Jan Kratochvil [Fri, 1 Sep 2017 04:13:40 +0000 (06:13 +0200)]
PR gdb/22046: Fix T-stopped detach regression on old Linux kernels
On <=RHEL6 hosts Fedora/RHEL GDB started to 'kill -STOP' all processes it
detached. Even those not originally T-stopped. This is a Fedora-specific
patch which is based on upstream GDB's PROC_STATE_STOPPED state.
I believe (I did not verify) this patch did regress it:
commit d617208bb06bd461b52ce041d89f7127e3044762
Author: Pedro Alves <palves@redhat.com>
Date: Mon Jul 25 12:42:17 2016 +0100
linux-procfs: Introduce enum proc_state
As originally there was strstr() but now there is strcmp() and so the missing
trailing '\n' no longer matches.
made command name lookup case sensitive. However, define_command, used
when creating a user-defined command, converts the command name to
lowercase, assuming that the command name lookup works in a case
insensitive way. This causes user-defined commands with capital letters
in their name to only be callable with a lowercase version:
(gdb) define Foo
Type commands for definition of "Foo".
End with a line saying just "end".
>print 1
>end
(gdb) Foo
Undefined command: "Foo". Try "help".
(gdb) foo
$1 = 1
This patch removes that conversion to lowercase, so that the user can
call the command with the same name they provided.
gdb/ChangeLog:
* cli/cli-script.c (define_command): Don't convert command name
to lower case.
gdb/testsuite/ChangeLog:
* gdb.base/commands.exp (user_defined_command_case_sensitivity):
New proc, call it from toplevel.
Fix a commit cd6c3b4ffc4e ("New gdbarch methods breakpoint_kind_from_pc
and sw_breakpoint_from_kind") regression and restore the use of
`->placed_address' rather than `->reqstd_address' as the location for a
memory breakpoint to be inserted at. Previously
`gdbarch_breakpoint_from_pc' was used that made that adjustment in
`default_memory_insert_breakpoint' from the preinitialized value,
however with the said commit that call is gone, so the passed
`->placed_address' has to be used for the initialization.
The regression manifests itself as the inability to debug any MIPS/Linux
compressed ISA dynamic executable as GDB corrupts the dynamic loader
with one of its implicit breakpoints, causing the program to crash, as
seen for example with the `mips-linux-gnu' target, o32 ABI, MIPS16 code,
and the gdb.base/advance.exp test case:
(gdb) continue
Continuing.
Program received signal SIGBUS, Bus error.
_dl_debug_initialize (ldbase=0, ns=0) at dl-debug.c:51
51 r = &_r_debug;
(gdb) FAIL: gdb.base/advance.exp: Can't run to main
gdb/
PR breakpoints/21886
* mem-break.c (default_memory_insert_breakpoint): Use
`->placed_address' rather than `->reqstd_address' for the
breakpoint location.
Yao Qi [Tue, 25 Jul 2017 10:38:50 +0000 (11:38 +0100)]
Catch exceptions thrown from gdbarch_skip_prologue
PR 21555 is caused by the exception during the prologue analysis when re-set
a breakpoint.
