diff --git a/glibc.changes b/glibc.changes index 93109ff..66e85cb 100644 --- a/glibc.changes +++ b/glibc.changes @@ -1,3 +1,9 @@ +------------------------------------------------------------------- +Tue May 4 12:19:24 UTC 2021 - Andreas Schwab + +- nptl-db-libpthread-load-order.patch: nptl_db: Support different + libpthread/ld.so load orders (bscn#1184214, BZ #27744) + ------------------------------------------------------------------- Tue Apr 13 11:44:37 UTC 2021 - Andreas Schwab diff --git a/glibc.spec b/glibc.spec index 4fe3bd4..be7f398 100644 --- a/glibc.spec +++ b/glibc.spec @@ -257,6 +257,8 @@ Patch1003: nscd-netgroupcache.patch Patch1004: nss-database-lookup.patch # PATCH-FIX-UPSTREAM linux: always update select timeout (BZ #27706) Patch1005: select-modify-timeout.patch +# PATCH-FIX-UPSTREAM: nptl_db: Support different libpthread/ld.so load orders (BZ #27744) +Patch1006: nptl-db-libpthread-load-order.patch ### # Patches awaiting upstream approval @@ -480,6 +482,7 @@ Internal usrmerge bootstrap helper %patch1003 -p1 %patch1004 -p1 %patch1005 -p1 +%patch1006 -p1 %patch2000 -p1 %patch2001 -p1 @@ -490,9 +493,6 @@ Internal usrmerge bootstrap helper # Disable LTO due to a usage of top-level assembler that # causes LTO issues (boo#1138807). %define _lto_cflags %{nil} -%if "%flavor" == "i686" -%global optflags %(echo "%optflags"|sed -e s/i586/i686/) -march=i686 -mtune=generic -%endif if [ -x /bin/uname.bin ]; then /bin/uname.bin -a else @@ -527,9 +527,15 @@ for opt in $tmp; do -fstack-protector-*) enable_stack_protector=${opt#-fstack-protector-} ;; -fstack-protector) enable_stack_protector=yes ;; -ffortify=* | *_FORTIFY_SOURCE*) ;; +%if "%flavor" == "i686" + *i586*) BuildFlags+=" ${opt/i586/i686}" ;; +%endif *) BuildFlags+=" $opt" ;; esac done +%if "%flavor" == "i686" +BuildFlags+=" -march=i686 -mtune=generic" +%endif BuildCC="%__cc" BuildCCplus="%__cxx" # diff --git a/nptl-db-libpthread-load-order.patch b/nptl-db-libpthread-load-order.patch new file mode 100644 index 0000000..3b644e8 --- /dev/null +++ b/nptl-db-libpthread-load-order.patch @@ -0,0 +1,380 @@ +From a64afc225240b2b27129ccfb0516d7c958b98040 Mon Sep 17 00:00:00 2001 +From: Florian Weimer +Date: Wed, 21 Apr 2021 11:50:43 +0200 +Subject: [PATCH] nptl_db: Support different libpthread/ld.so load orders (bug + 27744) + +libthread_db is loaded once GDB encounters libpthread, and at this +point, ld.so may not have been processed by GDB yet. As a result, +_rtld_global cannot be accessed by regular means from libthread_db. +To make this work until GDB can be fixed, acess _rtld_global through +a pointer stored in libpthread. + +The new test does not reproduce bug 27744 with +--disable-hardcoded-path-in-tests, but is still a valid smoke test. +With --enable-hardcoded-path-in-tests, it is necessary to avoid +add-symbol-file because this can tickle a GDB bug. + +Fixes commit 1daccf403b1bd86370eb94edca794dc106d02039 ("nptl: Move +stack list variables into _rtld_global"). + +Tested-by: Emil Velikov +--- + nptl/Makefile | 19 +++- + nptl/pthread_create.c | 8 ++ + nptl/tst-pthread-gdb-attach-static.c | 1 + + nptl/tst-pthread-gdb-attach.c | 143 +++++++++++++++++++++++++++ + nptl_db/structs.def | 3 +- + nptl_db/td_init.c | 15 +-- + nptl_db/thread_dbP.h | 2 + + 7 files changed, 180 insertions(+), 11 deletions(-) + create mode 100644 nptl/tst-pthread-gdb-attach-static.c + create mode 100644 nptl/tst-pthread-gdb-attach.c + +Index: glibc-2.33/nptl/Makefile +=================================================================== +--- glibc-2.33.orig/nptl/Makefile ++++ glibc-2.33/nptl/Makefile +@@ -294,7 +294,8 @@ tests = tst-attr2 tst-attr3 tst-default- + tst-thread-affinity-sched \ + tst-pthread-defaultattr-free \ + tst-pthread-attr-sigmask \ +- tst-pthread-timedlock-lockloop ++ tst-pthread-timedlock-lockloop \ ++ tst-pthread-gdb-attach tst-pthread-gdb-attach-static + + tests-container = tst-pthread-getattr + +@@ -344,6 +345,22 @@ CPPFLAGS-test-cond-printers.c := $(CFLAG + CPPFLAGS-test-rwlockattr-printers.c := $(CFLAGS-printers-tests) + CPPFLAGS-test-rwlock-printers.c := $(CFLAGS-printers-tests) + ++# Reuse the CFLAGS setting for the GDB attaching test. It needs ++# debugging information. ++CFLAGS-tst-pthread-gdb-attach.c := $(CFLAGS-printers-tests) ++CPPFLAGS-tst-pthread-gdb-attach.c := $(CFLAGS-printers-tests) ++ifeq ($(build-shared)$(build-hardcoded-path-in-tests),yesno) ++CPPFLAGS-tst-pthread-gdb-attach.c += -DDO_ADD_SYMBOL_FILE=1 ++else ++CPPFLAGS-tst-pthread-gdb-attach.c += -DDO_ADD_SYMBOL_FILE=0 ++endif ++CFLAGS-tst-pthread-gdb-attach-static.c := $(CFLAGS-printers-tests) ++CPPFLAGS-tst-pthread-gdb-attach-static.c := \ ++ $(CFLAGS-printers-tests) -DDO_ADD_SYMBOL_FILE=0 ++# As of version 9.2, GDB cannot attach properly to PIE programs that ++# were launched with an explicit ld.so invocation. ++tst-pthread-gdb-attach-no-pie = yes ++ + ifeq ($(build-shared),yes) + tests-printers-libs := $(shared-thread-library) + else +@@ -415,7 +432,8 @@ link-libc-static := $(common-objpfx)libc + tests-static += tst-stackguard1-static \ + tst-cancel24-static \ + tst-mutex8-static tst-mutexpi8-static tst-sem11-static \ +- tst-sem12-static tst-cond11-static ++ tst-sem12-static tst-cond11-static \ ++ tst-pthread-gdb-attach-static + + tests += tst-cancel24-static + +Index: glibc-2.33/nptl/pthread_create.c +=================================================================== +--- glibc-2.33.orig/nptl/pthread_create.c ++++ glibc-2.33/nptl/pthread_create.c +@@ -51,6 +51,14 @@ static td_thr_events_t __nptl_threads_ev + /* Pointer to descriptor with the last event. */ + static struct pthread *__nptl_last_event __attribute_used__; + ++#ifdef SHARED ++/* This variable is used to access _rtld_global from libthread_db. If ++ GDB loads libpthread before ld.so, it is not possible to resolve ++ _rtld_global directly during libpthread initialization. */ ++static struct rtld_global *__nptl_rtld_global __attribute_used__ ++ = &_rtld_global; ++#endif ++ + /* Number of threads running. */ + unsigned int __nptl_nthreads = 1; + +Index: glibc-2.33/nptl/tst-pthread-gdb-attach-static.c +=================================================================== +--- /dev/null ++++ glibc-2.33/nptl/tst-pthread-gdb-attach-static.c +@@ -0,0 +1 @@ ++#include "tst-pthread-gdb-attach.c" +Index: glibc-2.33/nptl/tst-pthread-gdb-attach.c +=================================================================== +--- /dev/null ++++ glibc-2.33/nptl/tst-pthread-gdb-attach.c +@@ -0,0 +1,217 @@ ++/* Smoke testing GDB process attach with thread-local variable access. ++ Copyright (C) 2021 Free Software Foundation, Inc. ++ This file is part of the GNU C Library. