This patch replaces some code in the record targets with target method
delegation.
record-full.c stores pointers to many target methods when the record
target is pushed. Then it later delegates some calls via these. This
is wrong because it violates the target stack contract. In particular
it is ok to unpush a target at any stratum, but record-full does not
keep track of this, so it could potentially call into an unpushed
target.
This patch fixes the problem by using the newly-introduced generic
approach to target delegation for the methods in question.
2014-02-19 Tom Tromey <tromey@redhat.com>
* record-full.c (record_full_beneath_to_resume_ops)
(record_full_beneath_to_resume, record_full_beneath_to_wait_ops)
(record_full_beneath_to_wait)
(record_full_beneath_to_store_registers_ops)
(record_full_beneath_to_store_registers)
(record_full_beneath_to_xfer_partial_ops)
(record_full_beneath_to_xfer_partial)
(record_full_beneath_to_insert_breakpoint_ops)
(record_full_beneath_to_insert_breakpoint)
(record_full_beneath_to_remove_breakpoint_ops)
(record_full_beneath_to_remove_breakpoint)
(record_full_beneath_to_stopped_by_watchpoint)
(record_full_beneath_to_stopped_data_address)
(record_full_beneath_to_async, tmp_to_resume_ops, tmp_to_resume)
(tmp_to_wait_ops, tmp_to_wait, tmp_to_store_registers_ops)
(tmp_to_store_registers, tmp_to_xfer_partial_ops)
(tmp_to_xfer_partial, tmp_to_instmp_to_insert_breakpoint_ops)
(tmp_to_insert_breakpoint, tmp_to_remove_breakpoint_ops)
(tmp_to_remove_breakpoint, tmp_to_stopped_by_watchpoint)
(tmp_to_stopped_data_address, tmp_to_async): Remove.
(record_full_open_1, record_full_open): Update. Use RECORD_IS_USED.
(record_full_resume, record_full_wait_1)
(record_full_stopped_by_watchpoint, record_full_stopped_data_address)
(record_full_store_registers, record_full_xfer_partial)
(record_full_insert_breakpoint, record_full_remove_breakpoint)
(record_full_async, record_full_core_xfer_partial): Use target
delegation.
* target-delegates.c: Rebuild.
* target.c (current_xfer_partial): Remove.
(update_current_target): Do not INHERIT or de_fault
to_insert_breakpoint, to_remove_breakpoint,
to_stopped_data_address, to_stopped_by_watchpoint, to_can_async_p,
to_is_async_p, to_async. Do not set to_xfer_partial field.
(default_xfer_partial): Simplify.
(current_xfer_partial): Remove.
(target_wait, target_resume): Simplify.
(find_default_can_async_p, find_default_is_async_p): Update.
(init_dummy_target): Don't set to_can_async_p, to_is_async_p,
to_xfer_partial, to_stopped_by_watchpoint,
to_stopped_data_address.
(target_store_registers): Simplify.
(forward_target_remove_breakpoint)
(forward_target_insert_breakpoint): Remove.
(target_remove_breakpoint, target_insert_breakpoint)
(debug_to_insert_breakpoint, debug_to_remove_breakpoint): Update.
* target.h (struct target_ops) <to_resume, to_wait,
to_store_registers, to_insert_breakpoint, to_remove_breakpoint,
to_stopped_by_watchpoint, to_stopped_data_address, to_can_async_p,
to_is_async_p, to_async, to_xfer_partial>: Add TARGET_DEFAULT
markup.
(forward_target_remove_breakpoint)
(forward_target_insert_breakpoint): Remove.
* record-btrace.c (record_btrace_remove_breakpoint): Delegate
directly.
(record_btrace_insert_breakpoint): Delegate directly.
This patch does the conversion of to_xfer_partial from
LONGEST (*to_xfer_partial) (struct target_ops *ops,
enum target_object object, const char *annex,
gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len);
to
enum target_xfer_status (*to_xfer_partial) (struct target_ops *ops,
enum target_object object, const char *annex,
gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len, ULONGEST *xfered_len);
It changes to_xfer_partial return the transfer status and the transfered
length by *XFERED_LEN. Generally, the return status has three stats,
- TARGET_XFER_OK,
- TARGET_XFER_EOF,
- TARGET_XFER_E_XXXX,
See the comments to them in 'enum target_xfer_status'. Note that
Pedro suggested not name TARGET_XFER_DONE, as it is confusing,
compared with "TARGET_XFER_OK". We finally name it TARGET_XFER_EOF.
