From 5382cfab6110741b8ba36965b30334c00d8f9409 Mon Sep 17 00:00:00 2001 From: Philippe Waroquiers Date: Tue, 15 Sep 2015 21:02:15 +0200 Subject: [PATCH] Fix PR/18564 - regression in showing __thread so extern variable Ensure tls variable address is not relocated, as the msym addr is an offset in the thread local storage of the shared library/object. --- gdb/ChangeLog | 7 +++ gdb/findvar.c | 17 +++--- gdb/printcmd.c | 13 +++-- gdb/symtab.h | 8 ++- gdb/testsuite/ChangeLog | 6 ++ gdb/testsuite/gdb.threads/tls-so_extern.c | 19 ++++++ gdb/testsuite/gdb.threads/tls-so_extern.exp | 81 ++++++++++++++++++++++++++ gdb/testsuite/gdb.threads/tls-so_extern_main.c | 47 +++++++++++++++ 8 files changed, 185 insertions(+), 13 deletions(-) create mode 100644 gdb/testsuite/gdb.threads/tls-so_extern.c create mode 100644 gdb/testsuite/gdb.threads/tls-so_extern.exp create mode 100644 gdb/testsuite/gdb.threads/tls-so_extern_main.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7b9ec9f..1e62667 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2015-09-15 Philippe Waroquiers + + * symtab.h (address_class): Document that TLS variables + are handled by LOC_UNRESOLVED. + * findvar.c (default_read_var_value): Don't relocate TLS variables. + * printcmd.c (address_info): Don't relocate TLS variables. + 2015-09-15 Pierre Langlois * aarch64-tdep.c (decode_add_sub_imm): Use debug_printf. diff --git a/gdb/findvar.c b/gdb/findvar.c index 1c077f7..fd1b9d7 100644 --- a/gdb/findvar.c +++ b/gdb/findvar.c @@ -739,14 +739,17 @@ default_read_var_value (struct symbol *var, const struct block *var_block, if (msym == NULL) error (_("No global symbol \"%s\"."), SYMBOL_LINKAGE_NAME (var)); - if (overlay_debugging) - addr = symbol_overlayed_address (BMSYMBOL_VALUE_ADDRESS (lookup_data.result), - MSYMBOL_OBJ_SECTION (lookup_data.result.objfile, - msym)); - else - addr = BMSYMBOL_VALUE_ADDRESS (lookup_data.result); - obj_section = MSYMBOL_OBJ_SECTION (lookup_data.result.objfile, msym); + /* Relocate address, unless there is no section or the variable is + a TLS variable. */ + if (obj_section == NULL + || (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0) + addr = MSYMBOL_VALUE_RAW_ADDRESS (msym); + else + addr = BMSYMBOL_VALUE_ADDRESS (lookup_data.result); + if (overlay_debugging) + addr = symbol_overlayed_address (addr, obj_section); + /* Determine address of TLS variable. */ if (obj_section && (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0) addr = target_translate_tls_address (obj_section->objfile, addr); diff --git a/gdb/printcmd.c b/gdb/printcmd.c index 5729b24..823f27b 100644 --- a/gdb/printcmd.c +++ b/gdb/printcmd.c @@ -1376,16 +1376,19 @@ address_info (char *exp, int from_tty) else { section = MSYMBOL_OBJ_SECTION (msym.objfile, msym.minsym); - load_addr = BMSYMBOL_VALUE_ADDRESS (msym); if (section && (section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0) - printf_filtered (_("a thread-local variable at offset %s " - "in the thread-local storage for `%s'"), - paddress (gdbarch, load_addr), - objfile_name (section->objfile)); + { + load_addr = MSYMBOL_VALUE_RAW_ADDRESS (msym.minsym); + printf_filtered (_("a thread-local variable at offset %s " + "in the thread-local storage for `%s'"), + paddress (gdbarch, load_addr), + objfile_name (section->objfile)); + } else { + load_addr = BMSYMBOL_VALUE_ADDRESS (msym); printf_filtered (_("static storage at address ")); fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout); if (section_is_overlay (section)) diff --git a/gdb/symtab.h b/gdb/symtab.h index 4ff8ae7..e6fc174 100644 --- a/gdb/symtab.h +++ b/gdb/symtab.h @@ -584,7 +584,13 @@ enum address_class not find it in the full symbol table. But a reference to an external symbol in a local block shadowing other definition requires full symbol without possibly having its address available for LOC_STATIC. Testcase - is provided as `gdb.dwarf2/dw2-unresolved.exp'. */ + is provided as `gdb.dwarf2/dw2-unresolved.exp'. + + This is also used for thread local storage (TLS) variables. In this case, + the address of the TLS variable must be determined when the variable is + referenced, from the MSYMBOL_VALUE_RAW_ADDRESS, which is the offset + of the TLS variable in the thread local storage of the shared + library/object. */ LOC_UNRESOLVED, diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index