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library 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 ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ . */ ++ ++/* This test runs GDB against a forked copy of itself, to check ++ whether libthread_db can be loaded, and that access to thread-local ++ variables works. */ ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++/* Starts out as zero, changed to 1 or 2 by the debugger, depending on ++ the thread. */ ++__thread volatile int altered_by_debugger; ++ ++/* Common prefix between 32-bit and 64-bit ELF. */ ++struct elf_prefix ++{ ++ unsigned char e_ident[EI_NIDENT]; ++ uint16_t e_type; ++ uint16_t e_machine; ++ uint32_t e_version; ++}; ++_Static_assert (sizeof (struct elf_prefix) == EI_NIDENT + 8, ++ "padding in struct elf_prefix"); ++ ++/* Reads the ELF header from PATH. Returns true if the header can be ++ read, false if the file is too short. */ ++static bool ++read_elf_header (const char *path, struct elf_prefix *elf) ++{ ++ int fd = xopen (path, O_RDONLY, 0); ++ bool result = read (fd, elf, sizeof (*elf)) == sizeof (*elf); ++ xclose (fd); ++ return result; ++} ++ ++/* Searches for "gdb" alongside the path variable. See execvpe. */ ++static char * ++find_gdb (void) ++{ ++ const char *path = getenv ("PATH"); ++ if (path == NULL) ++ return NULL; ++ while (true) ++ { ++ const char *colon = strchrnul (path, ':'); ++ char *candidate = xasprintf ("%.*s/gdb", (int) (colon - path), path); ++ if (access (candidate, X_OK) == 0) ++ return candidate; ++ free (candidate); ++ if (*colon == '\0') ++ break; ++ path = colon + 1; ++ } ++ return NULL; ++} ++ ++/* Writes the GDB script to run the test to PATH. */ ++static void ++write_gdbscript (const char *path, int tested_pid) ++{ ++ FILE *fp = xfopen (path, "w"); ++ fprintf (fp, ++ "set trace-commands on\n" ++ "set debug libthread-db 1\n" ++#if DO_ADD_SYMBOL_FILE ++ /* Do not do this unconditionally to work around a GDB ++ assertion failure: ../../gdb/symtab.c:6404: ++ internal-error: CORE_ADDR get_msymbol_address(objfile*, ++ const minimal_symbol*): Assertion `(objf->flags & ++ OBJF_MAINLINE) == 0' failed. */ ++ "add-symbol-file %1$s/nptl/tst-pthread-gdb-attach\n" ++#endif ++ "set auto-load safe-path %1$s/nptl_db\n" ++ "set libthread-db-search-path %1$s/nptl_db\n" ++ "attach %2$d\n", ++ support_objdir_root, tested_pid); ++ fputs ("break debugger_inspection_point\n" ++ "continue\n" ++ "thread 1\n" ++ "print altered_by_debugger\n" ++ "print altered_by_debugger = 1\n" ++ "thread 2\n" ++ "print altered_by_debugger\n" ++ "print altered_by_debugger = 2\n" ++ "continue\n", ++ fp); ++ xfclose (fp); ++} ++ ++/* The test sets a breakpoint on this function and alters the ++ altered_by_debugger thread-local variable. */ ++void __attribute__ ((weak)) ++debugger_inspection_point (void) ++{ ++} ++ ++/* Thread function for the test thread in the subprocess. */ ++static void * ++subprocess_thread (void *closure) ++{ ++ /* Wait until altered_by_debugger changes the value away from 0. */ ++ while (altered_by_debugger == 0) ++ { ++ usleep (100 * 1000); ++ debugger_inspection_point (); ++ } ++ ++ TEST_COMPARE (altered_by_debugger, 2); ++ return NULL; ++} ++ ++/* This function implements the subprocess under test. It creates a ++ second thread, waiting for its value to change to 2, and checks ++ that the main thread also changed its value to 1. */ ++static void ++in_subprocess (void) ++{ ++ pthread_t thr = xpthread_create (NULL, subprocess_thread, NULL); ++ TEST_VERIFY (xpthread_join (thr) == NULL); ++ TEST_COMPARE (altered_by_debugger, 1); ++ _exit (0); ++} ++ ++static int ++do_test (void) ++{ ++ char *gdb_path = find_gdb (); ++ if (gdb_path == NULL) ++ FAIL_UNSUPPORTED ("gdb command not found in PATH: %s", getenv ("PATH")); ++ ++ /* Check that libthread_db is compatible with the gdb architecture ++ because gdb