From 3dc9dde26d1c279e888d1fd0361f720e5a3721f3 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 7 Nov 2022 09:55:23 -0500 Subject: [PATCH] gdb: add prepare_reinflate/reinflate around print_frame_args in info_frame_command_core I noticed this crash: $ ./gdb --data-directory=data-directory -nx -q \ testsuite/outputs/gdb.python/pretty-print-call-by-hand/pretty-print-call-by-hand \ -x testsuite/outputs/gdb.python/pretty-print-call-by-hand/pretty-print-call-by-hand.py \ -ex "b g" -ex r (gdb) info frame Stack level 0, frame at 0x7fffffffdd80: rip = 0x555555555160 in g (/home/simark/src/binutils-gdb/gdb/testsuite/gdb.python/pretty-print-call-by-hand.c:41); saved rip = 0x5555555551a3 called by frame at 0x7fffffffdda0 source language c. Arglist at 0x7fffffffdd70, args: mt=mytype is 0x555555556004 "hello world", depth=10 Fatal signal: Segmentation fault This is another case of frame_info being invalidated under a function's feet. The stack trace when the frame_info get invalidated looks like: ... many frames to pretty print the arg, that eventually invalidate the frame_infos ... #35 0x00005568d0a8ab24 in print_frame_arg (fp_opts=..., arg=0x7ffc3216bcb0) at /home/simark/src/binutils-gdb/gdb/stack.c:489 #36 0x00005568d0a8cc75 in print_frame_args (fp_opts=..., func=0x621000233210, frame=..., num=-1, stream=0x60b000000300) at /home/simark/src/binutils-gdb/gdb/stack.c:898 #37 0x00005568d0a9536d in info_frame_command_core (fi=..., selected_frame_p=true) at /home/simark/src/binutils-gdb/gdb/stack.c:1682 print_frame_args knows that print_frame_arg can invalidate frame_info objects, and therefore calls prepare_reinflate/reinflate. However, info_frame_command_core has a separate frame_info_ptr instance (it is passed by value / copy). So info_frame_command_core needs to know that print_frame_args can invalidate frame_info objects, and therefore needs to prepare_reinflate/reinflate as well. Add those calls, and enhance the gdb.python/pretty-print-call-by-hand.exp test to test that command. Reviewed-By: Bruno Larsen Change-Id: I9edaae06d62e97ffdb30938d364437737238a960 --- gdb/stack.c | 4 ++++ gdb/testsuite/gdb.python/pretty-print-call-by-hand.exp | 8 ++++++++ 2 files changed, 12 insertions(+) diff --git a/gdb/stack.c b/gdb/stack.c index 653251c200b..4e2342c2a8d 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -1679,8 +1679,12 @@ info_frame_command_core (frame_info_ptr fi, bool selected_frame_p) else gdb_printf (" %d args: ", numargs); } + + fi.prepare_reinflate (); print_frame_args (user_frame_print_options, func, fi, numargs, gdb_stdout); + fi.reinflate (); + gdb_puts ("\n"); } } diff --git a/gdb/testsuite/gdb.python/pretty-print-call-by-hand.exp b/gdb/testsuite/gdb.python/pretty-print-call-by-hand.exp index 0aeb2218f91..eb3fc9e35fa 100644 --- a/gdb/testsuite/gdb.python/pretty-print-call-by-hand.exp +++ b/gdb/testsuite/gdb.python/pretty-print-call-by-hand.exp @@ -98,6 +98,14 @@ with_test_prefix "frame print" { "backtrace test" } } + +# Test the "info frame" command +with_test_prefix "info frame" { + if { [start_test "TAG: first frame"] == 0 } { + gdb_test "info frame" "mytype is $hex \"hello world\".*" + } +} + # Testing the down command. with_test_prefix "frame movement down" { if { [start_test "TAG: first frame"] == 0 } { -- 2.30.2