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