With this change, GDB core can handle unavailable data in a convenient
way.
The rationale behind this change was mentioned here
https://sourceware.org/ml/gdb-patches/2013-10/msg00761.html
Consider an object/value like this:
0 100 150 200 512
DDDDDDDDDDDxxxxxxxxxDDDDDD...DDIIIIIIIIIIII..III
where D is valid data, and xxx is unavailable data, and I is beyond
the end of the object (Invalid). Currently, if we start the
xfer at 0, requesting, say 512 bytes, we'll first get back 100 bytes.
The xfer machinery then retries fetching [100,512), and gets back
TARGET_XFER_E_UNAVAILABLE. That's sufficient when you're either
interested in either having the whole of the 512 bytes available,
or erroring out. But, in this scenario, we're interested in
the data at [150,512). The problem is that the last
TARGET_XFER_E_UNAVAILABLE gives us no indication where to
start the read next. We'd need something like:
get me [0,512) >>>
<<< here's [0,100), *xfered_len is 100, returns TARGET_XFER_OK
get me [100,512) >>> (**1)
<<< [100,150) is unavailable, *xfered_len is 50, return TARGET_XFER_E_UNAVAILABLE.
get me [150,512) >>>
<<< here's [150,200), *xfered_len is 50, return TARGET_XFER_OK.
get me [200,512) >>>
<<< no more data, return TARGET_XFER_EOF.
This naturally implies pushing down the decision of whether
to return TARGET_XFER_E_UNAVAILABLE or something else
down to the target. (Which kinds of leads back to tfile
itself reading from RO memory from file (though we could
export a function in exec.c for that that tfile delegates to,
instead of re-adding the old code).
Beside this change, we also add a macro TARGET_XFER_STATUS_ERROR_P to
check whether a status is an error or not, to stop using "status < 0".
This patch also eliminates the comparison between status and 0.
No target implementations to to_xfer_partial adapts this new
interface. The interface still behaves as before.
gdb:
2014-02-11 Yao Qi <yao@codesourcery.com>
* target.h (enum target_xfer_error): Rename to ...
(enum target_xfer_status): ... it. New. All users updated.
(enum target_xfer_status) <TARGET_XFER_OK>, <TARGET_XFER_EOF>:
New.
(TARGET_XFER_STATUS_ERROR_P): New macro.
(target_xfer_error_to_string): Remove declaration.
(target_xfer_status_to_string): Declare.
(target_xfer_partial_ftype): Adjust it.
(struct target_ops) <to_xfer_partial>: Return
target_xfer_status. Add argument xfered_len. Update
comments.
* target.c (target_xfer_error_to_string): Rename to ...
(target_xfer_status_to_string): ... it. New. All callers
updated.
(target_read_live_memory): Likewise. Call target_xfer_partial
instead of target_read.
(memory_xfer_live_readonly_partial): Return
target_xfer_status. Add argument xfered_len.
(raw_memory_xfer_partial): Likewise.
(memory_xfer_partial_1): Likewise.
(memory_xfer_partial): Likewise.
(target_xfer_partial): Likewise. Check *XFERED_LEN is set
properly. Update debug message.
(default_xfer_partial, current_xfer_partial): Likewise.
(target_write_partial): Likewise.
(target_read_partial): Likewise. All callers updated.
(read_whatever_is_readable): Likewise.
(target_write_with_progress): Likewise.
(target_read_alloc_1): Likewise.
* aix-thread.c (aix_thread_xfer_partial): Likewise.
* auxv.c (procfs_xfer_auxv): Likewise.
(ld_so_xfer_auxv, memory_xfer_auxv): Likewise.
* bfd-target.c (target_bfd_xfer_partial): Likewise.
* bsd-kvm.c (bsd_kvm_xfer_partial): Likewise.
* bsd-uthread.c (bsd_uthread_xfer_partia): Likewise.
* corefile.c (read_memory): Adjust.
* corelow.c (core_xfer_partial): Likewise.
