qemu/linux-user/arm
Peter Maydell 13a0c21e64 linux-user/arm: BKPT should cause SIGTRAP, not be a syscall
In linux-user/arm/cpu-loop.c we incorrectly treat EXCP_BKPT similarly
to EXCP_SWI, which means that if the guest executes a BKPT insn then
QEMU will perform a syscall for it (which syscall depends on what
value happens to be in r7...). The correct behaviour is that the
guest process should take a SIGTRAP.

This code has been like this (more or less) since commit
06c949e62a in 2006 which added BKPT in the first place.  This is
probably because at the time the same code path was used to handle
both Linux syscalls and semihosting calls, and (on M profile) BKPT
with a suitable magic number is used for semihosting calls.  But
these days we've moved handling of semihosting out to an entirely
different codepath, so we can fix this bug by simply removing this
handling of EXCP_BKPT and instead making it deliver a SIGTRAP like
EXCP_DEBUG (as we do already on aarch64).

Reported-by: <omerg681@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200420212206.12776-2-peter.maydell@linaro.org
Fixes: https://bugs.launchpad.net/qemu/+bug/1873898
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-21 20:00:18 +01:00
..
nwfpe linux-user/arm/nwfpe: Check coprocessor number for FPA emulation 2018-01-11 13:25:39 +00:00
cpu_loop.c linux-user/arm: BKPT should cause SIGTRAP, not be a syscall 2020-05-21 20:00:18 +01:00
Makefile.objs linux-user, arm: add syscall table generation support 2020-03-20 16:02:00 +01:00
semihost.c semihosting: add qemu_semihosting_console_inc for SYS_READC 2020-01-09 11:41:29 +00:00
signal.c target/arm: Add isar_feature_aa32_vfp_simd 2020-02-28 16:14:57 +00:00
sockbits.h linux-user: move socket.h generic definitions to generic/sockbits.h 2018-05-25 10:10:55 +02:00
syscall.tbl linux-user: update syscall.tbl from linux 0bf999f9c5e7 2020-03-20 16:02:00 +01:00
syscallhdr.sh linux-user, arm: add syscall table generation support 2020-03-20 16:02:00 +01:00
target_cpu.h linux-user: Introduce cpu_clone_regs_parent 2019-11-06 13:43:25 +01:00
target_elf.h linux-user: Move CPU type name selection to a function 2018-02-25 17:27:41 +01:00
target_fcntl.h linux-user: move arm/aarch64/m68k fcntl definitions to [arm|aarch64|m68k]/target_fcntl.h 2018-06-04 01:30:44 +02:00
target_signal.h linux-user: move generic signal definitions to generic/signal.h 2018-06-04 01:30:44 +02:00
target_structs.h linux-user: remove useless padding in flock64 structure 2018-05-03 18:40:19 +02:00
target_syscall.h target/arm: remove run-time semihosting checks for linux-user 2019-09-27 11:41:32 +01:00
termbits.h Supply missing header guards 2019-06-12 13:20:21 +02:00