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[Qemu-devel] [PATCH 0/2] linux-user: Don't call gdb_handlesig unnecessar
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 0/2] linux-user: Don't call gdb_handlesig unnecessarily |
Date: |
Fri, 19 Oct 2018 18:49:56 +0100 |
This patchset fixes a minor bug in our handling of SIGTRAP
in linux-user.
The CPU main-loop routines for linux-user generally call
gdb_handlesig() when they're about to queue a SIGTRAP signal. This
is wrong, because queue_signal() will cause us to pend a signal, and
process_pending_signals() will then call gdb_handlesig() itself. So
the effect is that we notify gdb of the SIGTRAP, and then if gdb says
"OK, continue with signal X" we will incorrectly notify gdb of the
signal X as well. We don't do this double-notify for anything else,
only SIGTRAP.
This bug only manifests if the user responds to the reported SIGTRAP
using "signal SIGFOO" rather than "continue"; since the latter is the
overwhelmingly common thing to do after a breakpoint most people
won't have hit this.
Patch 1 fixes this bug for every target except nios2, by
deleting the incorrect code.
Patch 2 fixes nios2 separately, because it was doing some odd
things with gdb_handlesig(). This also fixes in passing a Coverity
issue.
Tested with "make check-tcg", and with some by-hand stepping
around with an attached gdb. NB that the nios2 patch is only
compile tested as I don't have a nios2 linux-user environment
and check-tcg doesn't cover it.
thanks
-- PMM
Peter Maydell (2):
linux-user: Don't call gdb_handlesig() before queue_signal()
linux-user: Clean up nios2 main loop signal handling
linux-user/aarch64/cpu_loop.c | 13 +++++--------
linux-user/alpha/cpu_loop.c | 12 ++++--------
linux-user/arm/cpu_loop.c | 16 ++++------------
linux-user/cris/cpu_loop.c | 16 ++++------------
linux-user/hppa/cpu_loop.c | 11 ++++-------
linux-user/i386/cpu_loop.c | 16 ++++------------
linux-user/m68k/cpu_loop.c | 16 ++++------------
linux-user/microblaze/cpu_loop.c | 16 ++++------------
linux-user/mips/cpu_loop.c | 16 ++++------------
linux-user/nios2/cpu_loop.c | 14 +++++---------
linux-user/openrisc/cpu_loop.c | 11 ++++-------
linux-user/ppc/cpu_loop.c | 15 +++++----------
linux-user/riscv/cpu_loop.c | 2 +-
linux-user/s390x/cpu_loop.c | 9 +++------
linux-user/sh4/cpu_loop.c | 17 ++++-------------
linux-user/sparc/cpu_loop.c | 16 ++++------------
linux-user/xtensa/cpu_loop.c | 11 ++++-------
17 files changed, 67 insertions(+), 160 deletions(-)
--
2.19.1
- [Qemu-devel] [PATCH 0/2] linux-user: Don't call gdb_handlesig unnecessarily,
Peter Maydell <=