Merge branch 'restart-cleanup' into restart

Conflicts: arch/arm/kernel/setup.c
2012-01-05 12:56:44 +00:00
parent 59136ef3c5 4c5f830c4c
commit 4045407fd7
1597 changed files with 20903 additions and 17484 deletions
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -385,6 +385,8 @@
 		CALL(sys_syncfs)
 		CALL(sys_sendmmsg)
 /* 375 */	CALL(sys_setns)
+		CALL(sys_process_vm_readv)
+		CALL(sys_process_vm_writev)
 #ifndef syscalls_counted
 .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
 #define syscalls_counted
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -497,7 +497,7 @@ ENDPROC(__und_usr)
 	.popsection
 	.pushsection __ex_table,"a"
 	.long	1b, 4b
-#if __LINUX_ARM_ARCH__ >= 7
+#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
 	.long	2b, 4b
 	.long	3b, 4b
 #endif
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -360,7 +360,7 @@ __secondary_data:
 *  r13 = *virtual* address to jump to upon completion
 */
 __enable_mmu:
-#ifdef CONFIG_ALIGNMENT_TRAP
+#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
 	orr	r0, r0, #CR_A
 #else
 	bic	r0, r0, #CR_A
--- a/arch/arm/kernel/kprobes-arm.c
+++ b/arch/arm/kernel/kprobes-arm.c
@@ -519,10 +519,12 @@ static const union decode_item arm_cccc_0000_____1001_table[] = {
 static const union decode_item arm_cccc_0001_____1001_table[] = {
 	/* Synchronization primitives					*/

+#if __LINUX_ARM_ARCH__ < 6
+	/* Deprecated on ARMv6 and may be UNDEFINED on v7		*/
 	/* SMP/SWPB		cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */
 	DECODE_EMULATEX	(0x0fb000f0, 0x01000090, emulate_rd12rn16rm0_rwflags_nopc,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
-
+#endif
 	/* LDREX/STREX{,D,B,H}	cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */
 	/* And unallocated instructions...				*/
 	DECODE_END
--- a/arch/arm/kernel/kprobes-test-arm.c
+++ b/arch/arm/kernel/kprobes-test-arm.c
@@ -427,18 +427,25 @@ void kprobe_arm_test_cases(void)

 	TEST_GROUP("Synchronization primitives")

-	/*
-	 * Use hard coded constants for SWP instructions to avoid warnings
-	 * about deprecated instructions.
-	 */
-	TEST_RP( ".word 0xe108e097 @ swp	lr, r",7,VAL2,", [r",8,0,"]")
-	TEST_R(  ".word 0x610d0091 @ swpvs	r0, r",1,VAL1,", [sp]")
-	TEST_RP( ".word 0xe10cd09e @ swp	sp, r",14,VAL2,", [r",12,13*4,"]")
+#if __LINUX_ARM_ARCH__ < 6
+	TEST_RP("swp	lr, r",7,VAL2,", [r",8,0,"]")
+	TEST_R( "swpvs	r0, r",1,VAL1,", [sp]")
+	TEST_RP("swp	sp, r",14,VAL2,", [r",12,13*4,"]")
+#else
+	TEST_UNSUPPORTED(".word 0xe108e097 @ swp	lr, r7, [r8]")
+	TEST_UNSUPPORTED(".word 0x610d0091 @ swpvs	r0, r1, [sp]")
+	TEST_UNSUPPORTED(".word 0xe10cd09e @ swp	sp, r14 [r12]")
+#endif
 	TEST_UNSUPPORTED(".word 0xe102f091 @ swp pc, r1, [r2]")
 	TEST_UNSUPPORTED(".word 0xe102009f @ swp r0, pc, [r2]")
 	TEST_UNSUPPORTED(".word 0xe10f0091 @ swp r0, r1, [pc]")
-	TEST_RP( ".word 0xe148e097 @ swpb	lr, r",7,VAL2,", [r",8,0,"]")
-	TEST_R(  ".word 0x614d0091 @ swpvsb	r0, r",1,VAL1,", [sp]")
+#if __LINUX_ARM_ARCH__ < 6
+	TEST_RP("swpb	lr, r",7,VAL2,", [r",8,0,"]")
+	TEST_R( "swpvsb	r0, r",1,VAL1,", [sp]")
+#else
+	TEST_UNSUPPORTED(".word 0xe148e097 @ swpb	lr, r7, [r8]")
+	TEST_UNSUPPORTED(".word 0x614d0091 @ swpvsb	r0, r1, [sp]")
+#endif
 	TEST_UNSUPPORTED(".word 0xe142f091 @ swpb pc, r1, [r2]")

