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2024-04-25gdb: remove gdbcmd.hSimon Marchi1-1/+1
Most files including gdbcmd.h currently rely on it to access things actually declared in cli/cli-cmds.h (setlist, showlist, etc). To make things easy, replace all includes of gdbcmd.h with includes of cli/cli-cmds.h. This might lead to some unused includes of cli/cli-cmds.h, but it's harmless, and much faster than going through the 170 or so files by hand. Change-Id: I11f884d4d616c12c05f395c98bbc2892950fb00f Approved-By: Tom Tromey <tom@tromey.com>
2024-04-22gdb: move store/extract integer functions to extract-store-integer.{c,h}Simon Marchi1-0/+1
Move the declarations out of defs.h, and the implementations out of findvar.c. I opted for a new file, because this functionality of converting integers to bytes and vice-versa seems a bit to generic to live in findvar.c. Change-Id: I524858fca33901ee2150c582bac16042148d2251 Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-03-26gdb, gdbserver, gdbsupport: remove includes of early headersSimon Marchi1-1/+0
Now that defs.h, server.h and common-defs.h are included via the `-include` option, it is no longer necessary for source files to include them. Remove all the inclusions of these files I could find. Update the generation scripts where relevant. Change-Id: Ia026cff269c1b7ae7386dd3619bc9bb6a5332837 Approved-By: Pedro Alves <pedro@palves.net>
2024-03-22Use std::string for disassembler optionsTom Tromey1-2/+2
I noticed that the disassembler_options code uses manual memory management. It seemed simpler to replace this with std::string. Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-03-22Constify get_disassembler_optionsTom Tromey1-1/+1
This changes get_disassembler_options to return a const char *. Approved-By: John Baldwin <jhb@FreeBSD.org>
2024-02-20gdb: pass frames as `const frame_info_ptr &`Simon Marchi1-37/+37
We currently pass frames to function by value, as `frame_info_ptr`. This is somewhat expensive: - the size of `frame_info_ptr` is 64 bytes, which is a bit big to pass by value - the constructors and destructor link/unlink the object in the global `frame_info_ptr::frame_list` list. This is an `intrusive_list`, so it's not so bad: it's just assigning a few points, there's no memory allocation as if it was `std::list`, but still it's useless to do that over and over. As suggested by Tom Tromey, change many function signatures to accept `const frame_info_ptr &` instead of `frame_info_ptr`. Some functions reassign their `frame_info_ptr` parameter, like: void the_func (frame_info_ptr frame) { for (; frame != nullptr; frame = get_prev_frame (frame)) { ... } } I wondered what to do about them, do I leave them as-is or change them (and need to introduce a separate local variable that can be re-assigned). I opted for the later for consistency. It might not be clear why some functions take `const frame_info_ptr &` while others take `frame_info_ptr`. Also, if a function took a `frame_info_ptr` because it did re-assign its parameter, I doubt that we would think to change it to `const frame_info_ptr &` should the implementation change such that it doesn't need to take `frame_info_ptr` anymore. It seems better to have a simple rule and apply it everywhere. Change-Id: I59d10addef687d157f82ccf4d54f5dde9a963fd0 Approved-By: Andrew Burgess <aburgess@redhat.com>
2024-02-13[gdb/tdep] Fix reverse execution of LDR(immediate) T4Tom de Vries1-0/+8
When running test-case gdb.reverse/func-map-to-same-line.exp on arm-linux with target board unix/-mthumb, we run into: ... (gdb) reverse-step func2 () at func-map-to-same-line.c:26 26 { (gdb) FAIL: gdb.reverse/func-map-to-same-line.exp: \ column_info_flag=column-info: step-test: reverse-step into func2 ... The FAIL is caused by incorrect recording of this insn: ... 