loads it via dlopen. */ ++ { ++ char *threaddb_path = xasprintf ("%s/nptl_db/libthread_db.so", ++ support_objdir_root); ++ struct elf_prefix elf_threaddb; ++ TEST_VERIFY_EXIT (read_elf_header (threaddb_path, &elf_threaddb)); ++ struct elf_prefix elf_gdb; ++ /* If the ELF header cannot be read or "gdb" is not an ELF file, ++ assume this is a wrapper script that can run. */ ++ if (read_elf_header (gdb_path, &elf_gdb) ++ && memcmp (&elf_gdb, ELFMAG, SELFMAG) == 0) ++ { ++ if (elf_gdb.e_ident[EI_CLASS] != elf_threaddb.e_ident[EI_CLASS]) ++ FAIL_UNSUPPORTED ("GDB at %s has wrong class", gdb_path); ++ if (elf_gdb.e_ident[EI_DATA] != elf_threaddb.e_ident[EI_DATA]) ++ FAIL_UNSUPPORTED ("GDB at %s has wrong data", gdb_path); ++ if (elf_gdb.e_machine != elf_threaddb.e_machine) ++ FAIL_UNSUPPORTED ("GDB at %s has wrong machine", gdb_path); ++ } ++ free (threaddb_path); ++ } ++ ++ pid_t tested_pid = xfork (); ++ if (tested_pid == 0) ++ in_subprocess (); ++ char *tested_pid_string = xasprintf ("%d", tested_pid); ++ ++ char *gdbscript; ++ xclose (create_temp_file ("tst-pthread-gdb-attach-", &gdbscript)); ++ write_gdbscript (gdbscript, tested_pid); ++ ++ pid_t gdb_pid = xfork (); ++ if (gdb_pid == 0) ++ { ++ xdup2 (STDOUT_FILENO, STDERR_FILENO); ++ execl (gdb_path, "gdb", "-nx", "-batch", "-x", gdbscript, NULL); ++ if (errno == ENOENT) ++ _exit (EXIT_UNSUPPORTED); ++ else ++ _exit (1); ++ } ++ ++ int status; ++ TEST_COMPARE (xwaitpid (gdb_pid, &status, 0), gdb_pid); ++ if (WIFEXITED (status) && WEXITSTATUS (status) == EXIT_UNSUPPORTED) ++ /* gdb is not installed. */ ++ return EXIT_UNSUPPORTED; ++ TEST_COMPARE (status, 0); ++ TEST_COMPARE (xwaitpid (tested_pid, &status, 0), tested_pid); ++ TEST_COMPARE (status, 0); ++ ++ free (tested_pid_string); ++ free (gdbscript); ++ free (gdb_path); ++ return 0; ++} ++ ++#include +Index: glibc-2.33/nptl_db/structs.def +=================================================================== +--- glibc-2.33.orig/nptl_db/structs.def ++++ glibc-2.33/nptl_db/structs.def +@@ -100,8 +100,7 @@ DB_STRUCT_FIELD (pthread, dtvp) + #endif + + #if !(IS_IN (libpthread) && !defined SHARED) +-DB_STRUCT (rtld_global) +-DB_RTLD_VARIABLE (_rtld_global) ++DB_VARIABLE (__nptl_rtld_global) + #endif + DB_RTLD_GLOBAL_FIELD (dl_tls_dtv_slotinfo_list) + DB_RTLD_GLOBAL_FIELD (dl_stack_user) +Index: glibc-2.33/nptl_db/td_init.c +=================================================================== +--- glibc-2.33.orig/nptl_db/td_init.c ++++ glibc-2.33/nptl_db/td_init.c +@@ -33,13 +33,14 @@ td_init (void) + bool + __td_ta_rtld_global (td_thragent_t *ta) + { +- if (ta->ta_addr__rtld_global == 0 +- && td_mod_lookup (ta->ph, LD_SO, SYM__rtld_global, +- &ta->ta_addr__rtld_global) != PS_OK) ++ if (ta->ta_addr__rtld_global == 0) + { +- ta->ta_addr__rtld_global = (void*)-1; +- return false; ++ psaddr_t rtldglobalp; ++ if (DB_GET_VALUE (rtldglobalp, ta, __nptl_rtld_global, 0) == TD_OK) ++ ta->ta_addr__rtld_global = rtldglobalp; ++ else ++ ta->ta_addr__rtld_global = (void *) -1; + } +- else +- return ta->ta_addr__rtld_global != (void*)-1; ++ ++ return ta->ta_addr__rtld_global != (void *)-1; + } +Index: glibc-2.33/nptl_db/thread_dbP.h +=================================================================== +--- glibc-2.33.orig/nptl_db/thread_dbP.h ++++ glibc-2.33/nptl_db/thread_dbP.h +@@ -108,6 +108,8 @@ struct td_thragent + # undef DB_SYMBOL + # undef DB_VARIABLE + ++ psaddr_t ta_addr__rtld_global; ++ + /* The method of locating a thread's th_unique value. */ + enum + {