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[PATCH] bug fix for gdb 16039
- From: "Dave.Tian" <xhengdf at gmail dot com>
- To: gdb-patches at sourceware dot org
- Cc: sergiodj at redhat dot com, "Dave.Tian" <xhengdf at gmail dot com>
- Date: Wed, 16 Oct 2013 10:18:18 +0800
- Subject: [PATCH] bug fix for gdb 16039
- Authentication-results: sourceware.org; auth=none
1 Description: Gdb bug 16039 created by me
Title: Gdb next" command stop working when shared library unloaded.
Root Cause: There is "libc++" static linked into the shared library,
and since gdb insert internal breakpoints on std::terminate/longjump/...
so after dlclose, the memory address is
invalid,remove_breakpoints/insert_breakpoints
failed with EIO error.
Fix: Disable the internal breakpoints when dlclose hit.
2 ChangeLog:
2013-10-16 Tian Ye <xhengdf@gmail.com>
PR gdb/16039
* breakpoint.c (is_removable_in_unloaded_shlib): New.
(set_longjmp_breakpoint): Check if breakpoint's location
address is not in an unloaded shared library
(disable_breakpoints_in_unloaded_shlib): Disable the
internal breakpoints in the hook function of shared
library unload.
3 Patch Diffs:
--- breakpoint.c.bak 2013-10-12 01:15:09.044081000 -0700
+++ breakpoint.c 2013-10-15 18:50:59.842116000 -0700
@@ -1118,6 +1118,17 @@ is_tracepoint (const struct breakpoint *
return is_tracepoint_type (b->type);
}
+/* Breakpoints should be disable when shlib unload. */
+
+static int
+is_removable_in_unloaded_shlib(const struct breakpoint *b)
+{
+ return (b->type == bp_longjmp_master
+ || b->type == bp_std_terminate_master
+ || b->type == bp_exception_master
+ || b->type == bp_exception);
+}
+
/* A helper function that validates that COMMANDS are valid for a
breakpoint. This function will throw an exception if a problem is
found. */
@@ -7147,8 +7158,8 @@ set_longjmp_breakpoint (struct thread_in
clones of those and enable them for the requested thread. */
ALL_BREAKPOINTS_SAFE (b, b_tmp)
if (b->pspace == current_program_space
- && (b->type == bp_longjmp_master
- || b->type == bp_exception_master))
+ && ((b->type == bp_longjmp_master
+ || b->type == bp_exception_master) && !b->loc->shlib_disabled))
{
enum bptype type = b->type == bp_longjmp_master ? bp_longjmp : bp_exception;
struct breakpoint *clone;
@@ -7463,7 +7474,8 @@ disable_breakpoints_in_unloaded_shlib (s
|| b->type == bp_hardware_breakpoint)
&& (loc->loc_type == bp_loc_hardware_breakpoint
|| loc->loc_type == bp_loc_software_breakpoint))
- || is_tracepoint (b))
+ || is_tracepoint (b)
+ || is_removable_in_unloaded_shlib(b))
&& solib_contains_address_p (solib, loc->address))
{
loc->shlib_disabled = 1;