4f6: f85d 7b04 ldr.w r7, [sp], #4 ... The insn updates the sp, but we don't record this: ... $ gdb -q -batch func-map-to-same-line \ -ex "b *func2+8" \ -ex run \ -ex record \ -ex "set debug record 2" \ -ex stepi Breakpoint 1 at 0x4f6: file func-map-to-same-line.c, line 27. Breakpoint 1, 0xaaaaa4f6 in func2 () at func-map-to-same-line.c:27 27 } /* END FUNC2 */ Process record: arm_process_record addr = 0xaaaaa4f6 Process record: add register num = 15 to record list. Process record: record_full_arch_list_add 0xabc6c460. Process record: add register num = 7 to record list. Process record: record_full_arch_list_add 0xabc3b868. Process record: add register num = 25 to record list. ... [ Note that sp is r13, and we see here only r15 (pc), r7, and r25 (ps). ] The problem is that the specific insn, an LDR(immediate) T4, is not handled in thumb2_record_ld_word. Fix this by detecting the insn in thumb2_record_ld_word, and recording the updated base register. Tested on arm-linux. Reported-By: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Approved-By: Luis Machado <luis.machado@arm.com> PR tdep/31278 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31278
2024-02-05[gdb/tdep] Fix use-after-free in arm_exidx_fill_cacheTom de Vries1-1/+1
On arm-linux the linaro CI occasionally reports: ... (gdb) up 10 #4 0x0001b864 in pthread_join () (gdb) FAIL: gdb.threads/staticthreads.exp: up 10 ... while this is expected: ... (gdb) up 10 #3 0x00010568 in main (argc=1, argv=0xfffeede4) at staticthreads.c:76 76 pthread_join (thread, NULL); (gdb) PASS: gdb.threads/staticthreads.exp: up 10 ... Thiago investigated the problem, and using valgrind found an invalid read in arm_exidx_fill_cache. The problem happens as follows: - an objfile and corresponding per_bfd are allocated - some memory is allocated in arm_exidx_new_objfile using objfile->objfile_obstack, for the "exception table entry cache". - a symbol reread is triggered, and the objfile, including the objfile_obstack, is destroyed - a new objfile is allocated, using the same per_bfd - again arm_exidx_new_objfile is called, but since the same per_bfd is used, it doesn't allocate any new memory for the "exception table entry cache". - the "exception table entry cache" is accessed by arm_exidx_fill_cache, and we have a use-after-free. This is a regression since commit a2726d4ff80 ("[ARM] Store exception handling information per-bfd instead of per-objfile"), which changed the "exception table entry cache" from per-objfile to per-bfd, but failed to update the obstack_alloc. Fix this by using objfile->per_bfd->storage_obstack instead of objfile->objfile_obstack. I couldn't reproduce the FAIL myself, but Thiago confirmed that the patch fixes it. Tested on arm-linux. Approved-By: Luis Machado <luis.machado@arm.com> PR tdep/31254 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31254
2024-01-24gdb/arm: Fix epilogue frame idThiago Jung Bauermann1-1/+1
arm_epilogue_frame_this_id has a comment saying that it fall backs to using the current PC if the function start address can't be identified, but it actually uses only the PC to make the frame id. This patch makes the code match the comment. Another hint that it's what is intended is that arm_prologue_this_id, a function almost identical to it, does that. The problem was found by code inspection. It fixes the following testsuite failures: FAIL: gdb.base/unwind-on-each-insn.exp: foo: instruction 9: check frame-id matches FAIL: gdb.reverse/solib-reverse.exp: reverse-next third shr1 FAIL: gdb.reverse/solib-reverse.exp: reverse-next second shr1 FAIL: gdb.reverse/solib-reverse.exp: reverse-next first shr1 FAIL: gdb.reverse/solib-reverse.exp: reverse-next generic FAIL: gdb.reverse/solib-reverse.exp: reverse-step into solib function one FAIL: gdb.reverse/solib-reverse.exp: reverse-step within solib function one FAIL: gdb.reverse/solib-reverse.exp: reverse-step into solib function two FAIL: gdb.reverse/solib-reverse.exp: reverse-step within solib function two Tested on arm-linux-gnueabi-hf.
2024-01-12Update copyright year range in header of all files managed by GDBAndrew Burgess1-1/+1
This commit is the result of the following actions: - Running gdb/copyright.py to update all of the copyright headers to include 2024, - Manually updating a few files the copyright.py script told me to update, these files had copyright headers embedded within the file, - Regenerating gdbsupport/Makefile.in to refresh it's copyright date, - Using grep to find other files that still mentioned 2023. If these files were updated last year from 2022 to 2023 then I've updated them this year to 2024. I'm sure I've probably missed some dates. Feel free to fix them up as you spot them.