* ctf.c (ctf_xfer_partial): Likewise.
* darwin-nat.c (darwin_read_dyld_info): Likewise. All callers
updated.
(darwin_xfer_partial): Likewise.
* exec.c (section_table_xfer_memory_partial): Likewise. All
callers updated.
(exec_xfer_partial): Likewise.
* exec.h (section_table_xfer_memory_partial): Update
declaration.
* gnu-nat.c (gnu_xfer_memory): Likewise. Assert 'res' is not
negative.
(gnu_xfer_partial): Likewise.
* ia64-hpux-nat.c (ia64_hpux_xfer_memory_no_bs): Likewise.
(ia64_hpux_xfer_memory, ia64_hpux_xfer_uregs): Likewise.
(ia64_hpux_xfer_solib_got): Likewise.
* inf-ptrace.c (inf_ptrace_xfer_partial): Likewise. Change
type of 'partial_len' to ULONGEST.
* inf-ttrace.c (inf_ttrace_xfer_partial): Likewise.
* linux-nat.c (linux_xfer_siginfo ): Likewise.
(linux_nat_xfer_partial): Likewise.
(linux_proc_xfer_partial, linux_xfer_partial): Likewise.
(linux_proc_xfer_spu, linux_nat_xfer_osdata): Likewise.
* monitor.c (monitor_xfer_memory): Likewise.
(monitor_xfer_partial): Likewise.
* procfs.c (procfs_xfer_partial): Likewise.
* record-btrace.c (record_btrace_xfer_partial): Likewise.
* record-full.c (record_full_xfer_partial): Likewise.
(record_full_core_xfer_partial): Likewise.
* remote-sim.c (gdbsim_xfer_memory): Likewise.
(gdbsim_xfer_partial): Likewise.
* remote.c (remote_write_bytes_aux): Likewise. All callers
updated.
(remote_write_bytes, remote_read_bytes): Likewise. All
callers updated.
(remote_flash_erase): Likewise. All callers updated.
(remote_write_qxfer): Likewise. All callers updated.
(remote_read_qxfer): Likewise. All callers updated.
(remote_xfer_partial): Likewise.
* rs6000-nat.c (rs6000_xfer_partial): Likewise.
(rs6000_xfer_shared_libraries): Likewise.
* sol-thread.c (sol_thread_xfer_partial): Likewise.
(sol_thread_xfer_partial): Likewise.
* sparc-nat.c (sparc_xfer_wcookie): Likewise.
(sparc_xfer_partial): Likewise.
* spu-linux-nat.c (spu_proc_xfer_spu): Likewise. All callers
updated.
(spu_xfer_partial): Likewise.
* spu-multiarch.c (spu_xfer_partial): Likewise.
* tracepoint.c (tfile_xfer_partial): Likewise.
* windows-nat.c (windows_xfer_memory): Likewise.
(windows_xfer_shared_libraries): Likewise.
(windows_xfer_partial): Likewise.
* valprint.c: Replace 'target_xfer_error' with
'target_xfer_status' in comments.
RECORD_IS_USED and record_full_open look at current_target.to_stratum
to determine whether a record target is in use. This is wrong because
arch_stratum is greater than record_stratum, so if an arch_stratum
target is pushed, RECORD_IS_USED and record_full_open will miss it.
To fix this, we can use the existing find_record_target instead, which
looks up for a record stratum target across the target stack. Since
that means exporting find_record_target in record.h, RECORD_IS_USED
ends up redundant, so the patch eliminates it.
That exercise then reveals other issues:
- adjust_pc_after_break is gating record_full_... calls based on
RECORD_IS_USED. But, record_full_ calls shouldn't be made when
recording with the record-btrace target. So this adds a new
record_full_is_used predicate to be used in that spot.
- record_full_open says "Process record target already running", even
if the recording target is record-btrace ("process record" is the
original complete name of the record-full target). record_btrace_open
only says "The process is already being recorded." and does not
suggest "record stop", like record-full does. The patch factors out
and merges that error to a new record_preopen function that all record
targets call in their open routine.
Tested on x86_64 Fedora 17.
gdb/
2014-01-14 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* infrun.c (use_displaced_stepping): Use find_record_target
instead of RECORD_IS_USED.
