acrn-kernel/arch/s390/kernel
Heiko Carstens 7a4d6481fb s390/ptrace: handle setting of fpc register correctly
[ Upstream commit 8b13601d19c541158a6e18b278c00ba69ae37829 ]

If the content of the floating point control (fpc) register of a traced
process is modified with the ptrace interface the new value is tested for
validity by temporarily loading it into the fpc register.

This may lead to corruption of the fpc register of the tracing process:
if an interrupt happens while the value is temporarily loaded into the
fpc register, and within interrupt context floating point or vector
registers are used, the current fp/vx registers are saved with
save_fpu_regs() assuming they belong to user space and will be loaded into
fp/vx registers when returning to user space.

test_fp_ctl() restores the original user space fpc register value, however
it will be discarded, when returning to user space.

In result the tracer will incorrectly continue to run with the value that
was supposed to be used for the traced process.

Fix this by saving fpu register contents with save_fpu_regs() before using
test_fp_ctl().

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:49 +00:00
..
syscalls
vdso32
vdso64
.gitignore
Makefile rethook, fprobe: do not trace rethook related functions 2023-05-24 17:32:53 +01:00
abs_lowcore.c
alternative.c
asm-offsets.c
audit.c
audit.h
cache.c
compat_audit.c
compat_linux.c
compat_linux.h
compat_ptrace.h
compat_signal.c
cpcmd.c
cpufeature.c
crash_dump.c
debug.c
diag.c
dis.c
dumpstack.c
early.c
early_printk.c
earlypgm.S
ebcdic.c
entry.S
entry.h
fpu.c
ftrace.c
ftrace.h
guarded_storage.c
head64.S
idle.c
ima_arch.c
ipl.c s390/ipl: add missing secure/has_secure file to ipl type 'unknown' 2023-09-13 09:43:03 +02:00
ipl_vmparm.c
irq.c
jump_label.c
kdebugfs.c
kexec_elf.c
kexec_image.c
kprobes.c
kprobes_insn_page.S
lgr.c
machine_kexec.c
machine_kexec_file.c
machine_kexec_reloc.c
mcount.S
module.c
nmi.c
nospec-branch.c
nospec-sysfs.c
numa.c
os_info.c
perf_cpum_cf.c s390/cpumf: support user space events for counting 2024-01-10 17:10:30 +01:00
perf_cpum_cf_common.c
perf_cpum_cf_events.c
perf_cpum_sf.c
perf_event.c
perf_pai_crypto.c
perf_pai_ext.c
perf_regs.c
process.c
processor.c
ptrace.c s390/ptrace: handle setting of fpc register correctly 2024-02-05 20:12:49 +00:00
reipl.S
relocate_kernel.S
runtime_instr.c
setup.c
signal.c
smp.c
stacktrace.c
sthyi.c KVM: s390: fix sthyi error handling 2023-08-11 12:08:11 +02:00
syscall.c
sysinfo.c
text_amode31.S
time.c
topology.c s390/topology: honour nr_cpu_ids when adding CPUs 2023-06-09 10:34:13 +02:00
trace.c
traps.c
unwind_bc.c
uprobes.c
uv.c
vdso.c
vmlinux.lds.S
vtime.c