From b14185ce104d07ddcc1c86c08c10888ecd63292c Mon Sep 17 00:00:00 2001 From: Andrew Cagney Date: Tue, 25 Feb 2003 23:52:16 +0000 Subject: 2003-02-25 Andrew Cagney * frame.c (get_prev_frame): Add comment on check for inside_entry_func. Only check for inside_entry_file when not a dummy and not a sentinel. Check that the new frame is not inner to the old frame. --- gdb/ChangeLog | 7 +++++++ gdb/frame.c | 42 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 47 insertions(+), 2 deletions(-) (limited to 'gdb') diff --git a/gdb/ChangeLog b/gdb/ChangeLog index cc5bbf0..e775420 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,12 @@ 2003-02-25 Andrew Cagney + * frame.c (get_prev_frame): Add comment on check for + inside_entry_func. Only check for inside_entry_file when not a + dummy and not a sentinel. Check that the new frame is not inner + to the old frame. + +2003-02-25 Andrew Cagney + * frame.c (frame_debug): New variable. (_initialize_frame): Add "set/show debug frame" command. (get_prev_frame): When frame_debug, print reason why unwind diff --git a/gdb/frame.c b/gdb/frame.c index c4c40d5..a0e9a7d 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1239,7 +1239,10 @@ get_prev_frame (struct frame_info *next_frame) return next_frame->prev; next_frame->prev_p = 1; - /* If we're inside the entry file, it isn't valid. */ + /* If we're inside the entry file, it isn't valid. Don't apply this + test to a dummy frame - dummy frame PC's typically land in the + entry file. Don't apply this test to the sentinel frame. + Sentinel frames should always be allowed to unwind. */ /* NOTE: drow/2002-12-25: should there be a way to disable this check? It assumes a single small entry file, and the way some debug readers (e.g. dbxread) figure out which object is the @@ -1247,7 +1250,8 @@ get_prev_frame (struct frame_info *next_frame) /* NOTE: cagney/2003-01-10: If there is a way of disabling this test then it should probably be moved to before the ->prev_p test, above. */ - if (inside_entry_file (get_frame_pc (next_frame))) + if (next_frame->type != DUMMY_FRAME && next_frame->level >= 0 + && inside_entry_file (get_frame_pc (next_frame))) { if (frame_debug) fprintf_unfiltered (gdb_stdlog, @@ -1255,6 +1259,23 @@ get_prev_frame (struct frame_info *next_frame) return NULL; } + /* If we're already inside the entry function for the main objfile, + then it isn't valid. Don't apply this test to a dummy frame - + dummy frame PC's typically land in the entry func. Don't apply + this test to the sentinel frame. Sentinel frames should always + be allowed to unwind. */ + /* NOTE: cagney/2003-02-25: Don't enable until someone has found + hard evidence that this is needed. */ + if (0 + && next_frame->type != DUMMY_FRAME && next_frame->level >= 0 + && inside_entry_func (get_frame_pc (next_frame))) + { + if (frame_debug) + fprintf_unfiltered (gdb_stdlog, + "Outermost frame - inside entry func\n"); + return NULL; + } + /* If any of the old frame initialization methods are around, use the legacy get_prev_frame method. Just don't try to unwind a sentinel frame using that method - it doesn't work. All sentinal @@ -1324,6 +1345,9 @@ get_prev_frame (struct frame_info *next_frame) /* FIXME: cagney/2002-12-18: Instead of this hack, should just save the frame ID directly. */ struct frame_id id = frame_id_unwind (next_frame); + /* Check that the unwound ID is valid. As of 2003-02-24 the + x86-64 was returning an invalid frame ID when trying to do an + unwind a sentinel frame that belonged to a frame dummy. */ if (!frame_id_p (id)) { if (frame_debug) @@ -1331,6 +1355,20 @@ get_prev_frame (struct frame_info *next_frame) "Outermost frame - unwound frame ID invalid\n"); return NULL; } + /* Check that the new frame isn't inner to (younger, below, next) + the old frame. If that happens the frame unwind is going + backwards. */ + /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since that + doesn't have a valid frame ID. Should instead set the sentinel + frame's frame ID to a `sentinel'. Leave it until after the + switch to storing the frame ID, instead of the frame base, in + the frame object. */ + if (next_frame->level >= 0 + && frame_id_inner (id, get_frame_id (next_frame))) + error ("Unwound frame inner-to selected frame (corrupt stack?)"); + /* Note that, due to frameless functions, the stronger test of the + new frame being outer to the old frame can't be used - + frameless functions differ by only their PC value. */ prev_frame->frame = id.base; } -- cgit v1.1