2023-12-14gdb: migrate arm to new gdbarch_pseudo_register_writeSimon Marchi1-26/+36
Make arm use the new gdbarch_pseudo_register_write. This fixes writing pseudo registers to non-current frames for that architecture. Change-Id: Icb2a649ab6394817844230e9e94c3d0564d2f765 Reviewed-By: John Baldwin <jhb@FreeBSD.org> Approved-by: Luis Machado <luis.machado@arm.com>
2023-12-14gdb: migrate arm to gdbarch_pseudo_register_read_valueSimon Marchi1-32/+44
Make arm use the "newer" gdbarch_pseudo_register_read_value. This fixes reading pseudo registers in non-current frames on that architecture. Change-Id: Ic4d3d5d96957a4addfa3443c7b567dc4a31794a9 Reviewed-By: John Baldwin <jhb@FreeBSD.org> Approved-by: Luis Machado <luis.machado@arm.com>
2023-12-14gdb: rename gdbarch_pseudo_register_write to ↵Simon Marchi1-1/+1
gdbarch_deprecated_pseudo_register_write The next patch introduces a new variant of gdbarch_pseudo_register_write that takes a frame instead of a regcache for implementations to write raw registers. Rename to old one to make it clear it's deprecated. Change-Id: If8872c89c6f8a1edfcab983eb064248fd5ff3115 Reviewed-By: John Baldwin <jhb@FreeBSD.org>
2023-12-14gdb: change value_of_register and value_of_register_lazy to take the next frameSimon Marchi1-2/+2
Some functions related to the handling of registers in frames accept "this frame", for which we want to read or write the register values, while other functions accept "the next frame", which is the frame next to that. The later is needed because we sometimes need to read register values for a frame that does not exist yet (usually when trying to unwind that frame-to-be). value_of_register and value_of_register_lazy both take "this frame", even if what they ultimately want internally is "the next frame". This is annoying if you are in a spot that currently has "the next frame" and need to call one of these functions (which happens later in this series). You need to get the previous frame only for those functions to get the next frame again. This is more manipulations, more chances of mistake. I propose to change these functions (and a few more functions in the subsequent patches) to operate on "the next frame". Things become a bit less awkward when all these functions agree on which frame they take. So, in this patch, change value_of_register_lazy and value_of_register to take "the next frame" instead of "this frame". This adds a lot of get_next_frame_sentinel_okay, but if we convert the user registers API to also use "the next frame" instead of "this frame", it will get simple again. Change-Id: Iaa24815e648fbe5ae3c214c738758890a91819cd Reviewed-By: John Baldwin <jhb@FreeBSD.org>
2023-12-14gdb: use reg_buffer_common throughout gdbsupport/common-regcache.hSimon Marchi1-2/+3
Right now, gdbsupport/common-regcache.h contains two abstractons for a regcache. An opaque type `regcache` (gdb and gdbserver both have their own regcache that is the concrete version of this) and an abstract base class `reg_buffer_common`, that is the base of regcaches on both sides. These abstractions allow code to be written for both gdb and gdbserver, for instance in the gdb/arch sub-directory. However, having two different abstractions is impractical. If some common code has a regcache, and wants to use an operation defined on reg_buffer_common, it can't. It would be better to have just one. Change all instances of `regcache *` in gdbsupport/common-regcache.h to be `reg_buffer_common *`, then fix fallouts. Implementations in gdb and gdbserver now need to down-cast (using gdb::checked_static_cast) from reg_buffer_common to their concrete regcache type. Some of them could be avoided by changing free functions (like regcache_register_size) to be virtual methods on reg_buffer_common. I tried it, it seems to work, but I did not include it in this series to avoid adding unnecessary changes. Change-Id: Ia5503adb6b5509a0f4604bd2a68b4642cc5283fd Reviewed-by: John Baldwin <jhb@FreeBSD.org>
2023-11-29Use C++17 [[fallthrough]] attributeTom Tromey1-1/+1
This changes gdb to use the C++17 [[fallthrough]] attribute rather than special comments. This was mostly done by script, but I neglected a few spellings and so also fixed it up by hand. I suspect this fixes the bug mentioned below, by switching to a standard approach that, presumably, clang supports. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23159 Approved-By: John Baldwin <jhb@FreeBSD.org> Approved-By: Luis Machado <luis.machado@arm.com> Approved-By: Pedro Alves <pedro@palves.net>
2023-11-21gdb: Replace gdb::optional with std::optionalLancelot Six1-2/+2
