SFrame function info is an unsigned 8-bit field comprising of the following
(from LSB to MSB):
- 4-bits: FRE type
- 1-bit: FRE start address encoding
- 3-bits: Unused
At the moment, the most-significat 4-bits are zero (The FRE start
address encoding of SFRAME_FDE_TYPE_PCINC has a value of zero, and the upper
3-bits are unused). So the current implementation works without this patch.
To be precise, however, the fragment fixup logic is meant to fixup only the
least-significant 4-bits (i.e., only the FRE type needs to be updated
according to the function size).
This patch makes the gas implementation a bit more resilient: In the
future, when the format does evolve to make use of the currently unused
3-bits in various ways, the values in those 3-bits can be propagated
unchanged while the fragment fixup continues to update the lowermost
4-bits to indicate the selected FRE type.
ChangeLog:
* gas/gen-sframe.c (create_func_info_exp): New definition.
(output_sframe_funcdesc): Call create_func_info_exp.
* gas/sframe-opt.c (sframe_estimate_size_before_relax): The
associated fragment uses O_modulus now.
(sframe_convert_frag): Adjust the fragment fixup code according
to the new composite exp.
Define constants in sframe.h for the various limits associated with the
range of offsets that can be encoded in the start address of an SFrame
FRE. E.g., sframe_frame_row_entry_addr1 is used when start address
offset can be encoded as 1-byte unsigned value.
Update the code in gas to use these defined constants as it checks for
these limits, and remove the usage of magic numbers.
ChangeLog:
* gas/sframe-opt.c (sframe_estimate_size_before_relax):
(sframe_convert_frag): Do not use magic numbers.
* libsframe/sframe.c (sframe_calc_fre_type): Likewise.
include/ChangeLog:
* sframe.h (SFRAME_FRE_TYPE_ADDR1_LIMIT): New constant.
(SFRAME_FRE_TYPE_ADDR2_LIMIT): Likewise.
(SFRAME_FRE_TYPE_ADDR4_LIMIT): Likewise.
With the AArch64 Scalable Matrix Extension we have a new TPIDR2 register, and
it will be added to the existing NT_ARM_TLS register set. Kernel patches are
being reviewed here:
https://lore.kernel.org/linux-arm-kernel/20220818170111.351889-1-broonie@kernel.org/
From GDB's perspective, we handle it in a similar way to the existing TPIDR
register. But we need to consider cases of systems that only have TPIDR and
systems that have both TPIDR and TPIDR2.
With that in mind, the following patch adds the required code to support
TPIDR2 and turns the org.gnu.gdb.aarch64.tls feature into a
dynamically-generated target description as opposed to a static target
description containing only TPIDR.
That means we can remove the gdb/features/aarch64-tls.xml file and replace the
existing gdb/features/aarch64-tls.c auto-generated file with a new file that
dynamically generates the target description containing either TPIDR alone or
TPIDR and TPIDR2.
In the future, when *BSD's start to support this register, they can just
enable it as is being done for the AArch64 Linux target.
The core file read/write code has been updated to support TPIDR2 as well.
On GDBserver's side, there is a small change to the find_regno function to
expose a non-throwing version of it.
It always seemed strange to me how find_regno causes the whole operation to
abort if it doesn't find a particular register name. The patch moves code
from find_regno into find_regno_no_throw and makes find_regno call
find_regno_no_throw instead.
This allows us to do register name lookups to find a particular register
number without risking erroring out if nothing is found.
The patch also adjusts the feature detection code for aarch64-fbsd, since
the infrastructure is shared amongst all aarch64 targets. I haven't added
code to support TPIDR2 in aarch64-fbsd though, as I'm not sure when/if
that will happen.
Access to section data during relocation processing should be bounds
checked, as it is in bfd_perform_relocation. bfd_perform_relocation
does these checks after any special_function is called. So a reloc
special_function needs to do its own bounds checking before accessing
section data. This patch adds many such checks to the mips backend.
Checking mips relocs is not without some difficulty. See the comment
in _bfd_mips_reloc_offset_in_range. In a multitple reloc sequence
applied to the same location, relocs that may appear somewhere other
than the last one of the sequence need to be treated specially since
they apply to the addend for the next relocation rather than the
section contents. If the addend is in the section then it needs to be
checked but not when the addend is in the reloc. check_inplace
handles this situation. _bfd_mips_reloc_offset_in_range with
check_shuffle handles the case where contents are shuffled before
applying the relocation.
