linux_dsm_epyc7002/arch/s390
Masami Hiramatsu cce188bd58 bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe
Clear current_kprobe and enable preemption in kprobe
even if pre_handler returns !0.

This simplifies function override using kprobes.

Jprobe used to require to keep the preemption disabled and
keep current_kprobe until it returned to original function
entry. For this reason kprobe_int3_handler() and similar
arch dependent kprobe handers checks pre_handler result
and exit without enabling preemption if the result is !0.

After removing the jprobe, Kprobes does not need to
keep preempt disabled even if user handler returns !0
anymore.

But since the function override handler in error-inject
and bpf is also returns !0 if it overrides a function,
to balancing the preempt count, it enables preemption
and reset current kprobe by itself.

That is a bad design that is very buggy. This fixes
such unbalanced preempt-count and current_kprobes setting
in kprobes, bpf and error-inject.

Note: for powerpc and x86, this removes all preempt_disable
from kprobe_ftrace_handler because ftrace callbacks are
called under preempt disabled.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942494574.15209.12323837825873032258.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:33:19 +02:00
..
appldata treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
boot s390/boot: remove unused COMPILE_VERSION and ccflags-y 2018-04-16 09:10:24 +02:00
configs s390: update defconfigs 2018-04-27 06:51:31 +02:00
crypto s390/archrandom: Rework arch random implementation. 2018-05-30 11:18:04 +02:00
hypfs treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
include s390/kprobes: Remove jprobe implementation 2018-06-21 12:33:10 +02:00
kernel bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
kvm - Error path bug fix for overflow tests (Dan) 2018-06-12 18:28:00 -07:00
lib s390: introduce compile time check for empty .bss section 2018-05-09 10:55:01 +02:00
mm - Error path bug fix for overflow tests (Dan) 2018-06-12 18:28:00 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
numa s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
oprofile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
purgatory s390/purgatory: Fix endless interrupt loop 2018-05-18 07:24:35 +02:00
scripts s390: introduce compile time check for empty .bss section 2018-05-09 10:55:01 +02:00
tools KVM: s390: implement CPU model only facilities 2018-03-09 09:44:17 +00:00
defconfig s390: update defconfig 2018-04-16 10:29:34 +02:00
Kbuild s390/kexec_file: Add purgatory 2018-04-16 09:10:22 +02:00
Kconfig mm: introduce ARCH_HAS_PTE_SPECIAL 2018-06-07 17:34:35 -07:00
Kconfig.debug License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile kbuild: add endianness flag to CHEKCFLAGS 2018-05-29 22:05:08 +09:00