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authorBoqun Feng <[email protected]>2018-06-02 08:44:01 -0400
committerThomas Gleixner <[email protected]>2018-06-06 11:58:33 +0200
commit6f37be4b1364ee6521625195ef199c73c60d96ff (patch)
tree03fb9633a4ecc0d45d3129a1d407fb3257a5884c
parent8a417c48fa68b37bc6e8790414224e2cf91c4a5e (diff)
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 <[email protected]> Signed-off-by: Mathieu Desnoyers <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Dave Watson <[email protected]> Cc: Will Deacon <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: Chris Lameter <[email protected]> Cc: Russell King <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Andrew Hunter <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: "Paul E . McKenney" <[email protected]> Cc: Paul Turner <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Ben Maurer <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Andy Lutomirski <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
-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)