Merge branch 'x86/urgent' into x86/asm, to pick up fixes

[cascardo/linux.git] / arch / x86 / entry / entry_64.S

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 8956eae..f6b40e5 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -288,11 +288,15 @@ return_from_SYSCALL_64:
        jne     opportunistic_sysret_failed
 
        /*
-        * SYSRET can't restore RF.  SYSRET can restore TF, but unlike IRET,
-        * restoring TF results in a trap from userspace immediately after
-        * SYSRET.  This would cause an infinite loop whenever #DB happens
-        * with register state that satisfies the opportunistic SYSRET
-        * conditions.  For example, single-stepping this user code:
+        * SYSCALL clears RF when it saves RFLAGS in R11 and SYSRET cannot
+        * restore RF properly. If the slowpath sets it for whatever reason, we
+        * need to restore it correctly.
+        *
+        * SYSRET can restore TF, but unlike IRET, restoring TF results in a
+        * trap from userspace immediately after SYSRET.  This would cause an
+        * infinite loop whenever #DB happens with register state that satisfies
+        * the opportunistic SYSRET conditions.  For example, single-stepping
+        * this user code:
         *
         *           movq       $stuck_here, %rcx
         *           pushfq
@@ -600,9 +604,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
 .endm
 #endif
 
+/* Make sure APIC interrupt handlers end up in the irqentry section: */
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+# define PUSH_SECTION_IRQENTRY .pushsection .irqentry.text, "ax"
+# define POP_SECTION_IRQENTRY  .popsection
+#else
+# define PUSH_SECTION_IRQENTRY
+# define POP_SECTION_IRQENTRY
+#endif
+
 .macro apicinterrupt num sym do_sym
+PUSH_SECTION_IRQENTRY
 apicinterrupt3 \num \sym \do_sym
 trace_apicinterrupt \num \sym
+POP_SECTION_IRQENTRY
 .endm
 
 #ifdef CONFIG_SMP