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[PATCH] S390: Add use of unavailable-stack frame ID
- From: Andreas Arnez <arnez at linux dot vnet dot ibm dot com>
- To: gdb-patches at sourceware dot org
- Date: Mon, 07 Mar 2016 11:19:57 +0100
- Subject: [PATCH] S390: Add use of unavailable-stack frame ID
- Authentication-results: sourceware.org; auth=none
When determining the frame ID of an inline frame, GDB currently asserts
that a valid ID of the underlying real frame is found, and that it does
not match outer_frame_id. From inline_frame_this_id():
/* For now, require we don't match outer_frame_id either (see
comment above). */
gdb_assert (!frame_id_eq (*this_id, outer_frame_id));
However, this assertion may fail when the real frame's unwinder can not
determine the frame ID. This happened on an s390x target with a binary
that lacked call frame information and also confused the prologue
analyzer, because then s390_frame_this_id() left the frame ID at its
default.
To fix this, this change enhances s390_frame_this_id such that an
unavailable-stack frame ID is built if no frame base can be determined
but the function address is available.
gdb/ChangeLog:
* s390-linux-tdep.c (s390_prologue_frame_unwind_cache): Store
frame func's PC in info->func before any other failure can occur.
(s390_frame_this_id): Use frame_id_build_unavailable_stack if
info->func has been filled out.
---
gdb/s390-linux-tdep.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c
index 7f860b6..155bc66 100644
--- a/gdb/s390-linux-tdep.c
+++ b/gdb/s390-linux-tdep.c
@@ -2011,9 +2011,12 @@ s390_prologue_frame_unwind_cache (struct frame_info *this_frame,
bother searching for it -- with modern compilers this would be mostly
pointless anyway. Trust that we'll either have valid DWARF-2 CFI data
or else a valid backchain ... */
- func = get_frame_func (this_frame);
- if (!func)
- return 0;
+ if (!get_frame_func_if_available (this_frame, &info->func))
+ {
+ info->func = -1;
+ return 0;
+ }
+ func = info->func;
/* Try to analyze the prologue. */
result = s390_analyze_prologue (gdbarch, func,
@@ -2167,7 +2170,6 @@ s390_prologue_frame_unwind_cache (struct frame_info *this_frame,
info->local_base = prev_sp - size;
}
- info->func = func;
return 1;
}
@@ -2267,7 +2269,11 @@ s390_frame_this_id (struct frame_info *this_frame,
= s390_frame_unwind_cache (this_frame, this_prologue_cache);
if (info->frame_base == -1)
- return;
+ {
+ if (info->func != -1)
+ *this_id = frame_id_build_unavailable_stack (info->func);
+ return;
+ }
*this_id = frame_id_build (info->frame_base, info->func);
}
--
2.3.0