Since GDB now requires C++17, we don't need the internally maintained gdb::optional implementation. This patch does the following replacing: - gdb::optional -> std::optional - gdb::in_place -> std::in_place - #include "gdbsupport/gdb_optional.h" -> #include <optional> This change has mostly been done automatically. One exception is gdbsupport/thread-pool.* which did not use the gdb:: prefix as it already lives in the gdb namespace. Change-Id: I19a92fa03e89637bab136c72e34fd351524f65e9 Approved-By: Tom Tromey <tom@tromey.com> Approved-By: Pedro Alves <pedro@palves.net>
2023-11-07gdb/arm: remove thumb bit in arm_adjust_breakpoint_addressSimon Marchi1-3/+6
When compiling gdb with -fsanitize=address on ARM, I get a crash in test gdb.arch/arm-disp-step.exp, reproduced easily with: $ ./gdb -nx -q --data-directory=data-directory testsuite/outputs/gdb.arch/arm-disp-step/arm-disp-step -ex "break *test_call_end" Reading symbols from testsuite/outputs/gdb.arch/arm-disp-step/arm-disp-step... ================================================================= ==23295==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb4a14fd1 at pc 0x01a48871 bp 0xbeab8490 sp 0xbeab8494 Since it doesn't require running the program, it can be reproduced locally on a dev machine other than ARM, after acquiring the test binary. The length of the allocate buffer `buf` is 1, and we try to extract an integer of size 2 from it. The length of 1 comes from the subtraction `bpaddr - boundary`. Normally, on ARM, all instructions are aligned on a multiple of 2, so it's weird for this subtraction to result in 1. In this case, boundary comes from the result of find_pc_partial_function returning 0x549: (gdb) p/x bpaddr $2 = 0x54a (gdb) p/x boundary $3 = 0x549 (gdb) p/x bpaddr - boundary $4 = 0x1 0x549 is the address of the test_call_subr label, 0x548, with the thumb bit enabled. Before doing some math with the address, I think we need to strip the thumb bit, like is done elsewhere (for instance for bpaddr earlier in the same function). I wonder if find_pc_partial_function should do that itself, in order to return an address that is suitable for arithmetic. In any case, that would be a change with a broad impact, so for now just fix the issue locally. After the patch: $ ./gdb -nx -q --data-directory=data-directory testsuite/outputs/gdb.arch/arm-disp-step/arm-disp-step -ex "break *test_call_end" Reading symbols from testsuite/outputs/gdb.arch/arm-disp-step/arm-disp-step... Breakpoint 1 at 0x54a: file /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.arch/arm-disp-step.S, line 103. Change-Id: I74fc458dbea0d2c1e1f5eadd90755188df089288 Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-30Fix fixed-point "return" on ARMTom Tromey1-3/+15
On a big-endian ARM machine, the "return" command resulted in the wrong value being returned when the function had a fixed-point return type. This patch fixes the problem by unpacking and repacking the fixed-point type appropriately. Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-30Fix range-type "return" command on ARMTom Tromey1-0/+3
On big-endian ARM, "return"ing from a function that returned a range type did not work. This patch strips the range type to treat the function as though it were returning the underlying type instead. Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-30Fix "finish" for vector types on ARMTom Tromey1-20/+6
On a big-endian ARM system, "finish" printed the wrong value when finishing from a function that returned a vector type. Similarly, calls to a function also resulted in the wrong value being passed. I think both the read- and write-functions here should ignore the endian-ness. I tested this using the AdaCore internal test suite; the test case that caught this is identical to gdb.base/gnu_vector.exp. Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-30Fix "finish" with range types on ARMTom Tromey1-0/+3
On ARM (I tested big-endian but it may not matter), "finish" can sometimes print the wrong result when the return type is a range type. Range types should really be treated as their underlying type (normally integer, but sometimes fixed-point). This patch implements this. Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-30Fix calls with small integers on ARMTom Tromey1-3/+0
On big-endian ARM, an inferior call with a small integer will pass the wrong value. This patch fixes the problem. Because the code here works using scalar values, and not just bytes, left-shifting is unnecessary. Approved-By: Luis Machado <luis.machado@arm.com>
2023-10-10gdb: remove target_gdbarchSimon Marchi1-7/+8