(adjust_pc_after_break): Use record_full_is_used instead of
RECORD_IS_USED.
* record-btrace.c (record_btrace_open): Call record_preopen
instead of checking RECORD_IS_USED.
* record-full.c (record_full_shortname)
(record_full_core_shortname): New globals.
(record_full_is_used): New function.
(find_full_open): Call record_preopen instead of checking
RECORD_IS_USED.
(init_record_full_ops): Set the target's shortname to
record_full_shortname.
(init_record_full_core_ops): Set the target's shortname to
record_full_core_shortname.
* record-full.h (record_full_is_used): Declare.
* record.c (find_record_target): Make extern.
(record_preopen): New function.
* record.h (RECORD_IS_USED): Delete macro.
(find_record_target, record_preopen): Declare functions.
This patch adds a typedef target_xfer_partial_ftype. When we change
the signature of xfer_partial functions (for example, adding a new
parameter), we don't have to modify all of their declarations.
This patch also updates the type of parameters of target_xfer_partial
from "void *" to "gdb_byte *".
gdb:
2013-12-18 Yao Qi <yao@codesourcery.com>
* target.h (target_xfer_partial_ftype): New typedef.
(target_xfer_partial): Update declaration.
* auxv.h (memory_xfer_auxv): Likewise.
* ia64-hpux-nat.c (super_xfer_partial): Likewise.
* ia64-linux-nat.c (super_xfer_partial): Likewise.
* linux-nat.c (super_xfer_partial): Likewise.
* procfs.c (procfs_xfer_partial): Likewise.
* record-full.c (record_full_beneath_to_xfer_partial):
(tmp_to_xfer_partial): Likewise.
* sparc-nat.c (inf_ptrace_xfer_partial): Likewise.
* target.c (default_xfer_partial): Likewise.
(current_xfer_partial): Likewise.
(target_xfer_partial): Change parameter type to 'gdb_byte *'.
"info threads" changes the default source for "break" and "list", to
whatever the location of the first/bottom thread in the thread list
is...
(gdb) b start
(gdb) c
...
(gdb) list
*lists "start"*
(gdb) b 23
Breakpoint 3 at 0x400614: file test.c, line 23.
(gdb) info threads
Id Target Id Frame
* 2 Thread 0x7ffff7fcb700 (LWP 1760) "test" start (arg=0x0) at test.c:23
1 Thread 0x7ffff7fcc740 (LWP 1748) "test" 0x000000323dc08e60 in pthread_join (threadid=140737353922304, thread_return=0x0) at pthread_join.c:93
(gdb) b 23
Breakpoint 4 at 0x323dc08d90: file pthread_join.c, line 23.
^^^^^^^^^^^^^^^
(gdb) list
93 lll_wait_tid (pd->tid);
94
95
96 /* Restore cancellation mode. */
97 CANCEL_RESET (oldtype);
98
99 /* Remove the handler. */
100 pthread_cleanup_pop (0);
101
102
The issue is that print_stack_frame always sets the current sal to the
frame's sal. print_frame_info (which print_stack_frame calls to do
most of the work) also sets the last displayed sal, but only if
print_what isn't LOCATION. Now the call in question, from within
thread.c:print_thread_info, does pass in LOCATION as print_what, but
print_stack_frame doesn't have the same check print_frame_info has.
We could consider adding it, but setting these globals depending on
print_what isn't very clean, IMO. What we have is two logically
distinct operations mixed in the same function(s):
#1 - print frame, in the format specified by {print_what,
print_level and print_args}.
#2 - We're displaying a frame to the user, and I want the default
sal to point here, because the program stopped here, or the user
did some context-changing command (up, down, etc.).
So I added a new parameter to print_stack_frame & friends for point
#2, and went through all calls in the tree adjusting as necessary.
Tested on x86_64 Fedora 17.
gdb/
2013-09-17 Pedro Alves <palves@redhat.com>
PR gdb/15911
* ada-tasks.c (task_command_1): Adjust call to print_stack_frame.
* bsd-kvm.c (bsd_kvm_open, bsd_kvm_proc_cmd, bsd_kvm_pcb_cmd):
* corelow.c (core_open):
* frame.h (print_stack_frame, print_frame_info): New
'set_current_sal' parameter.