PR 28306
* elf32-mips.c (_bfd_mips_elf32_gprel16_reloc): Check reloc
address using _bfd_mips_reloc_offset_in_range.
(gprel32_with_gp, mips16_gprel_reloc): Likewise.
* elf64-mips.c (mips_elf64_gprel32_reloc): Likewise.
(mips16_gprel_reloc): Likewise.
* elfn32-mips.c (mips16_gprel_reloc): Likewise.
(gprel32_with_gp): Check reloc address using
bfd_reloc_offset_in_range.
* elfxx-mips.h (enum reloc_check): Define.
(_bfd_mips_reloc_offset_in_range): Declare.
* elfxx-mips.c (needs_shuffle): New function.
(_bfd_mips_elf_reloc_unshuffle, _bfd_mips_elf_reloc_shuffle): Use it.
(_bfd_mips_reloc_offset_in_range): New function.
(_bfd_mips_elf_gprel16_with_gp): Move reloc address checks to
partial_inplace handling. Use bfd_reloc_offset_in_range.
(_bfd_mips_elf_lo16_reloc): Check reloc address using
bfd_reloc_offset_in_range.
(_bfd_mips_elf_generic_reloc): Check reloc address using
_bfd_mips_reloc_offset_in_range.
(mips_elf_calculate_relocation): Check reloc address before calling
mips_elf_nullify_got_load.
(_bfd_mips_elf_check_relocs): Likewise.
(mips_elf_read_rel_addend): Add sec param, check reloc address
before reading. Adjust callers.
(mips_elf_add_lo16_rel_addend): Add sec param, adjust callers.
On powerpc64le-linux, I run into:
...
(gdb) PASS: gdb.guile/scm-symtab.exp: step out of func2
guile (print (> (sal-line (find-pc-line (frame-pc (selected-frame)))) line))^M
= #f^M
(gdb) FAIL: gdb.guile/scm-symtab.exp: test find-pc-line with resume address
...
The problem is as follows: the instructions for the call to func2 are:
...
1000070c: 39 00 00 48 bl 10000744 <func1>
10000710: 00 00 00 60 nop
10000714: 59 00 00 48 bl 1000076c <func2>
10000718: 00 00 00 60 nop
1000071c: 00 00 20 39 li r9,0
...
and the corresponding line number info is:
...
scm-symtab.c:
File name Line number Starting address View Stmt
scm-symtab.c 42 0x1000070c x
scm-symtab.c 43 0x10000714 x
scm-symtab.c 44 0x1000071c x
...
The test-case looks at the line numbers for two insns:
- the insn of the call to func2 (0x10000714), and
- the insn after that (0x10000718),
and expects the line number of the latter to be greater than the line number
of the former.
However, both insns have the same line number: 43.
Fix this by replacing ">" with ">=".
Tested on x86_64-linux and powerpc64le-linux.
When running test-case gdb.tui/tui-layout-asm-short-prog.exp on SLE-12-SP3
aarch64, I run into:
...
FAIL: gdb.tui/tui-layout-asm-short-prog.exp: check asm box contents
FAIL: gdb.tui/tui-layout-asm-short-prog.exp: check asm box contents again
...
due to:
...
(gdb) file tui-layout-asm-short-prog^M
Reading symbols from tui-layout-asm-short-prog...^M
(No debugging symbols found in tui-layout-asm-short-prog)^M
...
I managed to reproduce the same behaviour on openSUSE Leap 15.4 x86_64, by
removing the debug option.
Fix this by making the test-case unsupported if no debug info is found.
Tested on x86_64-linux.
When building GDB with the following CFLAGS and CXXFLAGS as part of
configure line:
CFLAGS=-std=gnu11 CXXFLAGS=-std=gnu++11
Then run the selftest.exp, I see:
======
Running /home/lee/dev/binutils-gdb/gdb/testsuite/gdb.gdb/selftest.exp
...
FAIL: gdb.gdb/selftest.exp: run until breakpoint at captured_main
WARNING: Couldn't test self
=== gdb Summary ===
# of unexpected failures 1
/home/lee/dev/binutils-gdb/gdb/gdb version 13.0.50.20221206-git -nw -nx
-iex "set height 0" -iex "set width 0" -data-directory
/home/lee/dev/binutils-gdb/gdb/testsuite/../data-directory
======
It is the fact that when I use the previously mentioned CFLAGS and
CXXFLAGS as part of the configuration line, the default value (-O2 -g)
is overridden, then GDB has no debug information. When there's no debug
information, GDB should not run the testcase in selftest.exp.