(gdb) bt
#0 memory_error_message (err=TARGET_XFER_E_IO, gdbarch=0x153db50, memaddr=93824992233232) at ../../binutils-gdb/gdb/corefile.c:192
#1 0x00000000005718ed in memory_error (err=TARGET_XFER_E_IO, memaddr=memaddr@entry=93824992233232) at ../../binutils-gdb/gdb/corefile.c:220
#2 0x00000000005719d6 in read_memory_object (object=object@entry=TARGET_OBJECT_CODE_MEMORY, memaddr=93824992233232, memaddr@entry=1, myaddr=myaddr@entry=0x7fffffffd0a0 "P\333S\001", len=len@entry=1) at ../../binutils-gdb/gdb/corefile.c:259
#3 0x0000000000571c6e in read_code (len=1, myaddr=0x7fffffffd0a0 "P\333S\001", memaddr=<optimized out>) at ../../binutils-gdb/gdb/corefile.c:287
#4 read_code_unsigned_integer (memaddr=memaddr@entry=93824992233232, len=len@entry=1, byte_order=byte_order@entry=BFD_ENDIAN_LITTLE) at ../../binutils-gdb/gdb/corefile.c:362
#5 0x000000000041d4a0 in amd64_analyze_prologue (gdbarch=gdbarch@entry=0x153db50, pc=pc@entry=93824992233232, current_pc=current_pc@entry=18446744073709551615, cache=cache@entry=0x7fffffffd1e0) at ../../binutils-gdb/gdb/amd64-tdep.c:2310
#6 0x000000000041e404 in amd64_skip_prologue (gdbarch=0x153db50, start_pc=93824992233232) at ../../binutils-gdb/gdb/amd64-tdep.c:2459
#7 0x000000000067bfb0 in skip_prologue_sal (sal=sal@entry=0x7fffffffd4e0) at ../../binutils-gdb/gdb/symtab.c:3628
#8 0x000000000067c4d8 in find_function_start_sal (sym=sym@entry=0x1549960, funfirstline=1) at ../../binutils-gdb/gdb/symtab.c:3501
#9 0x000000000060999d in symbol_to_sal (result=result@entry=0x7fffffffd5f0, funfirstline=<optimized out>, sym=sym@entry=0x1549960) at ../../binutils-gdb/gdb/linespec.c:3860
....
#16 0x000000000054b733 in location_to_sals (b=b@entry=0x15792d0, location=0x157c230, search_pspace=search_pspace@entry=0x1148120, found=found@entry=0x7fffffffdc64) at ../../binutils-gdb/gdb/breakpoint.c:14211
#17 0x000000000054c1f5 in breakpoint_re_set_default (b=0x15792d0) at ../../binutils-gdb/gdb/breakpoint.c:14301
#18 0x00000000005412a9 in breakpoint_re_set_one (bint=bint@entry=0x15792d0) at ../../binutils-gdb/gdb/breakpoint.c:14412
This problem can be fixed by
- either each prologue analyzer doesn't throw exception,
- or catch the exception thrown from gdbarch_skip_prologue,
I choose the latter because the former needs to fix *every* prologue
analyzer to not throw exception.
This error can be reproduced by changing reread.exp. The test reread.exp
has already test that breakpoint can be reset correctly after the
executable is re-read. This patch extends this test by compiling test c
file with and without -fPIE.
(gdb) run ^M
The program being debugged has been started already.^M
Start it from the beginning? (y or n) y^M
x86_64/gdb/testsuite/outputs/gdb.base/reread/reread' has changed; re-reading symbols.
Error in re-setting breakpoint 1: Cannot access memory at address 0x555555554790^M
Error in re-setting breakpoint 2: Cannot access memory at address 0x555555554790^M
Starting program: /scratch/yao/gdb/build-git/x86_64/gdb/testsuite/outputs/gdb.base/reread/reread ^M
This is foo^M
[Inferior 1 (process 27720) exited normally]^M
(gdb) FAIL: gdb.base/reread.exp: opts= "-fPIE" "ldflags=-pie" : run to foo() second time (the program exited)
This patch doesn't re-indent the code, to keep the patch simple.
Yao Qi [Tue, 25 Jul 2017 09:15:25 +0000 (10:15 +0100)]
[ARM] Access FPSCR on vfpv2
GDB can fetch or store FPSCR on vfpv3, which has 32 VFP registers, but
fail to do so on vfpv2, which has 16 VFP registers. GDB code is incorrect
for vfpv2,
else if (tdep->vfp_register_count > 0
&& regno >= ARM_D0_REGNUM
&& regno <= ARM_D0_REGNUM + tdep->vfp_register_count)
while FPSCR register number is defined as ARM_D0_REGNUM + 32.
The code above uses "<=" rather than "<", in order to put FPSCR in the
range, but it is only correct when tdep->vfp_register_count is 32. On
vpfv2, it is 16, and FPSCR is out of the range, so fetch_vfp_regs or
store_vfp_regs are not called.