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authorBoqun Feng <boqun.feng@gmail.com>2018-06-02 15:44:01 +0300
committerThomas Gleixner <tglx@linutronix.de>2018-06-06 12:58:33 +0300
commit6f37be4b1364ee6521625195ef199c73c60d96ff (patch)
tree03fb9633a4ecc0d45d3129a1d407fb3257a5884c /arch/powerpc
parent8a417c48fa68b37bc6e8790414224e2cf91c4a5e (diff)
downloadlinux-6f37be4b1364ee6521625195ef199c73c60d96ff.tar.xz
powerpc: Add syscall detection for restartable sequences
Syscalls are not allowed inside restartable sequences, so add a call to rseq_syscall() at the very beginning of system call exiting path for CONFIG_DEBUG_RSEQ=y kernel. This could help us to detect whether there is a syscall issued inside restartable sequences. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-10-mathieu.desnoyers@efficios.com
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/entry_32.S7
-rw-r--r--arch/powerpc/kernel/entry_64.S8
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index eb8d01bae8c6..973577f2141c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -365,6 +365,13 @@ syscall_dotrace_cont:
blrl /* Call handler */
.globl ret_from_syscall
ret_from_syscall:
+#ifdef CONFIG_DEBUG_RSEQ
+ /* Check whether the syscall is issued inside a restartable sequence */
+ stw r3,GPR3(r1)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl rseq_syscall
+ lwz r3,GPR3(r1)
+#endif
mr r6,r3
CURRENT_THREAD_INFO(r12, r1)
/* disable interrupts so current_thread_info()->flags can't change */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 51695608c68b..1c374387656a 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -184,6 +184,14 @@ system_call: /* label this so stack traces look sane */
.Lsyscall_exit:
std r3,RESULT(r1)
+
+#ifdef CONFIG_DEBUG_RSEQ
+ /* Check whether the syscall is issued inside a restartable sequence */
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl rseq_syscall
+ ld r3,RESULT(r1)
+#endif
+
CURRENT_THREAD_INFO(r12, r1)
ld r8,_MSR(r1)