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[patch/rfc/6.2] Update status of signal handlers
- From: Andrew Cagney <cagney at gnu dot org>
- To: gdb-patches at sources dot redhat dot com
- Cc: Ulrich Weigand <Ulrich dot Weigand at de dot ibm dot com>
- Date: Mon, 19 Jul 2004 13:23:31 -0400
- Subject: [patch/rfc/6.2] Update status of signal handlers
Hello,
This updates the news about signal handlers adding more current information.
comments?
Andrew
PS: Yes, the s390 is the only Linux kernel known to work.
2004-07-19 Andrew Cagney <cagney@gnu.org>
* PROBLEMS: Mention breakpoints/1702.
* NEWS: For signal trampolines, cite s390 GNU/Linux as a system
that is known to work.
Index: NEWS
===================================================================
RCS file: /cvs/src/src/gdb/NEWS,v
retrieving revision 1.154.2.3
diff -p -u -r1.154.2.3 NEWS
--- NEWS 17 Jul 2004 14:49:08 -0000 1.154.2.3
+++ NEWS 19 Jul 2004 17:18:37 -0000
@@ -36,8 +36,9 @@ of sa_sigaction signal trampolines; back
call; backtrace through a signal trampoline; step into and out of
signal handlers; and single-stepping in the signal trampoline.
-These fixes were tested on i386 GNU/Linux systems that include a 2.4
-kernel.
+Please note that kernel bugs are a limiting factor here. These
+features have been shown to work on an s390 GNU/Linux system that
+include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
* Cygwin support for DWARF 2 added.
Index: PROBLEMS
===================================================================
RCS file: /cvs/src/src/gdb/PROBLEMS,v
retrieving revision 1.31.2.1
diff -p -u -r1.31.2.1 PROBLEMS
--- PROBLEMS 17 Jul 2004 14:49:08 -0000 1.31.2.1
+++ PROBLEMS 19 Jul 2004 17:18:37 -0000
@@ -94,6 +94,19 @@ implement virtual base classes. gcc 2.x
function with a hidden parameter, but gcc 3.x conforms to a multi-vendor
ABI for C++ which requires multiple object code functions.
+*** Signal handlers
+
+On many systems an attempt to single-step a system-call instruction
+results in two or more instructions being executed (the system-call,
+and one or more instructions following).
+
+When attempting to single-step through a signal trampoline, this
+problem may result the program unintentionally running to completion,
+or re-execute the faulting instruction, or even corrupting the program
+counter.
+
+Ref: PR breakpoints/1702.
+
*** Stack backtraces
GDB's core code base has been updated to use a new backtrace