* infcmd.c (finish_command, kill_command): Adjust call to
print_stack_frame.
* inferior.c (inferior_command): Likewise.
* infrun.c (normal_stop): Likewise.
* linux-fork.c (linux_fork_context): Likewise.
* record-full.c (record_full_goto_entry, record_full_restore):
Likewise.
* remote-mips.c (common_open): Likewise.
* stack.c (print_stack_frame): New 'set_current_sal' parameter.
Use it.
(print_frame_info): New 'set_current_sal' parameter. Set the last
displayed sal depending on the new paremeter instead of looking at
print_what.
(backtrace_command_1, select_and_print_frame, frame_command)
(current_frame_command, up_command, down_command): Adjust call to
print_stack_frame.
* thread.c (print_thread_info, restore_selected_frame)
(do_captured_thread_select): Adjust call to print_stack_frame.
* tracepoint.c (tfind_1): Likewise.
* mi/mi-cmd-stack.c (mi_cmd_stack_list_frames)
(mi_cmd_stack_info_frame): Likewise.
* mi/mi-interp.c (mi_on_normal_stop): Likewise.
* mi/mi-main.c (mi_cmd_exec_return, mi_cmd_trace_find): Likewise.
gdb/testsuite/
* gdb.threads/info-threads-cur-sal-2.c: New file.
* gdb.threads/info-threads-cur-sal.c: New file.
* gdb.threads/info-threads-cur-sal.exp: New file.
Bookmarks are opaque to the core code -- by design, the target is free
to use any sort of blob as bookmark identifier.
The record target chooses to use strings for bookmarks. This adds
casts following that direction, fixing -Wpointer-sign warnings.
gdb/
2013-04-19 Pedro Alves <palves@redhat.com>
* record-full.c (record_full_get_bookmark): Change local 'ret'
type to char * and add cast to gdb_byte *.
(record_full_goto_bookmark): Handle 'bookmark' argument as a
string.
* reverse.c (goto_bookmark_command): Add casts to gdb_byte *.
Currently, several commands take "0" or "-1" to mean "unlimited".
"show" knows when to print "unlimited":
(gdb) show height
Number of lines gdb thinks are in a page is 45.
(gdb) set height 0
(gdb) show height
Number of lines gdb thinks are in a page is unlimited.
However, the user can't herself specify "unlimited" directly:
(gdb) set height unlimited
No symbol table is loaded. Use the "file" command.
(gdb)
This patch addresses that, by adjusting the set handler for all
integer/uinteger/zuinteger_unlimited commands to accept literal
"unlimited". It also installs a completer. Presently, we complete on
symbols by default, and at
<http://sourceware.org/ml/gdb-patches/2013-03/msg00864.html> I've
shown a WIP prototype that tried to keep that half working in these
commands. In the end, it turned out to be more complicated than
justifiable, IMO. It's super rare to want to pass the value of a
variable/symbol in the program to a GDB set/show knob. That'll still
work, it's just that we won't assist with completion anymore. This
patch just sticks with the simple, and completes on "unlimited", and
nothing else. This simplification means that
"set he<tab><tab>"
is all it takes to get to:
"set height unlimited"
The patch then goes through all integer/uinteger/zuinteger_unlimited
commands in the tree, and updates both the online help and the manual
to mention that "unlimited" is accepted in addition to 0/-1. In the
cases where the command had no online help text at all, this adds it.
I've tried to make the texts read in a way that "unlimited" is
suggested before "0" or "-1" is.
Tested on x86_64 Fedora 17.
gdb/
2013-04-10 Pedro Alves <palves@redhat.com>
* cli/cli-decode.c (integer_unlimited_completer): New function.
(add_setshow_integer_cmd, add_setshow_uinteger_cmd)
(add_setshow_zuinteger_unlimited_cmd): Install the "unlimited"
completer.
* cli/cli-setshow.c: Include "cli/cli-utils.h".
(is_unlimited_literal): New function.
(do_set_command): Handle literal "unlimited" arguments.
* frame.c (_initialize_frame) <set backtrace limit>: Document
"unlimited".
* printcmd.c (_initialize_printcmd) <set print
max-symbolic-offset>: Add help text.
