Merge branch 'master' into for-linus

4 files changed, 43 insertions, 10 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 3d727a8a23bc..0a2ba51cf35d 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -272,7 +272,15 @@ __und_svc:
         @
         @  r0 - instruction
         @
+#ifndef CONFIG_THUMB2_KERNEL
         ldr     r0, [r2, #-4]
+#else
+        ldrh    r0, [r2, #-2]                   @ Thumb instruction at LR - 2
+        and     r9, r0, #0xf800
+        cmp     r9, #0xe800                     @ 32-bit instruction if xx >= 0
+        ldrhhs  r9, [r2]                        @ bottom 16 bits
+        orrhs   r0, r9, r0, lsl #16
+#endif
         adr     r9, BSYM(1f)
         bl      call_fpe
 
@@ -678,7 +686,9 @@ ENTRY(fp_enter)
         .word   no_fp
         .previous
 
-no_fp:  mov     pc, lr
+ENTRY(no_fp)
+        mov     pc, lr
+ENDPROC(no_fp)
 
 __und_usr_unknown:
         enable_irq
@@ -734,13 +744,6 @@ ENTRY(__switch_to)
 #ifdef CONFIG_MMU
         ldr     r6, [r2, #TI_CPU_DOMAIN]
 #endif
-#if __LINUX_ARM_ARCH__ >= 6
-#ifdef CONFIG_CPU_32v6K
-        clrex
-#else
-        strex   r5, r4, [ip]                    @ Clear exclusive monitor
-#endif
-#endif
 #if defined(CONFIG_HAS_TLS_REG)
         mcr     p15, 0, r3, c13, c0, 3          @ set TLS register
 #elif !defined(CONFIG_TLS_REG_EMUL)
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index a4eaf4f920c5..e17e3c30d957 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -76,13 +76,25 @@
 #ifndef CONFIG_THUMB2_KERNEL
         .macro  svc_exit, rpsr
         msr     spsr_cxsf, \rpsr
+#if defined(CONFIG_CPU_32v6K)
+        clrex                                   @ clear the exclusive monitor
         ldmia   sp, {r0 - pc}^                  @ load r0 - pc, cpsr
+#elif defined (CONFIG_CPU_V6)
+        ldr     r0, [sp]
+        strex   r1, r2, [sp]                    @ clear the exclusive monitor
+        ldmib   sp, {r1 - pc}^                  @ load r1 - pc, cpsr
+#endif
         .endm
 
         .macro  restore_user_regs, fast = 0, offset = 0
         ldr     r1, [sp, #\offset + S_PSR]      @ get calling cpsr
         ldr     lr, [sp, #\offset + S_PC]!      @ get pc
         msr     spsr_cxsf, r1                   @ save in spsr_svc
+#if defined(CONFIG_CPU_32v6K)
+        clrex                                   @ clear the exclusive monitor
+#elif defined (CONFIG_CPU_V6)
+        strex   r1, r2, [sp]                    @ clear the exclusive monitor
+#endif
         .if     \fast
         ldmdb   sp, {r1 - lr}^                  @ get calling r1 - lr
         .else
@@ -98,6 +110,7 @@
         .endm
 #else   /* CONFIG_THUMB2_KERNEL */
         .macro  svc_exit, rpsr
+        clrex                                   @ clear the exclusive monitor
         ldr     r0, [sp, #S_SP]                 @ top of the stack
         ldr     r1, [sp, #S_PC]                 @ return address
         tst     r0, #4                          @ orig stack 8-byte aligned?
@@ -110,6 +123,7 @@
         .endm
 
         .macro  restore_user_regs, fast = 0, offset = 0
+        clrex                                   @ clear the exclusive monitor
         mov     r2, sp
         load_user_sp_lr r2, r3, \offset + S_SP  @ calling sp, lr
         ldr     r1, [sp, #\offset + S_PSR]      @ get calling cpsr
diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c
index f692efddd449..60c62c377fa9 100644
--- a/arch/arm/kernel/kprobes.c
+++ b/arch/arm/kernel/kprobes.c
@@ -22,6 +22,7 @@
 #include <linux/kernel.h>
 #include <linux/kprobes.h>
 #include <linux/module.h>
+#include <linux/stop_machine.h>
 #include <linux/stringify.h>
 #include <asm/traps.h>
 #include <asm/cacheflush.h>
@@ -83,10 +84,24 @@ void __kprobes arch_arm_kprobe(struct kprobe *p)
         flush_insns(p->addr, 1);
 }
 
+/*
+ * The actual disarming is done here on each CPU and synchronized using
+ * stop_machine. This synchronization is necessary on SMP to avoid removing
+ * a probe between the moment the 'Undefined Instruction' exception is raised
+ * and the moment the exception handler reads the faulting instruction from
+ * memory.
+ */
+int __kprobes __arch_disarm_kprobe(void *p)
+{
+        struct kprobe *kp = p;
+        *kp->addr = kp->opcode;
+        flush_insns(kp->addr, 1);
+        return 0;
+}
+
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
 {
-        *p->addr = p->opcode;
-        flush_insns(p->addr, 1);
+        stop_machine(__arch_disarm_kprobe, p, &cpu_online_map);
 }
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 39d3ffb9ff2b..aecf87dfbaec 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -83,6 +83,7 @@ SECTIONS
                 EXIT_TEXT
                 EXIT_DATA
                 *(.exitcall.exit)
+                *(.discard)
                 *(.ARM.exidx.exit.text)
                 *(.ARM.extab.exit.text)
 #ifndef CONFIG_HOTPLUG_CPU