/*--------------------------------------------------------------------*/ /*--- Management of error messages. vg_errcontext.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, an extensible x86 protected-mode emulator for monitoring program execution on x86-Unixes. Copyright (C) 2000-2002 Julian Seward jseward@acm.org This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. The GNU General Public License is contained in the file COPYING. */ #include "vg_include.h" /*------------------------------------------------------------*/ /*--- Globals ---*/ /*------------------------------------------------------------*/ /* The list of error contexts found, both suppressed and unsuppressed. Initially empty, and grows as errors are detected. */ static Error* vg_errors = NULL; /* The list of suppression directives, as read from the specified suppressions file. */ static Supp* vg_suppressions = NULL; /* And a helper function so the leak detector can get hold of it. */ Supp* VG_(get_suppressions) ( void ) { return vg_suppressions; } /* Running count of unsuppressed errors detected. */ static UInt vg_n_errs_found = 0; /* Running count of suppressed errors detected. */ static UInt vg_n_errs_suppressed = 0; /* forwards ... */ static Supp* is_suppressible_error ( Error* err ); /*------------------------------------------------------------*/ /*--- Helper fns ---*/ /*------------------------------------------------------------*/ /* Compare error contexts, to detect duplicates. Note that if they are otherwise the same, the faulting addrs and associated rwoffsets are allowed to be different. */ static Bool eq_Error ( VgRes res, Error* e1, Error* e2 ) { if (e1->ekind != e2->ekind) return False; if (!VG_(eq_ExeContext)(res, e1->where, e2->where)) return False; switch (e1->ekind) { case PThreadErr: vg_assert(VG_(needs).core_errors); if (e1->string == e2->string) return True; if (0 == VG_(strcmp)(e1->string, e2->string)) return True; return False; default: if (VG_(needs).skin_errors) return SK_(eq_SkinError)(res, e1, e2); else { VG_(printf)("\nUnhandled error type: %u. VG_(needs).skin_errors\n" "probably needs to be set.\n", e1->ekind); VG_(skin_panic)("unhandled error type"); } } } static void pp_Error ( Error* err, Bool printCount ) { /* Closure for printing where the error occurred. Abstracts details about the `where' field away from the skin. */ void pp_ExeContextClosure(void) { VG_(pp_ExeContext) ( err->where ); } if (printCount) VG_(message)(Vg_UserMsg, "Observed %d times:", err->count ); if (err->tid > 1) VG_(message)(Vg_UserMsg, "Thread %d:", err->tid ); switch (err->ekind) { case PThreadErr: vg_assert(VG_(needs).core_errors); VG_(message)(Vg_UserMsg, "%s", err->string ); VG_(pp_ExeContext)(err->where); break; default: if (VG_(needs).skin_errors) SK_(pp_SkinError)( err, &pp_ExeContextClosure ); else { VG_(printf)("\nUnhandled error type: %u. VG_(needs).skin_errors\n" "probably needs to be set?\n", err->ekind); VG_(skin_panic)("unhandled error type"); } } } /* Figure out if we want to attach for GDB for this error, possibly by asking the user. */ static Bool vg_is_GDB_attach_requested ( void ) { Char ch, ch2; Int res; if (VG_(clo_GDB_attach) == False) return False; VG_(message)(Vg_UserMsg, ""); again: VG_(printf)( "==%d== " "---- Attach to GDB ? --- [Return/N/n/Y/y/C/c] ---- ", VG_(getpid)() ); res = VG_(read)(0 /*stdin*/, &ch, 1); if (res != 1) goto ioerror; /* res == 1 */ if (ch == '\n') return False; if (ch != 'N' && ch != 'n' && ch != 'Y' && ch != 'y' && ch != 'C' && ch != 'c') goto again; res = VG_(read)(0 /*stdin*/, &ch2, 1); if (res != 1) goto ioerror; if (ch2 != '\n') goto again; /* No, don't want to attach. */ if (ch == 'n' || ch == 'N') return False; /* Yes, want to attach. */ if (ch == 'y' || ch == 'Y') return True; /* No, don't want to attach, and don't ask again either. */ vg_assert(ch == 