Masami Hiramatsu b3980e4852 arm64: kprobes: Recover pstate.D in single-step exception handler ... kprobes manipulates the interrupted PSTATE for single step, and doesn't restore it. Thus, if we put a kprobe where the pstate.D (debug) masked, the mask will be cleared after the kprobe hits. Moreover, in the most complicated case, this can lead a kernel crash with below message when a nested kprobe hits. [ 152.118921] Unexpected kernel single-step exception at EL1 When the 1st kprobe hits, do_debug_exception() will be called. At this point, debug exception (= pstate.D) must be masked (=1). But if another kprobes hits before single-step of the first kprobe (e.g. inside user pre_handler), it unmask the debug exception (pstate.D = 0) and return. Then, when the 1st kprobe setting up single-step, it saves current DAIF, mask DAIF, enable single-step, and restore DAIF. However, since "D" flag in DAIF is cleared by the 2nd kprobe, the single-step exception happens soon after restoring DAIF. This has been introduced by commit 7419333fa1 ("arm64: kprobe: Always clear pstate.D in breakpoint exception handler") To solve this issue, this stores all DAIF bits and restore it after single stepping. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Fixes: 7419333fa1 ("arm64: kprobe: Always clear pstate.D in breakpoint exception handler") Reviewed-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>		2019-08-02 11:55:50 +01:00
..
probes	arm64: kprobes: Recover pstate.D in single-step exception handler	2019-08-02 11:55:50 +01:00
vdso	arm64: vdso: Cleanup Makefiles	2019-07-22 10:37:33 +01:00
vdso32	arm64: vdso: Cleanup Makefiles	2019-07-22 10:37:33 +01:00
.gitignore
acpi_numa.c
acpi_parking_protocol.c
acpi.c
alternative.c
armv8_deprecated.c
asm-offsets.c
cacheinfo.c
cpu_errata.c
cpu_ops.c
cpu-reset.h
cpu-reset.S
cpufeature.c	arm64: cpufeature: Fix feature comparison for CTR_EL0.{CWG,ERG}	2019-07-31 18:10:55 +01:00
cpuidle.c
cpuinfo.c
crash_core.c
crash_dump.c
debug-monitors.c	arm64: Remove unneeded rcu_read_lock from debug handlers	2019-08-01 15:00:27 +01:00
efi-entry.S
efi-header.S
efi-rt-wrapper.S
efi.c
entry-fpsimd.S
entry-ftrace.S
entry.S	arm64: entry: SP Alignment Fault doesn't write to FAR_EL1	2019-07-22 16:22:34 +01:00
fpsimd.c	arm64/sve: Fix a couple of magic numbers for the Z-reg count	2019-07-22 11:49:03 +01:00
ftrace.c
head.S
hibernate-asm.S
hibernate.c
hw_breakpoint.c	arm64: hw_breakpoint: Fix warnings about implicit fallthrough	2019-07-29 11:59:15 +01:00
hyp-stub.S
image.h
insn.c
io.c
irq.c
jump_label.c
kaslr.c
kexec_image.c
kgdb.c
kuser32.S
machine_kexec_file.c
machine_kexec.c
Makefile
module-plts.c
module.c	arm64: module: Mark expected switch fall-through	2019-07-29 11:59:36 +01:00
module.lds
paravirt.c
pci.c
perf_callchain.c	arm64: stacktrace: Factor out backtrace initialisation	2019-07-22 11:44:08 +01:00
perf_event.c
perf_regs.c
pointer_auth.c
process.c	arm64: Force SSBS on context switch	2019-07-22 15:24:16 +01:00
psci.c
ptrace.c
reloc_test_core.c
reloc_test_syms.S
relocate_kernel.S
return_address.c	arm64: unwind: Prohibit probing on return_address()	2019-08-01 15:00:26 +01:00
sdei.c
setup.c
signal32.c
signal.c
sigreturn32.S
sleep.S
smccc-call.S
smp_spin_table.c
smp.c	arm64: smp: Mark expected switch fall-through	2019-07-29 11:59:30 +01:00
ssbd.c
stacktrace.c	arm64: unwind: Prohibit probing on return_address()	2019-08-01 15:00:26 +01:00
suspend.c
sys32.c
sys_compat.c
sys.c
syscall.c
time.c	arm64: stacktrace: Factor out backtrace initialisation	2019-07-22 11:44:08 +01:00
topology.c
trace-events-emulation.h
traps.c	arm64: stacktrace: Factor out backtrace initialisation	2019-07-22 11:44:08 +01:00
vdso.c
vmlinux.lds.S