 	TEST_UNSUPPORTED(".word	0xe1100090") /* Unallocated space */
@@ -550,7 +557,7 @@ void kprobe_arm_test_cases(void)
 	TEST_RPR(  "strccd	r",8, VAL2,", [r",13,0, ", r",12,48,"]")
 	TEST_RPR(  "strd	r",4, VAL1,", [r",2, 24,", r",3, 48,"]!")
 	TEST_RPR(  "strcsd	r",12,VAL2,", [r",11,48,", -r",10,24,"]!")
-	TEST_RPR(  "strd	r",2, VAL1,", [r",3, 24,"], r",4,48,"")
+	TEST_RPR(  "strd	r",2, VAL1,", [r",5, 24,"], r",4,48,"")
 	TEST_RPR(  "strd	r",10,VAL2,", [r",9, 48,"], -r",7,24,"")
 	TEST_UNSUPPORTED(".word 0xe1afc0fa	@ strd r12, [pc, r10]!")

--- a/arch/arm/kernel/kprobes-test-thumb.c
+++ b/arch/arm/kernel/kprobes-test-thumb.c
@@ -222,8 +222,8 @@ void kprobe_thumb16_test_cases(void)
 DONT_TEST_IN_ITBLOCK(
 	TEST_BF_R(  "cbnz	r",0,0, ", 2f")
 	TEST_BF_R(  "cbz	r",2,-1,", 2f")
-	TEST_BF_RX( "cbnz	r",4,1, ", 2f",0x20)
-	TEST_BF_RX( "cbz	r",7,0, ", 2f",0x40)
+	TEST_BF_RX( "cbnz	r",4,1, ", 2f", SPACE_0x20)
+	TEST_BF_RX( "cbz	r",7,0, ", 2f", SPACE_0x40)
 )
 	TEST_R("sxth	r0, r",7, HH1,"")
 	TEST_R("sxth	r7, r",0, HH2,"")
@@ -246,7 +246,7 @@ DONT_TEST_IN_ITBLOCK(
 	TESTCASE_START(code)		\
 	TEST_ARG_PTR(13, offset)	\
 	TEST_ARG_END("")		\
-	TEST_BRANCH_F(code,0)		\
+	TEST_BRANCH_F(code)		\
 	TESTCASE_END

 	TEST("push	{r0}")
@@ -319,8 +319,8 @@ CONDITION_INSTRUCTIONS(8,

 	TEST_BF(  "b	2f")
 	TEST_BB(  "b	2b")
-	TEST_BF_X("b	2f", 0x400)
-	TEST_BB_X("b	2b", 0x400)
+	TEST_BF_X("b	2f", SPACE_0x400)
+	TEST_BB_X("b	2b", SPACE_0x400)

 	TEST_GROUP("Testing instructions in IT blocks")

@@ -746,7 +746,7 @@ CONDITION_INSTRUCTIONS(22,
 	TEST_BB("bne.w	2b")
 	TEST_BF("bgt.w	2f")
 	TEST_BB("blt.w	2b")
-	TEST_BF_X("bpl.w	2f",0x1000)
+	TEST_BF_X("bpl.w	2f", SPACE_0x1000)
 )

 	TEST_UNSUPPORTED("msr	cpsr, r0")
@@ -786,11 +786,11 @@ CONDITION_INSTRUCTIONS(22,

 	TEST_BF(  "b.w	2f")
 	TEST_BB(  "b.w	2b")
-	TEST_BF_X("b.w	2f", 0x1000)
+	TEST_BF_X("b.w	2f", SPACE_0x1000)

 	TEST_BF(  "bl.w	2f")
 	TEST_BB(  "bl.w	2b")
-	TEST_BB_X("bl.w	2b", 0x1000)
+	TEST_BB_X("bl.w	2b", SPACE_0x1000)