The root cause of this FAIL is that the $gdb_file_cmd_debug_info didn't
get the right value ("nodebug") during the gdb_file_cmd procedure.
That's because in this commit,
commit 3453e7e409
Date: Sat May 19 11:25:20 2018 -0600
Clean up "Reading symbols" output
It changed "no debugging..." to "No debugging..." which causes the above
problem. This patch only updates the corresponding pattern to fix this
issue.
With this patch applied, I see:
======
Running /home/lee/dev/binutils-gdb/gdb/testsuite/gdb.gdb/selftest.exp
...
=== gdb Summary ===
# of untested testcases 1
/home/lee/dev/binutils-gdb/gdb/gdb version 13.0.50.20221206-git -nw -nx
-iex "set height 0" -iex "set width 0" -data-directory
/home/lee/dev/binutils-gdb/gdb/testsuite/../data-directory
======
Tested on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
While playing with JIT reader I experienced GDB to crash on null-pointer
dereference when stepping through non-jitted code.
The problem was that dwarf2_frame_find_fde () assumed that all objfiles
have BFD but that's not always true. To address this problem, this
commit skips such objfiles.
To test the fix we put breakpoint in jit_function_add (). The JIT reader
does not know how unwind this function so unwinding eventually falls
back to DWARF unwinder which in turn iterates over objfiles. Since the
the code is jitted, it is guaranteed it would eventually process JIT
objfile.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Instead of using `select_frame (nullptr)` to invalidate the selected
frame, introduce a function to do that. There is no change in behavior,
but it makes the intent a bit clearer. It also allows adding an assert
in select_frame that fi is not nullptr, so it avoids passing nullptr by
mistake.
Change-Id: I61643f46bc8eca428334513ebdaadab63997bdd0
Reviewed-By: Bruno Larsen <blarsen@redhat.com>
Add KFAILs in test-case gdb.base/longjmp.exp for PR gdb/26967, covering
various ways that gdb is unable to recover the longjmp target if the libc
probe is not supported.
Tested on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Also support compressing a few more sections.
* coffgen.c (make_a_section_from_file): Rename return_section
to newsect. Don't try to be clever matching section name.
Compress .gnu.debuglto_.debug_ and .gnu.linkonce.wi. too.
Only rename debug sections when decompressing for linker.
* write.c (compress_debug): Don't set up "ob" until after
seginfo NULL check. Simplify SEC_CONTENTS test. Localise
variables. Use bfd_debug_name_to_zdebug.
Tidies:
- Move stuff from bfd-in.h and libbfd.c to compress.c
- Delete COMPRESS_DEBUG from enum compressed_debug_section_type
- Move compress_debug field out of link_info to ld_config.
Fixes:
- Correct test in bfd_convert_section_setup to use obfd flags,
not ibfd.
- Apply bfd_applicable_file_flags to compression bfd flags added
by gas and ld to the output bfd.
bfd/
* bfd-in.h (enum compressed_debug_section_type),
(struct compressed_type_tuple),
(bfd_get_compression_algorithm),
(bfd_get_compression_algorithm_name),
* libbfd.c (compressed_debug_section_names),
(bfd_get_compression_algorithm),
(bfd_get_compression_algorithm_name): Move..
* compress.c: ..to here, deleting COMPRESS_DEBUG from
enum compressed_debug_section_type.
(bfd_convert_section_setup): Test obfd flags not ibfd for
compression flags.
* elf.c (elf_fake_sections): Replace link_info->compress_debug
test with abfd->flags test.
* bfd-in2.h: Regenerate.
binutils/
* objcopy.c (copy_file): Tidy setting of bfd compress flags.
Expand comment.
gas/
* write.c (compress_debug): Test bfd compress flags rather than
flag_compress_debug.
(write_object_file): Apply bfd_applicable_file_flags to compress
debug flags added to output bfd.
include/
* bfdlink.h (struct bfd_link_info): Delete compress_debug.
ld/
* ld.h (ld_config_type): Add compress_debug.
* emultempl/elf.em: Replace references to link_info.compress_debug
with config.compress_debug.
* lexsup.c (elf_static_list_options): Likewise.
* ldmain.c (main): Likewise. Apply bfd_applicable_file_flags
to compress debug flags added to output bfd.
When bfd_size_type is unsigned 64-bit integer and sizeof is unsigned
32-bit integer, subtraction in
*new_size += sizeof (Elf32_External_Chdr) - sizeof (Elf64_External_Chdr);
will overflow. Use
*new_size -= sizeof (Elf64_External_Chdr) - sizeof (Elf32_External_Chdr);
to avoid overflow.