'c' || ch == 'C'); ioerror: VG_(clo_GDB_attach) = False; return False; } /* I've gone all object-oriented... initialisation depends on where the error comes from: - If from generated code (tst == NULL), the %EIP/%EBP values that we need in order to create proper error messages are picked up out of VG_(baseBlock) rather than from the thread table (vg_threads in vg_scheduler.c). - If not from generated code but in response to requests passed back to the scheduler (tst != NULL), we pick up %EIP/%EBP values from the stored thread state, not from VG_(baseBlock). */ static __inline__ void construct_error ( Error* err, ThreadState* tst, ErrorKind ekind, Addr a, Char* s, void* extra ) { /* Core-only parts */ err->next = NULL; err->supp = NULL; err->count = 1; err->where = VG_(get_ExeContext)( tst ); if (NULL == tst) { err->tid = VG_(get_current_tid)(); err->m_eip = VG_(baseBlock)[VGOFF_(m_eip)]; err->m_esp = VG_(baseBlock)[VGOFF_(m_esp)]; err->m_ebp = VG_(baseBlock)[VGOFF_(m_ebp)]; } else { err->tid = tst->tid; err->m_eip = tst->m_eip; err->m_esp = tst->m_esp; err->m_ebp = tst->m_ebp; } /* Skin-relevant parts */ err->ekind = ekind; err->addr = a; err->string = s; err->extra = extra; /* sanity... */ vg_assert(err->tid >= 0 && err->tid < VG_N_THREADS); } /* Top-level entry point to the error management subsystem. All detected errors are notified here; this routine decides if/when the user should see the error. */ void VG_(maybe_record_error) ( ThreadState* tst, ErrorKind ekind, Addr a, Char* s, void* extra ) { Error err; Error* p; Error* p_prev; VgRes exe_res = Vg_MedRes; static Bool is_first_shown_context = True; static Bool stopping_message = False; static Bool slowdown_message = False; static Int vg_n_errs_shown = 0; /* After M_VG_COLLECT_NO_ERRORS_AFTER_SHOWN different errors have been found, or M_VG_COLLECT_NO_ERRORS_AFTER_FOUND total errors have been found, just refuse to collect any more. This stops the burden of the error-management system becoming excessive in extremely buggy programs, although it does make it pretty pointless to continue the Valgrind run after this point. */ if (VG_(clo_error_limit) && (vg_n_errs_shown >= M_VG_COLLECT_NO_ERRORS_AFTER_SHOWN || vg_n_errs_found >= M_VG_COLLECT_NO_ERRORS_AFTER_FOUND)) { if (!stopping_message) { VG_(message)(Vg_UserMsg, ""); if (vg_n_errs_shown >= M_VG_COLLECT_NO_ERRORS_AFTER_SHOWN) { VG_(message)(Vg_UserMsg, "More than %d different errors detected. " "I'm not reporting any more.", M_VG_COLLECT_NO_ERRORS_AFTER_SHOWN ); } else { VG_(message)(Vg_UserMsg, "More than %d total errors detected. " "I'm not reporting any more.", M_VG_COLLECT_NO_ERRORS_AFTER_FOUND ); } VG_(message)(Vg_UserMsg, "Final error counts will be inaccurate. Go fix your program!"); VG_(message)(Vg_UserMsg, "Rerun with --error-limit=no to disable this cutoff. Note"); VG_(message)(Vg_UserMsg, "that errors may occur in your program without prior warning from"); VG_(message)(Vg_UserMsg, "Valgrind, because errors are no longer being displayed."); VG_(message)(Vg_UserMsg, ""); stopping_message = True; } return; } /* After M_VG_COLLECT_ERRORS_SLOWLY_AFTER different errors have been found, be much more conservative about collecting new ones. */ if (vg_n_errs_shown >= M_VG_COLLECT_ERRORS_SLOWLY_AFTER) { exe_res = Vg_LowRes; if (!slowdown_message) { VG_(message)(Vg_UserMsg, ""); VG_(message)(Vg_UserMsg, "More than %d errors detected. Subsequent errors", M_VG_COLLECT_ERRORS_SLOWLY_AFTER); VG_(message)(Vg_UserMsg, "will still be recorded, but in less detail than before."); slowdown_message = True; } } /* Build ourselves the error */ construct_error ( &err, tst, ekind, a, s, extra ); /* First, see if we've got an error record matching this one. */ p = vg_errors; p_prev = NULL; while (p != NULL) { if (eq_Error(exe_res, p, &err)) { /* Found it. */ p->count++; if (p->supp != NULL) { /* Deal