| Summary: |
gdb segfaults while using strace command with no arguments |
| Product: |
gdb
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Reporter: |
Dennis Francis <dennisfrancis.in> |
| Component: |
breakpoints | Assignee: |
Not yet assigned to anyone <unassigned> |
| Status: |
RESOLVED
FIXED
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| Severity: |
normal
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CC: |
calimeroteknik, degeneracypressure, dennisfrancis.in, marc.khouzam, pedro
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| Priority: |
P2
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| Version: |
HEAD | |
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| Target Milestone: |
7.2 | |
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Host:
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Linux myhost 2.6.35-ARCH #1 SMP PREEMPT i686 Intel(R) Core(TM)2 Duo CPU T6570 @ 2.10GHz GenuineIntel GNU/Linux
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Target:
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i686-pc-linux-gnu
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|---|
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Build:
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7.2.0.20101112
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Last reconfirmed:
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| Attachments: |
Screen dump of debug procedure; Backtrace of gdb using gdb
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Created attachment 5120 [details] Screen dump of debug procedure; Backtrace of gdb using gdb Steps to reproduce ------------------ 1. Start gdb 2. Load and start any arbitrary binary. 3. Issue the command 'strace' without any args ---> gdb segfaults ! As per GDB's internal doc """ (gdb) help strace Set a static tracepoint at specified line, function or marker. strace [LOCATION] [if CONDITION] ..... ..... With no LOCATION, uses current execution address of the selected stack frame """ Debug gdb using gdb -------------------- 1. Created a simple binary "trivial" 2. Started gdb 3. load and run gdb 3.1. Load and start "trivial" 3.2. issue 'strace' command ....<segfaults> 4. run bt [See the attachment for the complete screen dump] Backtrace generated in the parent gdb after the segfault --------------------------------------------------------- #0 0xb7cca90d in strncmp () from /lib/libc.so.6 #1 0x08109ebd in create_breakpoint (gdbarch=0x8542578, arg=0x0, cond_string=0x0, thread=0, parse_condition_and_thread=1, tempflag=0, type_wanted=bp_static_tracepoint, ignore_count=0, pending_break_support=AUTO_BOOLEAN_AUTO, ops=0x0, from_tty=1, enabled=1) at breakpoint.c:7475 #2 0x0810f7cf in strace_command (arg=0x0, from_tty=1) at breakpoint.c:10908 #3 0x080c4beb in do_cfunc (c=0x8452368, args=0x0, from_tty=1) at ./cli/cli-decode.c:67 #4 0x080c72cb in cmd_func (cmd=0x8452368, args=0x0, from_tty=1) at ./cli/cli-decode.c:1771 #5 0x080578dd in execute_command (p=0x84309d6 "", from_tty=1) at top.c:422 #6 0x0816f27a in command_handler (command=0x84309d0 "strace") at event-top.c:498 #7 0x0816f7de in command_line_handler (rl=0x8511b48 "\300\241X\b(\033Q\b") at event-top.c:702 #8 0x0825992b in rl_callback_read_char () at callback.c:205 #9 0x0816e9e7 in rl_callback_read_char_wrapper (client_data=0x0) at event-top.c:178 #10 0x0816f172 in stdin_event_handler (error=0, client_data=0x0) at event-top.c:433 #11 0x0816deaa in handle_file_event (data=...) at event-loop.c:817 #12 0x0816d6ed in process_event () at event-loop.c:399 #13 0x0816d7b2 in gdb_do_one_event (data=0x0) at event-loop.c:464 #14 0x0816864a in catch_errors (func=0x816d6fb <gdb_do_one_event>, func_args=0x0, errstring=0x832968b "", mask=6) at exceptions.c:518 #15 0x080d9f48 in tui_command_loop (data=0x0) at ./tui/tui-interp.c:171 #16 0x08168d16 in current_interp_command_loop () at interps.c:291 #17 0x0804ebee in captured_command_loop (data=0x0) at ./main.c:227 #18 0x0816864a in catch_errors (func=0x804ebe3 <captured_command_loop>, func_args=0x0, errstring=0x830ac06 "", mask=6) at exceptions.c:518 #19 0x0804fa7e in captured_main (data=0xbffff480) at ./main.c:910 #20 0x0816864a in catch_errors (func=0x804ec24 <captured_main>, func_args=0xbffff480, errstring=0x830ac06 "", mask=6) at exceptions.c:518 #21 0x0804fab4 in gdb_main (args=0xbffff480) at ./main.c:919 #22 0x0804e973 in main (argc=1, argv=0xbffff544) at gdb.c:34 Looks like strncpy() dereferences the null pointer arg I haven't tried any previous versions for the same issue.