This function is just a wrapper around the current inferior's gdbarch. I find that having that wrapper just obscures where the arch is coming from, and that it's often used as "I don't know which arch to use so I'll use this magical target_gdbarch function that gets me an arch" when the arch should in fact come from something in the context (a thread, objfile, symbol, etc). I think that removing it and inlining `current_inferior ()->arch ()` everywhere will make it a bit clearer where that arch comes from and will trigger people into reflecting whether this is the right place to get the arch or not. Change-Id: I79f14b4e4934c88f91ca3a3155f5fc3ea2fadf6b Reviewed-By: John Baldwin <jhb@FreeBSD.org> Approved-By: Andrew Burgess <aburgess@redhat.com>
2023-10-05gdb: add all_objfiles_removed observerSimon Marchi1-1/+1
The new_objfile observer is currently used to indicate both when a new objfile is added to program space (when passed non-nullptr) and when all objfiles of a program space were just removed (when passed nullptr). I think this is confusing (and Andrew apparently thinks so too [1]). Add a new "all_objfiles_removed" observer to remove the second role from "new_objfile". Some existing users of new_objfile do nothing if the passed objfile is nullptr. For them, we can simply drop the nullptr check. For others, add a new all_objfiles_removed callback, and refactor things a bit to keep the existing behavior as much as possible. Some callbacks relied on current_program_space, and following the refactoring now use either objfile->pspace or the pspace passed to all_objfiles_removed. I think this should be relatively safe, and in general a step in the right direction. On the notify side, I found only one call site to change from new_objfile to all_objfiles_removed, in clear_symtab_users. It is not entirely clear to me that this is entirely correct. clear_symtab_users appears to be called in spots that don't remove all objfiles (functions finish_new_objfile, remove_symbol_file_command, reread_symbols, do_module_cleanups). But I think that this patch at least makes the current code clearer. [1] https://gitlab.com/gnutools/binutils-gdb/-/commit/a0a031bce0527b1521788b5dad640e7883b3a252 Change-Id: Icb648f72862e056267f30f44dd439bd4ec766f13 Approved-By: Tom Tromey <tom@tromey.com>
2023-09-20Remove explanatory comments from includesTom Tromey1-2/+2
I noticed a comment by an include and remembered that I think these don't really provide much value -- sometimes they are just editorial, and sometimes they are obsolete. I think it's better to just remove them. Tested by rebuilding. Approved-By: Andrew Burgess <aburgess@redhat.com>
2023-08-31gdb: remove TYPE_FIELD_BITSIZESimon Marchi1-1/+1
Replace with type::field + field::bitsize. Change-Id: I2a24755a33683e4a2775a6d2a7b7a9ae7362e43a Approved-By: Tom Tromey <tom@tromey.com>
2023-06-09[AArch64,arm] Fix some formatting issues in the aarch64/arm codebaseLuis Machado1-11/+11
As noted by Tom Tromey, there are some formatting issues with the ternary operator in the aarch64/arm codebase. This patch fixes those. Reviewed-By: Tom Tromey <tom@tromey.com>
2023-06-07Fix PR30369 regression on aarch64/arm (PR30506)Tom de Vries1-3/+18
The gdb.dwarf2/dw2-prologue-end-2.exp test was failing for both AArch64 and Arm. As Tom pointed out here (https://inbox.sourceware.org/gdb-patches/6663707c-4297-c2f2-a0bd-f3e84fc62aad@suse.de/), there are issues with both the prologue skipper for AArch64 and Arm and an incorrect assumption by the testcase. This patch fixes both of AArch64's and Arm's prologue skippers to not skip past the end of a function. It also incorporates a fix to the testcase so it doesn't assume the prologue skipper will stop at the first instruction of the functions/labels. Regression-tested on aarch64-linux/arm-linux Ubuntu 20.04/22.04 and x86_64-linux Ubuntu 20.04. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30506 Co-Authored-By: Tom de Vries <tdevries@suse.de> Co-Authored-By: Luis Machado <luis.machado@arm.com>
2023-06-05[gdb] Fix more typosTom de Vries1-1/+1
Fix some more typos: - distinquish -> distinguish - actualy -> actually - singe -> single - frash -> frame - chid -> child - dissassembler -> disassembler - uninitalized -> uninitialized - precontidion -> precondition - regsiters -> registers - marge -> merge - sate -> state - garanteed -> guaranteed - explictly -> explicitly - prefices (nonstandard plural) -> prefixes - bondary -> boundary - formated -> formatted - ithe -> the - arrav -> array - coresponding -> corresponding - owend -> owned - fials -> fails - diasm -> disasm - ture -> true - tpye -> type There's one code change, the name of macro SIG_CODE_BONDARY_FAULT changed to SIG_CODE_BOUNDARY_FAULT. Tested on x86_64-linux.