f56bb48..2a1f2bf 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2015-09-15 Philippe Waroquiers + + * gdb.threads/tls-so_extern.exp: New test file. + * gdb.threads/tls-so_extern.c: New test file. + * gdb.threads/tls-so_extern_main.c: New test file. + 2015-09-15 Jan Kratochvil * gdb.opt/solib-intra-step-lib.c: New file. diff --git a/gdb/testsuite/gdb.threads/tls-so_extern.c b/gdb/testsuite/gdb.threads/tls-so_extern.c new file mode 100644 index 0000000..03febeb --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-so_extern.c @@ -0,0 +1,19 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 Free Software Foundation, Inc. + + 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 3 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, see . */ + +__thread void *so_extern; +__thread void *so_extern2; diff --git a/gdb/testsuite/gdb.threads/tls-so_extern.exp b/gdb/testsuite/gdb.threads/tls-so_extern.exp new file mode 100644 index 0000000..35a55f0 --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-so_extern.exp @@ -0,0 +1,81 @@ +# Copyright 2003-2015 Free Software Foundation, Inc. + +# 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 3 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, see . */ + +# tls-so_extern.exp -- Expect script to test thread local storage in gdb, with +# a variable defined in a shared library. + +standard_testfile tls-so_extern_main.c +set libfile tls-so_extern +set srcfile_lib ${libfile}.c +set binfile_lib [standard_output_file ${libfile}.so] + + +# get the value of gcc_compiled +if [get_compiler_info] { + return -1 +} + + +if { [gdb_compile_shlib_pthreads ${srcdir}/${subdir}/${srcfile_lib} ${binfile_lib} {debug}] != "" + || [gdb_compile_pthreads ${srcdir}/${subdir}/${srcfile} ${binfile} executable [list debug shlib=${binfile_lib}]] != ""} { + return -1 +} + + +clean_restart ${binfile} +gdb_load_shlibs ${binfile_lib} + +if ![runto_main] then { + fail "Can't run to main" + return 0 +} + +gdb_test "print so_extern" "0x0" "print thread local storage variable" + +gdb_test "ptype so_extern" "void \\*" "ptype of thread local storage variable" + +gdb_test "info address so_extern" \ + "Symbol \\\"so_extern\\\" is a thread-local variable at offset 0x0 in the thread-local storage for .*tls-so_extern.*" \ + "print storage info for thread local storage variable" + +set line_number [gdb_get_line_number "break here to check result"] + +gdb_test "break $line_number" \ + "Breakpoint.*at.*file.*tls-so_extern_main.c.*line ${line_number}." \ + "break in thread function" +gdb_test "continue" \ + "tls_ptr .* at .*:.*break here to check result.*" \ + "continue to break in tls_ptr called by main" +gdb_test "print so_extern == &so_extern" \ + " = 1" \ + "check so_extern address in main" +gdb_test "continue" \ + "tls_ptr .* at .*:.*break here to check result.*" \ + "continue to break in a thread" +gdb_test "print so_extern == &so_extern" \ + " = 1" \ + "check so_extern address" +gdb_test "continue" \ + "tls_ptr .* at .*:.*break here to check result.*" \ + "continue to break in the other thread" +gdb_test "print so_extern == &so_extern" \ + " = 1" \ + "check so_extern address in other thread" +gdb_test "continue" \ + "tls_ptr .* at .*:.*break here to check result.*" \ + "continue to break in tls_ptr called at end of main" +gdb_test "print so_extern == &so_extern" \ + " = 1" \ + "check so_extern address at end of main" diff --git a/gdb/testsuite/gdb.threads/tls-so_extern_main.c b/gdb/testsuite/gdb.threads/tls-so_extern_main.c new file mode 100644 index 0000000..ab70faf --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-so_extern_main.c @@ -0,0 +1,47 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 Free Software Foundation, Inc. + + 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 3 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, see . */ + +#include + +extern __thread void *so_extern; +extern __thread void *so_extern2; + +static void * +tls_ptr (void *p) +{ + so_extern = &so_extern; + so_extern2 = &so_extern2; /* break here to check result */ +} + +int +main (void) +{ + pthread_t threads[2]; + + tls_ptr (NULL); + + pthread_create (&threads[0], NULL, tls_ptr, NULL); + pthread_create (&threads[1], NULL, tls_ptr, NULL); + + pthread_join (threads[0], NULL); + pthread_join (threads[1], NULL); + + tls_ptr (NULL); + + return 0; +} + -- 2.7.4