correctly with suppressed errors. */ p->supp->count++; vg_n_errs_suppressed++; } else { vg_n_errs_found++; } /* Move p to the front of the list so that future searches for it are faster. */ if (p_prev != NULL) { vg_assert(p_prev->next == p); p_prev->next = p->next; p->next = vg_errors; vg_errors = p; } return; } p_prev = p; p = p->next; } /* Didn't see it. Copy and add. */ /* OK, we're really going to collect it. First make a copy, because the error context is on the stack and will disappear shortly. We can duplicate the main part ourselves, but use SK_(dup_extra_and_update) to duplicate the `extra' part. SK_(dup_extra_and_update) can also update the `extra' part. This is for when there are more details to fill in which take time to work out but don't affect our earlier decision to include the error -- by postponing those details until now, we avoid the extra work in the case where we ignore the error. Ugly. */ p = VG_(arena_malloc)(VG_AR_ERRORS, sizeof(Error)); *p = err; p->extra = SK_(dup_extra_and_update)(p); p->next = vg_errors; p->supp = is_suppressible_error(&err); vg_errors = p; if (p->supp == NULL) { vg_n_errs_found++; if (!is_first_shown_context) VG_(message)(Vg_UserMsg, ""); pp_Error(p, False); is_first_shown_context = False; vg_n_errs_shown++; /* Perhaps we want a GDB attach at this point? */ if (vg_is_GDB_attach_requested()) { VG_(swizzle_esp_then_start_GDB)( err.m_eip, err.m_esp, err.m_ebp); } } else { vg_n_errs_suppressed++; p->supp->count++; } } /*------------------------------------------------------------*/ /*--- Exported fns ---*/ /*------------------------------------------------------------*/ /* These are called not from generated code but from the scheduler */ void VG_(record_pthread_error) ( ThreadId tid, Char* msg ) { if (! VG_(needs).core_errors) return; VG_(maybe_record_error)( &VG_(threads)[tid], PThreadErr, /*addr*/0, msg, /*extra*/NULL ); } /*------------------------------*/ void VG_(show_all_errors) ( void ) { Int i, n_min; Int n_err_contexts, n_supp_contexts; Error *p, *p_min; Supp *su; Bool any_supp; if (VG_(clo_verbosity) == 0) return; n_err_contexts = 0; for (p = vg_errors; p != NULL; p = p->next) { if (p->supp == NULL) n_err_contexts++; } n_supp_contexts = 0; for (su = vg_suppressions; su != NULL; su = su->next) { if (su->count > 0) n_supp_contexts++; } VG_(message)(Vg_UserMsg, "ERROR SUMMARY: " "%d errors from %d contexts (suppressed: %d from %d)", vg_n_errs_found, n_err_contexts, vg_n_errs_suppressed, n_supp_contexts ); if (VG_(clo_verbosity) <= 1) return; /* Print the contexts in order of increasing error count. */ for (i = 0; i < n_err_contexts; i++) { n_min = (1 << 30) - 1; p_min = NULL; for (p = vg_errors; p != NULL; p = p->next) { if (p->supp != NULL) continue; if (p->count < n_min) { n_min = p->count; p_min = p; } } if (p_min == NULL) VG_(skin_panic)("show_all_errors()"); VG_(message)(Vg_UserMsg, ""); VG_(message)(Vg_UserMsg, "%d errors in context %d of %d:", p_min->count, i+1, n_err_contexts); pp_Error( p_min, False ); if ((i+1 == VG_(clo_dump_error))) { VG_(translate) ( 0 /* dummy ThreadId; irrelevant due to below NULLs */, p_min->where->eips[0], NULL, NULL, NULL, NULL ); } p_min->count = 1 << 30; } if (n_supp_contexts > 0) VG_(message)(Vg_DebugMsg, ""); any_supp = False; for (su = vg_suppressions; su != NULL; su = su->next) { if (su->count > 0) { any_supp = True; VG_(message)(Vg_DebugMsg, "supp: %4d %s", su->count, su->sname); } } if (n_err_contexts > 0) { if (any_supp) VG_(message)(Vg_UserMsg, ""); VG_(message)(Vg_UserMsg, "IN SUMMARY: " "%d errors from %d contexts (suppressed: %d from %d)", vg_n_errs_found, n_err_contexts, vg_n_errs_suppressed, n_supp_contexts ); VG_(message)(Vg_UserMsg, ""); } } /*------------------------------------------------------------*/ /*--- Standard suppressions ---*/ /*------------------------------------------------------------*/ /* Get a non-blank, non-comment line of at most nBuf chars from fd. Skips leading spaces on the line. Return True if EOF was hit instead. */ #define VG_ISSPACE(ch) (((ch)==' ') || ((ch)=='\n') || ((ch)=='\t')) Bool VG_(get_line) ( Int fd, Char* buf, Int nBuf ) { Char ch; Int n, i; while (True) { /* First, read until a non-blank char appears. */ while (True) { n = VG_(read)(fd, &ch, 1); if (n == 1 && !VG_ISSPACE(ch)) break; if (n == 0) return True; } /* Now, read the line into buf. */ i = 0; buf[i++] = ch; buf[i] = 0; while (True) { n = VG_(read)(fd, &ch, 1); if (n == 0) return False; /* the next call will return True */ if (ch == '\n') break; if (i > 0 && i == nBuf-1) i--; buf[i++] = ch; buf[i] = 0; } while (i > 1 && VG_ISSPACE(buf[i-1])) { i--; buf[i] = 0; }; /* VG_(printf)("The line is `%s'\n", buf); */ /* Ok, we have a line. If a non-comment line, return. If a comment line, start all over again. */ if (buf[0] != '#') return False; } } /* *p_caller contains the raw name of a caller, supposedly either fun:some_function_name or obj:some_object_name. Set *p_ty accordingly and advance *p_caller over the descriptor (fun: or obj:) part. Returns False if failed. */ static Bool setLocationTy ( Char** p_caller, SuppLocTy* p_ty ) { if (VG_(strncmp)(*p_caller, "fun:", 4) == 0) { (*p_caller) += 4; *p_ty = FunName; return True; } if (VG_(strncmp)(*p_caller, "obj:", 4) == 0) { (*p_caller) += 4; *p_ty = ObjName; return True; } VG_(printf)("location should start with fun: or obj:\n"); return False; } /* Look for "skin" in a string like "skin1,skin2,skin3" */ static __inline__ Bool skin_name_present(Char *name, Char *names) { Bool found; Char *s = NULL; /* Shut gcc up */ Int len = VG_(strlen)(name); found = (NULL != (s = VG_(strstr)(names, name)) && (s == names || *(s-1) == ',') && (*(s+len) == ',' || *(s+len) == '\0') ); return found; } #define STREQ(s1,s2) (s1 != NULL && s2 != NULL \ && VG_(strcmp)((s1),(s2))==0) /* Read suppressions from the file specified in vg_clo_suppressions and place them in the suppressions list. If there's any difficulty doing this, just give up -- there's no point in trying to recover. */ static void load_one_suppressions_file ( Char* filename ) { # define N_BUF 200 Int fd, i; Bool eof; Char buf[N_BUF+1]; Char* skin_names; Char* supp_name; fd = VG_(open)( filename, VKI_O_RDONLY, 0 ); if (fd == -1) { VG_(message)(Vg_UserMsg, "FATAL: can't open suppressions file `%s'", filename ); VG_(exit)(1); } while (True) { /* Assign and initialise the two suppression halves (core and skin) */ Supp* supp; supp = VG_(arena_malloc)(VG_AR_CORE, sizeof(Supp)); supp->count = 0; for (i = 0; i < VG_N_SUPP_CALLERS; i++) supp->caller[i] = NULL; supp->string = supp->extra = NULL; eof = VG_(get_line) ( fd, buf, N_BUF ); if (eof) break; if (!STREQ(buf, "{")) goto syntax_error; eof = VG_(get_line) ( fd, buf, N_BUF ); if (eof || STREQ(buf, "}")) goto syntax_error; supp->sname = VG_(arena_strdup)(VG_AR_CORE, buf); eof = VG_(get_line) ( fd, buf, N_BUF ); if (eof) goto syntax_error; /* Check it has the "skin1,skin2,...:supp" form (look for ':') */ i = 0; while (True) { if (buf[i] == ':') break; if (buf[i] == '\0') goto syntax_error; i++; } buf[i] = '\0'; /* Replace ':', splitting into two strings */ skin_names = & buf[0]; supp_name = & buf[i+1]; /* Is it a core suppression? */ if (VG_(needs).core_errors && skin_name_present("core", skin_names)) { if (STREQ(supp_name, "PThread")) supp->skind = PThreadSupp; else goto syntax_error; } /* Is it a skin suppression? */ else if (VG_(needs).skin_errors && skin_name_present(VG_(details).name, skin_names)) { if (SK_(recognised_suppression)(supp_name, supp)) { /* Do nothing, function fills in supp->skind */ } else goto syntax_error; } else { /* Ignore rest of suppression */ while (True) { eof = VG_(get_line) ( fd, buf, N_BUF ); if (eof) goto syntax_error; if (STREQ(buf, "}")) break; } continue; } if (VG_(needs).skin_errors && !SK_(read_extra_suppression_info)(fd, buf, N_BUF, supp)) goto syntax_error; /* "i > 0" ensures at least one caller read. */ for (i = 0; i < VG_N_SUPP_CALLERS; i++) { eof = VG_(get_line) ( fd, buf, N_BUF ); if (eof) goto syntax_error; if (i > 0 && STREQ(buf, "}")) break; supp->caller[i] = VG_(arena_strdup)(VG_AR_CORE, buf); if (!setLocationTy(&(supp->caller[i]), &(supp->caller_ty[i]))) goto syntax_error; } supp->next = vg_suppressions; vg_suppressions = supp; } VG_(close)(fd); return; syntax_error: if (eof) { VG_(message)(Vg_UserMsg, "FATAL: in suppressions file `%s': unexpected EOF", filename ); } else { VG_(message)(Vg_UserMsg, "FATAL: in suppressions file: `%s': syntax error on: %s", filename, buf ); } VG_(close)(fd); VG_(message)(Vg_UserMsg, "exiting now."); VG_(exit)(1); # undef N_BUF } void VG_(load_suppressions) ( void ) { Int i; vg_suppressions = NULL; for (i = 0; i < VG_(clo_n_suppressions); i++) { if (VG_(clo_verbosity) > 1) { VG_(message)(Vg_UserMsg, "Reading suppressions file: %s", VG_(clo_suppressions)[i] ); } load_one_suppressions_file( VG_(clo_suppressions)[i] ); } } /* Return the name of an erring fn in a way which is useful for comparing against the contents of a suppressions file. Doesn't demangle the fn name, because we want to refer to mangled names in the suppressions file. */ void VG_(get_objname_fnname) ( Addr a, Char* obj_buf, Int n_obj_buf, Char* fun_buf, Int n_fun_buf ) { (void)VG_(get_objname) ( a, obj_buf, n_obj_buf ); (void)VG_(get_fnname_nodemangle)( a, fun_buf, n_fun_buf ); } static __inline__ Bool supp_matches_error(Supp* su, Error* err) { switch (su->skind) { case PThreadSupp: return (err->ekind == PThreadErr); default: if (VG_(needs).skin_errors) { return SK_(error_matches_suppression)(err, su); } else { VG_(printf)( "\nUnhandled suppression type: %u. VG_(needs).skin_errors\n" "probably needs to be set.\n", err->ekind); VG_(skin_panic)("unhandled suppression type"); } } } static __inline__ Bool supp_matches_callers(Supp* su, Char caller_obj[][M_VG_ERRTXT], Char caller_fun[][M_VG_ERRTXT]) { Int i; for (i = 0; su->caller[i] != NULL; i++) { switch (su->caller_ty[i]) { case ObjName: if (VG_(string_match)(su->caller[i], caller_obj[i])) break; return False; case FunName: if (VG_(string_match)(su->caller[i], caller_fun[i])) break; return False; default: VG_(skin_panic)("is_suppressible_error"); } } /* If we reach here, it's a match */ return True; } /* Does an error context match a suppression? ie is this a suppressible error? If so, return a pointer to the Supp record, otherwise NULL. Tries to minimise the number of symbol searches since they are expensive. */ static Supp* is_suppressible_error ( Error* err ) { Int i; Char caller_obj[VG_N_SUPP_CALLERS][M_VG_ERRTXT]; Char caller_fun[VG_N_SUPP_CALLERS][M_VG_ERRTXT]; Supp* su; /* get_objname_fnname() writes the function name and object name if it finds them in the debug info. so the strings in the suppression file should match these. */ /* Initialise these strs so they are always safe to compare, even if get_objname_fnname doesn't write anything to them. */ for (i = 0; i < VG_N_SUPP_CALLERS; i++) caller_obj[i][0] = caller_fun[i][0] = 0; for (i = 0; i < VG_N_SUPP_CALLERS && i < VG_(clo_backtrace_size); i++) { VG_(get_objname_fnname) ( err->where->eips[i], caller_obj[i], M_VG_ERRTXT, caller_fun[i], M_VG_ERRTXT ); } /* See if the error context matches any suppression. */ for (su = vg_suppressions; su != NULL; su = su->next) { if (supp_matches_error(su, err) && supp_matches_callers(su, caller_obj, caller_fun)) { return su; } } return NULL; /* no matches */ } #undef STREQ /*--------------------------------------------------------------------*/ /*--- end vg_errcontext.c ---*/ /*--------------------------------------------------------------------*/