2023-05-07Remove ALL_OBJFILE_OSECTIONSTom Tromey1-3/+1
This replaces ALL_OBJFILE_OSECTIONS with an iterator so that for-each can be used.
2023-05-01Replace field_is_static with a methodTom Tromey1-1/+1
This changes field_is_static to be a method on struct field, and updates all the callers. Most of this patch was written by script. Regression tested on x86-64 Fedora 36.
2023-04-06gdb: fix reg corruption from displaced stepping on amd64Andrew Burgess1-1/+25
This commit aims to address a problem that exists with the current approach to displaced stepping, and was identified in PR gdb/22921. Displaced stepping is currently supported on AArch64, ARM, amd64, i386, rs6000 (ppc), and s390. Of these, I believe there is a problem with the current approach which will impact amd64 and ARM, and can lead to random register corruption when the inferior makes use of asynchronous signals and GDB is using displaced stepping. The problem can be found in displaced_step_buffers::finish in displaced-stepping.c, and is this; after GDB tries to perform a displaced step, and the inferior stops, GDB classifies the stop into one of two states, either the displaced step succeeded, or the displaced step failed. If the displaced step succeeded then gdbarch_displaced_step_fixup is called, which has the job of fixing up the state of the current inferior as if the step had not been performed in a displaced manner. This all seems just fine. However, if the displaced step is considered to have not completed then GDB doesn't call gdbarch_displaced_step_fixup, instead GDB remains in displaced_step_buffers::finish and just performs a minimal fixup which involves adjusting the program counter back to its original value. The problem here is that for amd64 and ARM setting up for a displaced step can involve changing the values in some temporary registers. If the displaced step succeeds then this is fine; after the step the temporary registers are restored to their original values in the architecture specific code. But if the displaced step does not succeed then the temporary registers are never restored, and they retain their modified values. In this context a temporary register is simply any register that is not otherwise used by the instruction being stepped that the architecture specific code considers safe to borrow for the lifetime of the instruction being stepped. In the bug PR gdb/22921, the amd64 instruction being stepped is an rip-relative instruction like this: jmp *0x2fe2(%rip) When we displaced step this instruction we borrow a register, and modify the instruction to something like: jmp *0x2fe2(%rcx) with %rcx having its value adjusted to contain the original %rip value. Now if the displaced step does not succeed, then %rcx will be left with a corrupted value. Obviously corrupting any register is bad; in the bug report this problem was spotted because %rcx is used as a function argument register. And finally, why might a displaced step not succeed? Asynchronous signals provides one reason. GDB sets up for the displaced step and, at that precise moment, the OS delivers a signal (SIGALRM in the bug report), the signal stops the inferior at the address of the displaced instruction. GDB cancels the displaced instruction, handles the signal, and then tries again with the displaced step. But it is that first cancellation of the displaced step that causes the problem; in that case GDB (correctly) sees the displaced step as having not completed, and so does not perform the architecture specific fixup, leaving the register corrupted. The reason why I think AArch64, rs600, i386, and s390 are not effected by this problem is that I don't believe these architectures make use of any temporary registers, so when a displaced step is not completed successfully, the minimal fix up is sufficient. On amd64 we use at most one temporary register. On ARM, looking at arm_displaced_step_copy_insn_closure, we could modify up to 16 temporary registers, and the instruction being displaced stepped could be expanded to multiple replacement instructions, which increases the chances of this bug triggering. This commit only aims to address the issue on amd64 for now, though I believe that the approach I'm proposing here might be applicable for ARM too. What I propose is that we always call gdbarch_displaced_step_fixup. We will now pass an extra argument to gdbarch_displaced_step_fixup, this a boolean that indicates whether GDB thinks the displaced step completed successfully or not. When this flag is false this indicates that the displaced step halted for some "other" reason. On ARM GDB can potentially read the inferior's program counter in order figure out how far through the sequence of replacement instructions we got, and from that GDB can figure out what fixup needs to be performed. On targets like amd64 the problem is slightly easier as displaced stepping only uses a single replacement instruction. If the displaced step didn't complete the GDB knows that the single instruction didn't execute. The point is that by always calling gdbarch_displaced_step_fixup, each architecture can now ensure that the inferior state is fixed up correctly in all cases, not just the success