 @@ static int parse_argv(int argc, char *argv[], Set *matches) { } } - if (field && arg_action != ACTION_LIST) { + if (arg_field && arg_action != ACTION_LIST) { log_error("Option --field/-F only makes sense with list"); return -EINVAL; } @@ -245,9 +246,10 @@ static int parse_argv(int argc, char *argv[], Set *matches) { static int retrieve(const void *data, size_t len, const char *name, - const char **var) { + char **var) { size_t ident; + char *v; ident = strlen(name) + 1; /* name + "=" */ @@ -260,30 +262,34 @@ static int retrieve(const void *data, if (((const char*) data)[ident - 1] != '=') return 0; - *var = strndup((const char*)data + ident, len - ident); - if (!*var) + v = strndup((const char*)data + ident, len - ident); + if (!v) return log_oom(); + free(*var); + *var = v; + return 0; } static void print_field(FILE* file, sd_journal *j) { - _cleanup_free_ const char *value = NULL; + _cleanup_free_ char *value = NULL; const void *d; size_t l; - assert(field); + assert(arg_field); SD_JOURNAL_FOREACH_DATA(j, d, l) - retrieve(d, l, field, &value); + retrieve(d, l, arg_field, &value); + if (value) fprintf(file, "%s\n", value); } static int print_entry(FILE* file, sd_journal *j, int had_legend) { - _cleanup_free_ const char + _cleanup_free_ char *pid = NULL, *uid = NULL, *gid = NULL, - *sgnl = NULL, *exe = NULL; + *sgnl = NULL, *exe = NULL, *comm = NULL, *cmdline = NULL; const void *d; size_t l; usec_t t; @@ -291,19 +297,16 @@ static int print_entry(FILE* file, sd_journal *j, int had_legend) { int r; SD_JOURNAL_FOREACH_DATA(j, d, l) { - retrieve(d, l, "COREDUMP_PID", &pid); retrieve(d, l, "COREDUMP_PID", &pid); retrieve(d, l, "COREDUMP_UID", &uid); retrieve(d, l, "COREDUMP_GID", &gid); retrieve(d, l, "COREDUMP_SIGNAL", &sgnl); retrieve(d, l, "COREDUMP_EXE", &exe); - if (!exe) - retrieve(d, l, "COREDUMP_COMM", &exe); - if (!exe) - retrieve(d, l, "COREDUMP_CMDLINE", &exe); + retrieve(d, l, "COREDUMP_COMM", &comm); + retrieve(d, l, "COREDUMP_CMDLINE", &cmdline); } - if (!pid && !uid && !gid && !sgnl && !exe) { + if (!pid && !uid && !gid && !sgnl && !exe && !comm && !cmdline) { log_warning("Empty coredump log entry"); return -EINVAL; } @@ -327,11 +330,11 @@ static int print_entry(FILE* file, sd_journal *j, int had_legend) { fprintf(file, "%*s %*s %*s %*s %*s %s\n", FORMAT_TIMESTAMP_MAX-1, buf, - 6, pid, - 5, uid, - 5, gid, - 3, sgnl, - exe); + 6, strna(pid), + 5, strna(uid), + 5, strna(gid), + 3, strna(sgnl), + strna(exe ?: (comm ?: cmdline))); return 0; } @@ -347,13 +350,13 @@ static int dump_list(sd_journal *j) { sd_journal_set_data_threshold(j, 4096); SD_JOURNAL_FOREACH(j) { - if (field) + if (arg_field) print_field(stdout, j); else print_entry(stdout, j, found++); } - if (!field && !found) { + if (!arg_field && !found) { log_notice("No coredumps found"); return -ESRCH; } @@ -378,6 +381,55 @@ static int focus(sd_journal *j) { return r; } +#define filename_escape(s) xescape((s), "./") + +static int make_coredump_path(sd_journal *j, char **ret) { + _cleanup_free_ char + *pid = NULL, *boot_id = NULL, *tstamp = NULL, *comm = NULL, + *p = NULL, *b = NULL, *t = NULL, *c = NULL; + const void *d; + size_t l; + char *fn; + + assert(j); + assert(ret); + + SD_JOURNAL_FOREACH_DATA(j, d, l) { + retrieve(d, l, "COREDUMP_COMM", &comm); + retrieve(d, l, "COREDUMP_PID", &pid); + retrieve(d, l, "COREDUMP_TIMESTAMP", &tstamp); + retrieve(d, l, "_BOOT_ID", &boot_id); + } + + if (!pid || !comm || !tstamp || !boot_id) { + log_error("Failed to retrieve necessary fields to find coredump on disk."); + return -ENOENT; + } + + p = filename_escape(pid); + if (!p) + return log_oom(); + + t = filename_escape(tstamp); + if (!t) + return log_oom(); + + c = filename_escape(comm); + if (!t) + return log_oom(); + + b = filename_escape(boot_id); + if (!b) + return log_oom(); + + fn = strjoin("/var/lib/systemd/coredump/core.", c, ".", b, ".", p, ".", t, NULL); + if (!fn) + return log_oom(); + + *ret = fn; + return 0; +} + static int dump_core(sd_journal* j) { const void *data; size_t len, ret; @@ -400,19 +452,44 @@ static int dump_core(sd_journal* j) { } r = sd_journal_get_data(j, "COREDUMP", (const void**) &data, &len); - if (r < 0) { + if (r == ENOENT) { + _cleanup_free_ char *fn = NULL; + _cleanup_close_ int fd = -1; + + r = make_coredump_path(j, &fn); + if (r < 0) + return r; + + fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) { + if (errno == ENOENT) + log_error("Coredump neither in journal file nor stored externally on disk."); + else + log_error("Failed to open coredump file: %s", strerror(-r)); + + return -errno; + } + + r = copy_bytes(fd, output ? fileno(output) : STDOUT_FILENO); + if (r < 0) { + log_error("Failed to stream coredump: %s", strerror(-r)); + return r; + } + + } else if (r < 0) { log_error("Failed to retrieve COREDUMP field: %s", strerror(-r)); return r; - } - assert(len >= 9); - data = (const uint8_t*) data + 9; - len -= 9; + } else { + assert(len >= 9); + data = (const uint8_t*) data + 9; + len -= 9; - ret = fwrite(data, len, 1, output ? output : stdout); - if (ret != 1) { - log_error("dumping coredump: %m (%zu)", ret); - return -errno; + ret = fwrite(data, len, 1, output ?: stdout); + if (ret != 1) { + log_error("Dumping coredump failed: %m (%zu)", ret); + return -errno; + } } r = sd_journal_previous(j); @@ -423,15 +500,16 @@ static int dump_core(sd_journal* j) { } static int run_gdb(sd_journal *j) { - char path[] = "/var/tmp/coredump-XXXXXX"; + + _cleanup_free_ char *exe = NULL, *coredump = NULL; + char temp[] = "/var/tmp/coredump-XXXXXX"; + bool unlink_temp = false; + const char *path; const void *data; + siginfo_t st; size_t len; - ssize_t sz; pid_t pid; - _cleanup_free_ char *exe = NULL; int r; - _cleanup_close_ int fd = -1; - siginfo_t st; assert(j); @@ -462,35 +540,63 @@ static int run_gdb(sd_journal *j) { return -ENOENT; } + if (!path_is_absolute(exe)) { + log_error("Binary is not an absolute path."); + return -ENOENT; + } + r = sd_journal_get_data(j, "COREDUMP", (const void**) &data, &len); - if (r < 0) { + if (r == -ENOENT) { + + r = make_coredump_path(j, &coredump); + if (r < 0) + return r; + + if (access(coredump, R_OK) < 0) { + if (errno == ENOENT) + log_error("Coredump neither in journal file nor stored externally on disk."); + else + log_error("Failed to access coredump fiile: %s", strerror(-r)); + + return -errno; + } + + path = coredump; + + } else if (r < 0) { log_error("Failed to retrieve COREDUMP field: %s", strerror(-r)); return r; - } - assert(len >= 9); - data = (const uint8_t*) data + 9; - len -= 9; + } else { + _cleanup_close_ int fd = -1; + ssize_t sz; - fd = mkostemp_safe(path, O_WRONLY|O_CLOEXEC); - if (fd < 0) { - log_error("Failed to create temporary file: %m"); - return -errno; - } + assert(len >= 9); + data = (const uint8_t*) data + 9; + len -= 9; - sz = write(fd, data, len); - if (sz < 0) { - log_error("Failed to write temporary file: %m"); - r = -errno; - goto finish; - } - if (sz != (ssize_t) len) { - log_error("Short write to temporary file."); - r = -EIO; - goto finish; - } + fd = mkostemp_safe(temp, O_WRONLY|O_CLOEXEC); + if (fd < 0) { + log_error("Failed to create temporary file: %m"); + return -errno; + } + + unlink_temp = true; + + sz = write(fd, data, len); + if (sz < 0) { + log_error("Failed to write temporary file: %m"); + r = -errno; + goto finish; + } + if (sz != (ssize_t) len) { + log_error("Short write to temporary file."); + r = -EIO; + goto finish; + } - fd = safe_close(fd); + path = temp; + } pid = fork(); if (pid < 0) { @@ -500,6 +606,7 @@ static int run_gdb(sd_journal *j) { } if (pid == 0) { execlp("gdb", "gdb", exe, path, NULL); + log_error("Failed to invoke gdb: %m"); _exit(1); } @@ -513,7 +620,9 @@ static int run_gdb(sd_journal *j) { r = st.si_code == CLD_EXITED ? st.si_status : 255; finish: - unlink(path); + if (unlink_temp) + unlink(temp); + return r; } -- 2.30.2