[1/4] arm64: insn: Do not disable irqs during patching

Commit Message

Matthias Brugger Aug. 4, 2016, 9:15 a.m. UTC

From: Robert Richter <[e-mail]>

__aarch64_insn_write() is always called with interrupts enabled. Thus,
there is no need to use an irqsave variant for the spin lock.

This change should also address the fix of:

commit abffa6f3b157 ("arm64: convert patch_lock to raw lock")

We need to enable interrupts to allow cpu sync for code patching
using smp_call_function*().

Signed-off-by: Robert Richter <[e-mail]>
Signed-off-by: Matthias Brugger <[e-mail]>
---
 arch/arm64/kernel/insn.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 63f9432..138bd8a 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -86,7 +86,7 @@  bool aarch64_insn_is_branch_imm(u32 insn)
 		aarch64_insn_is_bcond(insn));
 }
 
-static DEFINE_RAW_SPINLOCK(patch_lock);
+static DEFINE_SPINLOCK(patch_lock);
 
 static void __kprobes *patch_map(void *addr, int fixmap)
 {
@@ -129,16 +129,15 @@  int __kprobes aarch64_insn_read(void *addr, u32 *insnp)
 static int __kprobes __aarch64_insn_write(void *addr, u32 insn)
 {
 	void *waddr = addr;
-	unsigned long flags = 0;
 	int ret;
 
-	raw_spin_lock_irqsave(&patch_lock, flags);
+	spin_lock(&patch_lock);
 	waddr = patch_map(addr, FIX_TEXT_POKE0);
 
 	ret = probe_kernel_write(waddr, &insn, AARCH64_INSN_SIZE);
 
 	patch_unmap(FIX_TEXT_POKE0);
-	raw_spin_unlock_irqrestore(&patch_lock, flags);
+	spin_unlock(&patch_lock);
 
 	return ret;
 }