Vineet Gupta 01b636cbc4 ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE ... commit 00fdec98d9 upstream. Trap handler for syscall tracing reads EFA (Exception Fault Address), in case strace wants PC of trap instruction (EFA is not part of pt_regs as of current code). However this EFA read is racy as it happens after dropping to pure kernel mode (re-enabling interrupts). A taken interrupt could context-switch, trigger a different task's trap, clobbering EFA for this execution context. Fix this by reading EFA early, before re-enabling interrupts. A slight side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler. The trap handler is common to both ARCompact and ARCv2 builds too. This just came out of code rework/review and no real problem was reported but is clearly a potential problem specially for strace. Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-07-16 08:17:27 +02:00
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.gitignore
arc_hostlink.c
arcksyms.c
asm-offsets.c
ctx_sw_asm.S
ctx_sw.c
devtree.c
disasm.c
entry-arcv2.S
entry-compact.S
entry.S
fpu.c
head.S
intc-arcv2.c
intc-compact.c
irq.c
kgdb.c
kprobes.c
Makefile
mcip.c
module.c
perf_event.c
process.c
ptrace.c
reset.c
setup.c
signal.c
smp.c
stacktrace.c
sys.c
traps.c
troubleshoot.c
unaligned.c
unwind.c
vmlinux.lds.S