* record-full.c (_initialize_record_full) <set record full
insn-number-max>: Likewise.
* record.c (_initialize_record) <set record
instruction-history-size, set record function-call-history-size>:
Add help text.
* ser-tcp.c (_initialize_ser_tcp) <set tcp connect-timeout>: Add
help text.
* tracepoint.c (_initialize_tracepoint) <set trace-buffer-size>:
Likewise.
* source.c (_initialize_source) <set listsize>: Add help text.
* utils.c (initialize_utils) <set height, set width>: Likewise.
<set pagination>: Mention "set height unlimited".
* valprint.c (_initialize_valprint) <set print elements, set print
repeats>: Document "unlimited".
gdb/doc/
2013-04-10 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Process Record and Replay): Document that "set
record full insn-number-max", "set record
instruction-history-size" and "set record
function-call-history-size" accept "unlimited".
(Backtrace): Document that "set backtrace limit" accepts
"unlimited".
(List): Document that "set listsize" accepts "unlimited".
(Print Settings)" Document that "set print max-symbolic-offset",
"set print elements" and "set print repeats" accept "unlimited".
(Starting and Stopping Trace Experiments): Document that "set
trace-buffer-size" accepts "unlimited".
(Remote Configuration): Document that "set tcp connect-timeout"
accepts "unlimited".
(Command History): Document that "set history size" accepts
"unlimited".
(Screen Size): Document that "set height" and "set width" accepts
"unlimited". Adjust "set pagination"'s description to suggest
"set height unlimited" instead of "set height 0".
gdb/testsuite/
2013-04-10 Pedro Alves <palves@redhat.com>
* gdb.base/completion.exp: Test "set height", "set listsize" and
"set trace-buffer-size" completion.
* gdb.base/setshow.exp: Test "set height unlimited".
* gdb.trace/trace-buffer-size.exp: Test "set trace-buffer-size
unlimited".
The "set record full insn-number-max" command is an uinteger command.
If the variable that holds the maximum count of logged instructions is
unsigned, it's better if the variable that holds the current number of
logged instructions is also unsigned. Looking over the code, there's
no case the variable could end up negative.
Then, tests like "if (record_full_insn_max_num)" are always true,
because being a uinteger command means that "set record full
insn-number-max 0" is actually mapped to UINT_MAX internally. IOW,
the command's variable is never 0. The checks might make some sense
if 0 wasn't mapped to UINT_MAX, and 0 meant unlimited, but, that's not
how things work.
Tested on x86_64 Fedora 17.
gdb/
2013-03-26 Pedro Alves <palves@redhat.com>
* record-full.c (record_full_insn_num): Make it unsigned.
(record_full_check_insn_num, record_full_message)
(record_full_registers_change, record_full_xfer_partial): Remove
record_full_insn_max_num check (it's always != 0).
(record_full_info, record_full_restore): Use %u as format string.
(): Use %u as format string.
(set_record_full_insn_max_num): Remove record_full_insn_max_num
check (it's always != 0).
between different record targets.
gdb/
* record.h (record_disconnect): New.
(record_detach): New.
(record_mourn_inferior): New.
(record_kill): New.
* record-full.c (record_disconnect, record_detach,
record_mourn_inferior, record_kill): Move to...
* record.c: ...here.
(DEBUG): New.
(record_stop): New.
(record_unpush): New.
(cmd_record_stop): Call record_stop. Replace unpush_target
call with record_unpush call.
(record_disconnect, record_detach): Assert that the target
is of record stratum. Call record_unpush, record_stop, and
DEBUG.
(record_mourn_inferior, record_kill): Assert that the target
is of record stratum. Call record_unpush and DEBUG.
gdb/
* record-full.h, record-full.c (record_memory_query): Rename
to ...
(record_full_memory_query): ...this. Update all users.
(record_arch_list_add_reg): Rename to ...
(record_full_arch_list_add_reg): ...this. Update all users.
(record_arch_list_add_mem): Rename to ...
(record_full_arch_list_add_mem): ...this. Update all users.
(record_arch_list_add_end): Rename to ...
(record_full_arch_list_add_end): ...this. Update all users.
(record_gdb_operation_disable_set): Rename to ...
(record_full_gdb_operation_disable_set): ...this.
Update all users.