PR binutils/29860
* compress.c (bfd_convert_section_setup): Avoid signed overflow
for new_size adjustment.
When running test-case gdb.base/longjmp.exp, we have:
...
PASS: gdb.base/longjmp.exp: next over setjmp (1)
...
PASS: gdb.base/longjmp.exp: next over setjmp (2)
...
The trailing " (1)" and " (2)" are interpreted as comments rather than parts
of the test name, and therefore this is a duplicate, which is currently not
detected by our duplicate detection mechanism (PR testsuite/29772).
Fix the duplicate by using with_test_prefix.
Tested on x86_64-linux.
When running test-case gdb.base/longjmp.exp on x86_64-linux, the master
longjmp breakpoint is set using probes and the test-case passes:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
0x00000000004005cc 49 if (setjmp (env) == 0) /* patt1 */^M
(gdb) PASS: gdb.base/longjmp.exp: next over longjmp(1)
next^M
56 resumes++;^M
(gdb) PASS: gdb.base/longjmp.exp: next into else block (1)
...
However, if I disable
create_longjmp_master_breakpoint_probe, we have instead:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
56 resumes++;^M
(gdb) FAIL: gdb.base/longjmp.exp: next over longjmp(1)
...
At first glance, the failure mode doesn't look too bad: we stop
a few insns later than the passing scenario.
For contrast, if we do the same on powerpc64le, the failure mode is:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
^M
Breakpoint 3, main () at longjmp.c:59^M
59 i = 1; /* miss_step_1 */^M
(gdb) FAIL: gdb.base/longjmp.exp: next over longjmp(1)
...
Here we only stop because of running into the safety net breakpoint at
miss_step_1.
So, how does this happen on x86_64? Let's look at the code:
...
4005c7: e8 94 fe ff ff call 400460 <_setjmp@plt>
4005cc: 85 c0 test %eax,%eax
4005ce: 75 1e jne 4005ee <main+0x3b>
4005d0: 8b 05 8e 0a 20 00 mov 0x200a8e(%rip),%eax # 601064 <longjmps>
4005d6: 83 c0 01 add $0x1,%eax
4005d9: 89 05 85 0a 20 00 mov %eax,0x200a85(%rip) # 601064 <longjmps>
4005df: be 01 00 00 00 mov $0x1,%esi
4005e4: bf 80 10 60 00 mov $0x601080,%edi
4005e9: e8 82 fe ff ff call 400470 <longjmp@plt>
4005ee: 8b 05 74 0a 20 00 mov 0x200a74(%rip),%eax # 601068 <resumes>
...
The next over the longjmp call at 4005e9 is supposed to stop at the longjmp
target at 4005cc, but instead we stop at 4005ee, where we have the step-resume
breakpoint inserted by the next. In other words, we accidentally "return"
from the longjmp call to the insn immediately after it (even though
a longjmp is a noreturn function).
Try to avoid this accident and make the failure mode on x86_64 the same as on
powerpc64le, by switching the then and else branch.
Tested on x86_64-linux.
According to the riscv psabi, the mapping relationship between the
DWARF registers and the machine registers is as follows:
DWARF Number | Register Name | Description
0 - 31 | x0 - x31 | Integer Registers
32 - 63 | f0 - f31 | Floating-point Registers
This is not modelled quite right in riscv_dwarf_reg_to_regnum, the
DWARF register numbers 31 and 63 are not handled correctly due to a
use of '<' instead of '<='. This commit fixes this issue.
For all the xh_mode usage in table, they are all using %XH, which will
print "{bad}" while EVEX.W=1. This makes this vex.w check unnecessary.
opcodes/ChangeLog:
* i386-dis.c (OP_E_memory): Remove vex.w check for xh_mode.
This flag also isn't needed, except for some sanity checks which we
can omit.
* elf.c (elf_fake_sections): Don't set SEC_ELF_COMPRESS for
compressed debug sections, just leave sh_name as -1.
(assign_file_positions_for_non_load_sections),
(assign_file_positions_except_relocs): Decide whether a section
needs compressing and thus should not have its file offset set
by looking at sh_name.
(_bfd_elf_assign_file_positions_for_non_load): Similarly decide
which sections need compressing.
* elflink.c (bfd_elf_final_link): Don't test SEC_ELF_COMPRESS.
* merge.c (_bfd_write_merged_section): Likewise.
* section.c (SEC_ELF_COMPRESS): Don't define.
