From: Joel Brobecker Date: Tue, 8 Dec 2015 18:04:56 +0000 (+0100) Subject: Fix regression introduced in "break *" by explicit location patches. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=305e13e67faaf940ce6eb708847a655a0735a651;p=binutils-gdb.git Fix regression introduced in "break *" by explicit location patches. A relatively recent patch support for explicit locations, and part of that patch cleaned up the way we parse breakpoint locations. Unfortunatly, a small regression crept in for "*" breakpoint locations. In particular, on PIE programs, one can see the issue by doing the following, with any program: (gdb) b *main Breakpoint 1 at 0x51a: file hello.c, line 3. (gdb) run Starting program: /[...]/hello Error in re-setting breakpoint 1: Warning: Cannot insert breakpoint 1. Cannot access memory at address 0x51a Warning: Cannot insert breakpoint 1. Cannot access memory at address 0x51a Just for the record, this regression was introduced by: commit a06efdd6effd149a1d392df8d62824e44872003a Date: Tue Aug 11 17:09:35 2015 -0700 Subject: Explicit locations: introduce address locations What happens is that the patch makes the implicit assumption that the address computed the first time is static, as if it was designed to only support litteral expressions (Eg. "*0x1234"). This allows the shortcut of not re-computing the breakpoint location's address when re-setting breakpoints. However, this does not work in general, as demonstrated in the example above. This patch plugs that hole simply by saving the original expression used to compute the address as part of the address location, so as to then re-evaluate that expression during breakpoint re-set. gdb/ChangeLog: * location.h (new_address_location): Add new parameters "addr_string" and "addr_string_len". (get_address_string_location): Add declaration. * location.c (new_address_location): Add new parameters "addr_string" and "addr_string_len". If not NULL, store a copy of the addr_string in the new location as well. (get_address_string_location): New function. (string_to_event_location): Update call to new_address_location. * linespec.c (event_location_to_sals) : Save the event location in the parser's state before passing it to convert_address_location_to_sals. * breakpoint.c (create_thread_event_breakpoint): Update call to new_address_location. (init_breakpoint_sal): Get the event location's string, if any, and use it to update call to new_address_location. * python/py-finishbreakpoint.c (bpfinishpy_init): Update call to new_address_location. * spu-tdep.c (spu_catch_start): Likewise. * config/djgpp/fnchange.lst: Add entries for gdb/testsuite/gdb.base/break-fun-addr1.c and gdb/testsuite/gdb.base/break-fun-addr2.c. gdb/testsuite/ChangeLog: * gdb.base/break-fun-addr.exp: New file. * gdb.base/break-fun-addr1.c: New file. * gdb.base/break-fun-addr2.c: New file. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0f0078ba0aa..a377a322984 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,28 @@ +2016-01-21 Joel Brobecker + + * location.h (new_address_location): Add new parameters + "addr_string" and "addr_string_len". + (get_address_string_location): Add declaration. + * location.c (new_address_location): Add new parameters + "addr_string" and "addr_string_len". If not NULL, store + a copy of the addr_string in the new location as well. + (get_address_string_location): New function. + (string_to_event_location): Update call to new_address_location. + * linespec.c (event_location_to_sals) : + Save the event location in the parser's state before + passing it to convert_address_location_to_sals. + * breakpoint.c (create_thread_event_breakpoint): Update call + to new_address_location. + (init_breakpoint_sal): Get the event location's string, if any, + and use it to update call to new_address_location. + * python/py-finishbreakpoint.c (bpfinishpy_init): + Update call to new_address_location. + * spu-tdep.c (spu_catch_start): Likewise. + + * config/djgpp/fnchange.lst: Add entries for + gdb/testsuite/gdb.base/break-fun-addr1.c and + gdb/testsuite/gdb.base/break-fun-addr2.c. + 2016-01-21 Yao Qi * arm-linux-tdep.c (arm_linux_sigreturn_next_pc): Add parameter diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index 077ab5ae05f..3aac26c1113 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -7798,7 +7798,7 @@ create_thread_event_breakpoint (struct gdbarch *gdbarch, CORE_ADDR address) b->enable_state = bp_enabled; /* location has to be used or breakpoint_re_set will delete me. */ - b->location = new_address_location (b->loc->address); + b->location = new_address_location (b->loc->address, NULL, 0); update_global_location_list_nothrow (UGLL_MAY_INSERT); @@ -9369,7 +9369,18 @@ init_breakpoint_sal (struct breakpoint *b, struct gdbarch *gdbarch, if (location != NULL) b->location = location; else - b->location = new_address_location (b->loc->address); + { + const char *addr_string = NULL; + int addr_string_len = 0; + + if (location != NULL) + addr_string = event_location_to_string (location); + if (addr_string != NULL) + addr_string_len = strlen (addr_string); + + b->location = new_address_location (b->loc->address, + addr_string, addr_string_len); + } b->filter = filter; } diff --git a/gdb/config/djgpp/fnchange.lst b/gdb/config/djgpp/fnchange.lst index 54953080815..21a80717367 100644 --- a/gdb/config/djgpp/fnchange.lst +++ b/gdb/config/djgpp/fnchange.lst @@ -407,6 +407,8 @@ @V@/gdb/testsuite/gdb.base/bitfields2.c @V@/gdb/testsuite/gdb.base/bitfiel2.c @V@/gdb/testsuite/gdb.base/bitfields2.exp @V@/gdb/testsuite/gdb.base/bitfiel2.exp @V@/gdb/testsuite/gdb.base/break-entry.exp @V@/gdb/testsuite/gdb.base/brkentry.exp +@V@/gdb/testsuite/gdb.base/break-fun-addr1.c @V@/gdb/testsuite/gdb.base/b-f-a1.c +@V@/gdb/testsuite/gdb.base/break-fun-addr2.c @V@/gdb/testsuite/gdb.base/b-f-a2.c @V@/gdb/testsuite/gdb.base/coremaker2.c @V@/gdb/testsuite/gdb.base/core2maker.c @V@/gdb/testsuite/gdb.base/hashline1.exp @V@/gdb/testsuite/gdb.base/hash1line.exp @V@/gdb/testsuite/gdb.base/hashline2.exp @V@/gdb/testsuite/gdb.base/hash2line.exp diff --git a/gdb/linespec.c b/gdb/linespec.c index 588ad834611..2360cc14faf 100644 --- a/gdb/linespec.c +++ b/gdb/linespec.c @@ -2512,9 +2512,27 @@ event_location_to_sals (linespec_parser *parser, break; case ADDRESS_LOCATION: - result - = convert_address_location_to_sals (PARSER_STATE (parser), - get_address_location (location)); + { + const char *addr_string = get_address_string_location (location); + CORE_ADDR addr = get_address_location (location); + + if (addr_string != NULL) + { + char *expr = xstrdup (addr_string); + const char *const_expr = expr; + struct cleanup *cleanup = make_cleanup (xfree, expr); + + addr = linespec_expression_to_pc (&const_expr); + if (PARSER_STATE (parser)->canonical != NULL) + PARSER_STATE (parser)->canonical->location + = copy_event_location (location); + + do_cleanups (cleanup); + } + + result = convert_address_location_to_sals (PARSER_STATE (parser), + addr); + } break; case EXPLICIT_LOCATION: diff --git a/gdb/location.c b/gdb/location.c index 37285f351e8..e43ebf19feb 100644 --- a/gdb/location.c +++ b/gdb/location.c @@ -113,13 +113,16 @@ get_linespec_location (const struct event_location *location) /* See description in location.h. */ struct event_location * -new_address_location (CORE_ADDR addr) +new_address_location (CORE_ADDR addr, const char *addr_string, + int addr_string_len) { struct event_location *location; location = XCNEW (struct event_location); EL_TYPE (location) = ADDRESS_LOCATION; EL_ADDRESS (location) = addr; + if (addr_string != NULL) + EL_STRING (location) = xstrndup (addr_string, addr_string_len); return location; } @@ -134,6 +137,15 @@ get_address_location (const struct event_location *location) /* See description in location.h. */ +const char * +get_address_string_location (const struct event_location *location) +{ + gdb_assert (EL_TYPE (location) == ADDRESS_LOCATION); + return EL_STRING (location); +} + +/* See description in location.h. */ + struct event_location * new_probe_location (const char *probe) { @@ -635,7 +647,7 @@ string_to_event_location (char **stringp, orig = arg = *stringp; addr = linespec_expression_to_pc (&arg); - location = new_address_location (addr); + location = new_address_location (addr, orig, arg - orig); *stringp += arg - orig; } else diff --git a/gdb/location.h b/gdb/location.h index bc538845b38..b2cf45e495c 100644 --- a/gdb/location.h +++ b/gdb/location.h @@ -126,11 +126,14 @@ extern struct event_location * extern const char * get_linespec_location (const struct event_location *location); -/* Create a new address location. The return result is malloc'd - and should be freed with delete_event_location. */ +/* Create a new address location. + ADDR is the address corresponding to this event_location. + ADDR_STRING, a string of ADDR_STRING_LEN characters, is + the expression that was parsed to determine the address ADDR. */ extern struct event_location * - new_address_location (CORE_ADDR addr); + new_address_location (CORE_ADDR addr, const char *addr_string, + int addr_string_len); /* Return the address location (a CORE_ADDR) of the given event_location (which must be of type ADDRESS_LOCATION). */ @@ -138,6 +141,12 @@ extern struct event_location * extern CORE_ADDR get_address_location (const struct event_location *location); +/* Return the expression (a string) that was used to compute the address + of the given event_location (which must be of type ADDRESS_LOCATION). */ + +extern const char * + get_address_string_location (const struct event_location *location); + /* Create a new probe location. The return result is malloc'd and should be freed with delete_event_location. */ diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c index bff6dba6cbd..a0513b565ec 100644 --- a/gdb/python/py-finishbreakpoint.c +++ b/gdb/python/py-finishbreakpoint.c @@ -297,7 +297,7 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs) struct cleanup *back_to; /* Set a breakpoint on the return address. */ - location = new_address_location (get_frame_pc (prev_frame)); + location = new_address_location (get_frame_pc (prev_frame), NULL, 0); back_to = make_cleanup_delete_event_location (location); create_breakpoint (python_gdbarch, location, NULL, thread, NULL, diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c index 95ca8ab868c..bf3b28912c6 100644 --- a/gdb/spu-tdep.c +++ b/gdb/spu-tdep.c @@ -2001,7 +2001,7 @@ spu_catch_start (struct objfile *objfile) /* Use a numerical address for the set_breakpoint command to avoid having the breakpoint re-set incorrectly. */ - location = new_address_location (pc); + location = new_address_location (pc, NULL, 0); back_to = make_cleanup_delete_event_location (location); create_breakpoint (get_objfile_arch (objfile), location, NULL /* cond_string */, -1 /* thread */, diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 7e6da03c94c..30883204b64 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2016-01-21 Joel Brobecker + + * gdb.base/break-fun-addr.exp: New file. + * gdb.base/break-fun-addr1.c: New file. + * gdb.base/break-fun-addr2.c: New file. + 2016-01-20 Simon Marchi * gdb.python/py-pp-maint.exp: Change/add enum flag tests. diff --git a/gdb/testsuite/gdb.base/break-fun-addr.exp b/gdb/testsuite/gdb.base/break-fun-addr.exp new file mode 100644 index 00000000000..e8bed3f248b --- /dev/null +++ b/gdb/testsuite/gdb.base/break-fun-addr.exp @@ -0,0 +1,84 @@ +# Copyright 2016 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 . + +# The purpose of this testcase is to verify that, when using a breakpoint +# location of the form "*" (Eg: "*main"), GDB is able to start +# the program and stop at the correct location. With programs built +# as PIE, this means that GDB needs to re-evaluate the location once +# the program as started, since PIE ensures that the address of all +# symbols have changed after load. +# +# PIE is not always supported by the target system, so instead of +# creating a testcase building executables with PIE, this testcase +# takes a slightly different approach. It builds a first program, +# breaks on *main, and then runs to that breakpoint. It then builds +# a second program, different from the first one, and loads that +# executable within the same GDB session. Similarly to the PIE case, +# the address of main should be different, and therefore GDB should +# recalculate it. We verify that by checking that running to that +# breakpoint still works, and that we land at the first instruction +# of that function in both cases. + +set testfile1 "break-fun-addr1" +set srcfile1 ${testfile1}.c +set binfile1 [standard_output_file ${testfile1}] + +if { [gdb_compile "${srcdir}/${subdir}/${srcfile1}" "${binfile1}" executable {debug}] != "" } { + untested "Couldn't compile ${srcfile1}" + return -1 +} + +# Start the debugger with the first executable, put a breakpoint +# on the first instruction of function "main" ("*main"), then +# run to that breakpoint. + +clean_restart ${binfile1} + +with_test_prefix "${binfile1}" { + + gdb_test "break *main" \ + "Breakpoint.*at.* file .*$srcfile1, line .*" \ + + gdb_run_cmd + gdb_test "" \ + "Breakpoint.* main \\(\\) at .*$srcfile1:.*" \ + "run to breakpoint at *main" + + # Verify also that we stopped at the start of the function... + gdb_test "p \$pc == main" " = 1" +} + +set testfile2 "break-fun-addr2" +set srcfile2 ${testfile2}.c +set binfile2 [standard_output_file ${testfile2}] + +if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {debug}] != "" } { + untested "Couldn't compile ${srcfile2}" + return -1 +} + +# Now, keeping the same GDB process (so as to keep the same breakpoint), +# start a new debugging session with a different executable. +gdb_load ${binfile2} + +with_test_prefix "${binfile2}" { + + gdb_run_cmd + gdb_test "" \ + "Breakpoint.* main \\(\\) at .*$srcfile2:.*" \ + "run to breakpoint at *main" + + gdb_test "p \$pc == main" " = 1" +} diff --git a/gdb/testsuite/gdb.base/break-fun-addr1.c b/gdb/testsuite/gdb.base/break-fun-addr1.c new file mode 100644 index 00000000000..1545b21709f --- /dev/null +++ b/gdb/testsuite/gdb.base/break-fun-addr1.c @@ -0,0 +1,22 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2016 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 . */ + +int +main (void) +{ + return 0; +} diff --git a/gdb/testsuite/gdb.base/break-fun-addr2.c b/gdb/testsuite/gdb.base/break-fun-addr2.c new file mode 100644 index 00000000000..13eec05a7d7 --- /dev/null +++ b/gdb/testsuite/gdb.base/break-fun-addr2.c @@ -0,0 +1,28 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2016 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 . */ + +int +compute_something (int i) +{ + return i - 1; +} + +int +main (void) +{ + return compute_something (1); +}