case. On amd64 this ensures that we always restore the temporary register value, and so bug PR gdb/22921 is resolved. In order to move all architectures to this new API, I have moved the minimal roll-back version of the code inside the architecture specific fixup functions for AArch64, rs600, s390, and ARM. For all of these except ARM I think this is good enough, as no temporaries are used all that's needed is the program counter restore anyway. For ARM the minimal code is no worse than what we had before, though I do consider this architecture's displaced-stepping broken. I've updated the gdb.arch/amd64-disp-step.exp test to cover the 'jmpq*' instruction that was causing problems in the original bug, and also added support for testing the displaced step in the presence of asynchronous signal delivery. I've also added two new tests (for amd64 and i386) that check that GDB can correctly handle displaced stepping over a single instruction that branches to itself. I added these tests after a first version of this patch relied too much on checking the program-counter value in order to see if the displaced instruction had executed. This works fine in almost all cases, but when an instruction branches to itself a pure program counter check is not sufficient. The new tests expose this problem. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=22921 Approved-By: Pedro Alves <pedro@palves.net>
2023-04-01gdb/arm: Fix backtrace for pthread_cond_timedwaitJan Kratochvil1-17/+25
GDB expected PC should point right after the SVC instruction when the syscall is active. But some active syscalls keep PC pointing to the SVC instruction itself. This leads to a broken backtrace like: Backtrace stopped: previous frame identical to this frame (corrupt stack?) #0 0xb6f8681c in pthread_cond_timedwait@@GLIBC_2.4 () from /lib/arm-linux-gnueabihf/libpthread.so.0 #1 0xb6e21f80 in ?? () The reason is that .ARM.exidx unwinder gives up if PC does not point right after the SVC (syscall) instruction. I did not investigate why but some syscalls will point PC to the SVC instruction itself. This happens for the "futex" syscall used by pthread_cond_timedwait. That normally does not matter as ARM prologue unwinder gets called instead of the .ARM.exidx one. Unfortunately some glibc calls have more complicated prologue where the GDB unwinder fails to properly determine the return address (that is in fact an orthogonal GDB bug). I expect it is due to the "vpush" there in this case but I did not investigate it more: Dump of assembler code for function pthread_cond_timedwait@@GLIBC_2.4: 0xb6f8757c <+0>: push {r4, r5, r6, r7, r8, r9, r10, r11, lr} 0xb6f87580 <+4>: mov r10, r2 0xb6f87584 <+8>: vpush {d8} Regression tested on armv7l kernel 5.15.32-v7l+ (Raspbian 11). Approved-By: Luis Machado <luis.machado@arm.com>
2023-03-18Unify arch_float_type and init_float_typeTom Tromey1-3/+6
This unifies arch_float_type and init_float_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-13gdb: add gdbarch::displaced_step_buffer_lengthAndrew Burgess1-1/+3
The gdbarch::max_insn_length field is used mostly to support displaced stepping; it controls the size of the buffers allocated for the displaced-step instruction, and is also used when first copying the instruction, and later, when fixing up the instruction, in order to read in and parse the instruction being stepped. However, it has started to be used in other places in GDB, for example, it's used in the Python disassembler API, and it is used on amd64 as part of branch-tracing instruction classification. The problem is that the value assigned to max_insn_length is not always the maximum instruction length, but sometimes is a multiple of that length, as required to support displaced stepping, see rs600, ARM, and AArch64 for examples of this. It seems to me that we are overloading the meaning of the max_insn_length field, and I think that could potentially lead to confusion. I propose that we add a new gdbarch field, gdbarch::displaced_step_buffer_length, this new field will do exactly what it says on the tin; represent the required displaced step buffer size. The max_insn_length field can then do exactly what it claims to do; represent the maximum length of a single instruction. As some architectures (e.g. i386, and amd64) only require their displaced step buffers to be a single instruction in size, I propose that the default for displaced_step_buffer_length will be the value of max_insn_length. Architectures than need more buffer space can then override this default as needed. I've updated all architectures to setup the new field if appropriate, and I've audited all calls to gdbarch_max_insn_length and switched to gdbarch_displaced_step_buffer_length where appropriate. There should be no user visible changes after this commit. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-09gdb, gdbserver, gdbsupport: fix whitespace issuesSimon Marchi1-1/+1
Replace spaces with tabs in a bunch of places. Change-Id: If0f87180f1d13028dc178e5a8af7882a067868b0
2023-02-27Remove old GNU indent directivesTom Tromey1-2/+0
Now that gdb_indent.sh has been removed, I think it makes sense to also remove the directives intended for GNU indent.