(SEC_ELF_PURECODE): Renumber.
* bfd-in2.h: Regenerate.
SEC_ELF_RENAME is a flag used to effect section name changes when
compressing/decompressing zlib-gnu debug sections. This can be
accomplished more directly in one of the objcopy specific bfd
functions. Renaming for ld input is simplified too. Ld input object
files always have BFD_DECOMPRESS set.
bfd/
* compress.c (bfd_convert_section_size): Rename to..
(bfd_convert_section_setup): ..this. Handle objcopy renaming
of compressed/decompressed debug sections.
* elf.c (_bfd_elf_make_section_from_shdr): Only rename zdebug
input for linker.
(elf_fake_sections): Don't handle renaming of debug sections for
objcopy here.
* section.c (SEC_ELF_RENAME): Delete.
* bfd-in2.h: Regenerate.
binutils/
* objcopy.c (setup_section): Call bfd_convert_section_setup.
Don't call bfd_convert_section_size.
Define an enum instead of using ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD
in bfd and binutils, and move some functions from bfd.c to compress.c.
When looking at the COFF/PE debug compression support, I wondered
about extending it to support zstd. I likely won't do that, but
the compression header ch_type field isn't just ELF specific if these
headers are to be used in COFF/PE too.
bfd/
* bfd.c (bfd_update_compression_header),
(bfd_check_compression_header, bfd_get_compression_header_size),
(bfd_convert_section_size, bfd_convert_section_contents): Move to..
* compress.c: ..here.
(enum compression_type): New. Use it throughout file.
* elf.c (_bfd_elf_make_section_from_shdr): Replace uses of
ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD with ch_compress_zlib and
ch_compress_zstd.
* bfd-in2.h: Regenerate.
binutils/
* readelf.c (process_section_headers, dump_section_as_strings),
(dump_section_as_bytes, load_specific_debug_section): Replace
uses of ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD with
ch_compress_zlib and ch_compress_zstd.
Not a big deal, but it seems strange to check errno instead of the
ptrace return value to know whether it succeeded.
Change-Id: If0a6d0280ab0e5ecb077e546af0d6fe489c5b9fd
No caller cares about the value of *SIGINFO on failure. It's also
documented in the function doc that *SIGINFO is uninitialized (I
understand "untouched") on failure.
Change-Id: I5ef38a5f58e3635e109b919ddf6f827f38f1225a
I noticed that when running these two tests in sequence:
Running /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.ada/arrayptr.exp ...
ERROR: GDB process no longer exists
ERROR: Couldn't run foo-all
Running /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.ada/assign_1.exp ...
The results in gdb.sum are:
Running /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.ada/arrayptr.exp ...
PASS: gdb.ada/arrayptr.exp: scenario=all: compilation foo.adb
ERROR: GDB process no longer exists
UNRESOLVED: gdb.ada/arrayptr.exp: scenario=all: gdb_breakpoint: set breakpoint at foo.adb:40 (eof)
ERROR: Couldn't run foo-all
Running /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.ada/assign_1.exp ...
UNRESOLVED: gdb.ada/assign_1.exp: changing the language to ada
PASS: gdb.ada/assign_1.exp: set convenience variable $xxx to 1
The UNRESOLVED for arrayptr.exp is fine, as GDB crashes in that test,
while trying to run to main. However, the UNRESOLVED in assign_1.exp
doesn't make sense, GDB behaves as expected in that test:
(gdb) set lang ada^M
(gdb) UNRESOLVED: gdb.ada/assign_1.exp: changing the language to ada
print $xxx := 1^M
$1 = 1^M
(gdb) PASS: gdb.ada/assign_1.exp: set convenience variable $xxx to 1
The problem is that arrayptr.exp calls perror when failing to run to
main, then returns. perror makes it so that the next test (as in
pass/fail) will be recorded as UNRESOLVED. However, here, the next test
(as in pass/fail) is in the next test (as in .exp). Hence the spurious
UNRESOLVED in assign_1.exp.
These perror when failing to run to X are not really useful, especially
since runto records a FAIL on error, by default. Remove all the
perrors on runto failure I could find.
When there wasn't one already, add a return statement when failing to
run, to avoid running the test of the test unnecessarily.
I thought of adding a check ran between test (in gdb_finish
probably) where we would emit a warning if errcnt > 0, meaning a test
quit and left a perror "active". However, reading that variable would
poke into the DejaGNU internals, not sure it's a good idea.
Change-Id: I2203df6d06e199540b36f56470d1c5f1dc988f7b
