diff options
| -rw-r--r-- | src/readelf.c | 164 |
1 files changed, 160 insertions, 4 deletions
diff --git a/src/readelf.c b/src/readelf.c index efb445ed..11082830 100644 --- a/src/readelf.c +++ b/src/readelf.c @@ -57,6 +57,18 @@ #include "../libdw/known-dwarf.h" +#ifdef USE_LOCKS +#include "threadlib.h" +#endif + +#ifdef HAVE_SCHED_H +#include <sched.h> +#endif + +#ifdef HAVE_SYS_RESOURCE_H +#include <sys/resource.h> +#endif + #ifdef __linux__ #define CORE_SIGILL SIGILL #define CORE_SIGBUS SIGBUS @@ -150,6 +162,10 @@ static const struct argp_option options[] = N_("Ignored for compatibility (lines always wide)"), 0 }, { "decompress", 'z', NULL, 0, N_("Show compression information for compressed sections (when used with -S); decompress section before dumping data (when used with -p or -x)"), 0 }, +#ifdef USE_LOCKS + { "concurrency", 'C', "NUM", 0, + N_("Set maximum number of threads. Defaults to the number of CPUs."), 0 }, +#endif { NULL, 0, NULL, 0, NULL, 0 } }; @@ -249,6 +265,11 @@ static bool print_decompress = false; /* True if we want to show split compile units for debug_info skeletons. */ static bool show_split_units = false; +#if USE_LOCKS +/* Maximum number of threads. */ +static int max_threads = 0; +#endif + /* Select printing of debugging sections. */ static enum section_e { @@ -380,6 +401,43 @@ cleanup_list (struct section_argument *list) } } +#ifdef USE_LOCKS +/* Estimate the maximum number of threads. This is normally + #CPU. Return value is guaranteed to be at least 1. */ +static int +default_concurrency (void) +{ + unsigned aff = 0; +#ifdef HAVE_SCHED_GETAFFINITY + { + int ret; + cpu_set_t mask; + CPU_ZERO (&mask); + ret = sched_getaffinity (0, sizeof(mask), &mask); + if (ret == 0) + aff = CPU_COUNT (&mask); + } +#endif + + unsigned fn = 0; +#ifdef HAVE_GETRLIMIT + { + struct rlimit rlim; + int rc = getrlimit (RLIMIT_NOFILE, &rlim); + if (rc == 0) + fn = MAX ((rlim_t) 1, (rlim.rlim_cur - 100) / 2); + /* Conservatively estimate that at least 2 fds are used + by each thread. */ + } +#endif + + unsigned d = MIN (MAX (aff, 2U), + MAX (fn, 2U)); + + return d; +} +#endif + int main (int argc, char *argv[]) { @@ -403,6 +461,12 @@ main (int argc, char *argv[]) /* Before we start tell the ELF library which version we are using. */ elf_version (EV_CURRENT); +#ifdef USE_LOCKS + /* If concurrency wasn't set by argp_parse, then set a default value. */ + if (max_threads == 0) + max_threads = default_concurrency (); +#endif + /* Now process all the files given at the command line. */ bool only_one = remaining + 1 == argc; do @@ -527,6 +591,19 @@ parse_opt (int key, char *arg, case 'c': print_archive_index = true; break; +#if USE_LOCKS + case 'C': + if (arg != NULL) + { + max_threads = atoi (arg); + if (max_threads < 1) + { + argp_error (state, _("-C NUM minimum 1")); + return EINVAL; + } + } + break; +#endif case 'w': if (arg == NULL) { @@ -5496,7 +5573,7 @@ listptr_base (struct listptr *p) } /* To store the name used in compare_listptr */ -static const char *sort_listptr_name; +_Thread_local const char *sort_listptr_name; static int compare_listptr (const void *a, const void *b) @@ -11997,6 +12074,65 @@ getone_dwflmod (Dwfl_Module *dwflmod, return DWARF_CB_OK; } +typedef struct { + Dwfl_Module *dwflmod; + Ebl *ebl; + GElf_Ehdr *ehdr; + Elf_Scn scn; + GElf_Shdr shdr; + Dwarf *dbg; + FILE *out; + void (*fp) (Dwfl_Module *, Ebl *, GElf_Ehdr *, + Elf_Scn *, GElf_Shdr *, Dwarf *, FILE *); +} job_data; + +#ifdef USE_LOCKS + +/* Thread entry point. */ +static void * +do_job (void *data, FILE *out) +{ + job_data *d = (job_data *) data; + d->fp (d->dwflmod, d->ebl, d->ehdr, &d->scn, &d->shdr, d->dbg, out); + return NULL; +} +#endif + +/* If readelf is built with thread safety, then set up JDATA at index IDX + and add it to the job queue. + + If thread safety is not supported or the maximum number of threads is set + to 1, then immediately call START_ROUTINE with the given arguments. */ +static void +schedule_job (job_data jdata[], size_t idx, + void (*start_routine) (Dwfl_Module *, Ebl *, GElf_Ehdr *, + Elf_Scn *, GElf_Shdr *, Dwarf *, FILE *), + Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn *scn, + GElf_Shdr *shdr, Dwarf *dbg) +{ +#ifdef USE_LOCKS + if (max_threads > 1) + { + /* Add to the job queue. */ + jdata[idx].dwflmod = dwflmod; + jdata[idx].ebl = ebl; + jdata[idx].ehdr = ehdr; + jdata[idx].scn = *scn; + jdata[idx].shdr = *shdr; + jdata[idx].dbg = dbg; + jdata[idx].fp = start_routine; + + add_job (do_job, (void *) &jdata[idx]); + } + else + start_routine (dwflmod, ebl, ehdr, scn, shdr, dbg, stdout); +#else + (void) jdata; (void) idx; + + start_routine (dwflmod, ebl, ehdr, scn, shdr, dbg, stdout); +#endif +} + static void print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr) { @@ -12169,6 +12305,9 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr) if (unlikely (elf_getshdrstrndx (ebl->elf, &shstrndx) < 0)) error_exit (0, _("cannot get section header string table index")); + size_t num_jobs = 0; + job_data *jdata = NULL; + /* If the .debug_info section is listed as implicitly required then we must make sure to handle it before handling any other debug section. Various other sections depend on the CU DIEs being @@ -12266,6 +12405,13 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr) if (name == NULL) continue; + if (jdata == NULL) + { + jdata = calloc (ndebug_sections, sizeof (*jdata)); + if (jdata == NULL) + error_exit (0, _("failed to allocate job data")); + } + int n; for (n = 0; n < ndebug_sections; ++n) { @@ -12287,17 +12433,27 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr) && strcmp (&name[14], debug_sections[n].name) == 0) ) { - if ((print_debug_sections | implicit_debug_sections) - & debug_sections[n].bitmask) - debug_sections[n].fp (dwflmod, ebl, ehdr, scn, shdr, dbg, stdout); + if (((print_debug_sections | implicit_debug_sections) + & debug_sections[n].bitmask)) + schedule_job (jdata, num_jobs++, debug_sections[n].fp, + dwflmod, ebl, ehdr, scn, shdr, dbg); + + assert (num_jobs <= ndebug_sections); break; } } } } +#ifdef USE_LOCKS + /* If max_threads <= 1, then jobs were immediately run in schedule_job. */ + if (max_threads > 1) + run_jobs (max_threads); +#endif + dwfl_end (skel_dwfl); free (skel_name); + free (jdata); /* Turn implicit and/or explicit back on in case we go over another file. */ if (implicit_info) |