2023-02-13Turn remaining value_contents functions into methodsTom Tromey1-1/+1
This turns the remaining value_contents functions -- value_contents, value_contents_all, value_contents_for_printing, and value_contents_for_printing_const -- into methods of value. It also converts the static functions require_not_optimized_out and require_available to be private methods. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-02-13Turn some value_contents functions into methodsTom Tromey1-2/+2
This turns value_contents_raw, value_contents_writeable, and value_contents_all_raw into methods on value. The remaining functions will be changed later in the series; they were a bit trickier and so I didn't include them in this patch. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-02-13Turn allocate_value into a static "constructor"Tom Tromey1-2/+2
This changes allocate_value to be a static "constructor" of value. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-02-13Turn value_type into methodTom Tromey1-3/+3
This changes value_type to be a method of value. Much of this patch was written by script. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-01-25gdb/arm: Use new dwarf2 function cacheTorbjörn SVENSSON1-32/+65
This patch resolves the performance issue reported in pr/29738 by caching the values for the stack pointers for the inner frame. By doing so, the impact can be reduced to checking the state and returning the appropriate value. Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com> Signed-off-by: Yvan Roux <yvan.roux@foss.st.com>
2023-01-20gdb: remove language.h include from frame.hSimon Marchi1-0/+1
This helps resolve some cyclic include problem later in the series. The only language-related thing frame.h needs is enum language, and that is in defs.h. Doing so reveals that a bunch of files were relying on frame.h to include language.h, so fix the fallouts here and there. Change-Id: I178a7efec1953c2d088adb58483bade1f349b705 Reviewed-By: Bruno Larsen <blarsen@redhat.com>
2023-01-05gdb: make gdbarch_alloc take ownership of the tdepSimon Marchi1-3/+3
It's currently not clear how the ownership of gdbarch_tdep objects works. In fact, nothing ever takes ownership of it. This is mostly fine because we never free gdbarch objects, and thus we never free gdbarch_tdep objects. There is an exception to that however: when initialization fails, we do free the gdbarch object that is not going to be used, and we free the tdep too. Currently, i386 and s390 do it. To make things clearer, change gdbarch_alloc so that it takes ownership of the tdep. The tdep is thus automatically freed if the gdbarch is freed. Change all gdbarch initialization functions to pass a new gdbarch_tdep object to gdbarch_alloc and then retrieve a non-owning reference from the gdbarch object. Before this patch, the xtensa architecture had a single global instance of xtensa_gdbarch_tdep. Since we need to pass a dynamically allocated gdbarch_tdep_base instance to gdbarch_alloc, remove this global instance, and dynamically allocate one as needed, like we do for all other architectures. Make the `rmap` array externally visible and rename it to the less collision-prone `xtensa_rmap` name. Change-Id: Id3d70493ef80ce4bdff701c57636f4c79ed8aea2 Approved-By: Andrew Burgess <aburgess@redhat.com>
2023-01-03Fix inferior calls with variably-sized return typeTom Tromey1-11/+19
This patch updates the gdbarch_return_value_as_value implementations to work correctly with variably-sized return types.
2023-01-03Convert selected architectures to gdbarch_return_value_as_valueTom Tromey1-2/+9
This converts a few selected architectures to use gdbarch_return_value_as_value rather than gdbarch_return_value. The architectures are just the ones that I am able to test. This patch should not introduce any behavior changes.
2023-01-01Update copyright year range in header of all files managed by GDBJoel Brobecker1-1/+1
This commit is the result of running the gdb/copyright.py script, which automated the update of the copyright year range for all source files managed by the GDB project to be updated to include year 2023.
2022-12-20sim: move register headers into sim/ namespace [PR sim/29869]Mike Frysinger1-1/+1
These headers define the register numbers for each port to implement the sim_fetch_register & sim_store_register interfaces. While gdb uses these, the APIs are part of the sim, not gdb. Move the headers out of the gdb/ include namespace and into sim/ instead.
2022-11-23gdb/arm: Include FType bit in EXC_RETURN pattern on v8mTorbjörn SVENSSON1-6/+13
For v8m, the EXC_RETURN pattern, without security extension, consists of FType, Mode and SPSEL. These are the same bits that are used in v7m. This patch extends the list of patterns to include also the FType bit and not just Mode and SPSEL bits for v8m targets without security extension. Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>