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authorRussell King <rmk+kernel@arm.linux.org.uk>2009-09-22 20:54:53 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-09-22 21:01:40 +0100
commitae19ffbadc1b2100285a5b5b3d0a4e0a11390904 (patch)
tree3c2086ab67398a019089a47ca3f362a4bc6db74f /arch/arm/kernel
parent34e84f39a27d059a3e6ec6e8b94aafa702e6f220 (diff)
parent9173a8ef24a6b1b8031507b35b8ffe5f85a87692 (diff)
Merge branch 'master' into for-linus
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/entry-armv.S19
-rw-r--r--arch/arm/kernel/entry-header.S14
-rw-r--r--arch/arm/kernel/kprobes.c19
-rw-r--r--arch/arm/kernel/vmlinux.lds.S1
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