 	TEST_X(	"blx	__dummy_arm_subroutine",
 		".arm				\n\t"
--- a/arch/arm/kernel/kprobes-test.h
+++ b/arch/arm/kernel/kprobes-test.h
@@ -149,23 +149,31 @@ struct test_arg_end {
 	"1:	"instruction"				\n\t"	\
 	"	nop					\n\t"

-#define TEST_BRANCH_F(instruction, xtra_dist)			\
+#define TEST_BRANCH_F(instruction)				\
 	TEST_INSTRUCTION(instruction)				\
-	".if "#xtra_dist"				\n\t"	\
-	"	b	99f				\n\t"	\
-	".space "#xtra_dist"				\n\t"	\
-	".endif						\n\t"	\
 	"	b	99f				\n\t"	\
 	"2:	nop					\n\t"

-#define TEST_BRANCH_B(instruction, xtra_dist)			\
+#define TEST_BRANCH_B(instruction)				\
 	"	b	50f				\n\t"	\
 	"	b	99f				\n\t"	\
 	"2:	nop					\n\t"	\
 	"	b	99f				\n\t"	\
-	".if "#xtra_dist"				\n\t"	\
-	".space "#xtra_dist"				\n\t"	\
-	".endif						\n\t"	\
+	TEST_INSTRUCTION(instruction)
+
+#define TEST_BRANCH_FX(instruction, codex)			\
+	TEST_INSTRUCTION(instruction)				\
+	"	b	99f				\n\t"	\
+	codex"						\n\t"	\
+	"	b	99f				\n\t"	\
+	"2:	nop					\n\t"
+
+#define TEST_BRANCH_BX(instruction, codex)			\
+	"	b	50f				\n\t"	\
+	"	b	99f				\n\t"	\
+	"2:	nop					\n\t"	\
+	"	b	99f				\n\t"	\
+	codex"						\n\t"	\
 	TEST_INSTRUCTION(instruction)

 #define TESTCASE_END						\
@@ -301,47 +309,60 @@ struct test_arg_end {
 	TESTCASE_START(code1 #reg1 code2)	\
 	TEST_ARG_PTR(reg1, val1)		\
 	TEST_ARG_END("")			\
-	TEST_BRANCH_F(code1 #reg1 code2, 0)	\
+	TEST_BRANCH_F(code1 #reg1 code2)	\
 	TESTCASE_END

-#define TEST_BF_X(code, xtra_dist)		\
+#define TEST_BF(code)				\
 	TESTCASE_START(code)			\
 	TEST_ARG_END("")			\
-	TEST_BRANCH_F(code, xtra_dist)		\
+	TEST_BRANCH_F(code)			\
 	TESTCASE_END

-#define TEST_BB_X(code, xtra_dist)		\
+#define TEST_BB(code)				\
 	TESTCASE_START(code)			\
 	TEST_ARG_END("")			\
-	TEST_BRANCH_B(code, xtra_dist)		\
+	TEST_BRANCH_B(code)			\
 	TESTCASE_END

-#define TEST_BF_RX(code1, reg, val, code2, xtra_dist)	\
-	TESTCASE_START(code1 #reg code2)		\
-	TEST_ARG_REG(reg, val)				\
-	TEST_ARG_END("")				\
-	TEST_BRANCH_F(code1 #reg code2, xtra_dist)	\
+#define TEST_BF_R(code1, reg, val, code2)	\
+	TESTCASE_START(code1 #reg code2)	\
+	TEST_ARG_REG(reg, val)			\
+	TEST_ARG_END("")			\
+	TEST_BRANCH_F(code1 #reg code2)		\
 	TESTCASE_END

-#define TEST_BB_RX(code1, reg, val, code2, xtra_dist)	\
-	TESTCASE_START(code1 #reg code2)		\
-	TEST_ARG_REG(reg, val)				\
-	TEST_ARG_END("")				\
-	TEST_BRANCH_B(code1 #reg code2, xtra_dist)	\
+#define TEST_BB_R(code1, reg, val, code2)	\
+	TESTCASE_START(code1 #reg code2)	\
+	TEST_ARG_REG(reg, val)			\
+	TEST_ARG_END("")			\
+	TEST_BRANCH_B(code1 #reg code2)		\
 	TESTCASE_END

-#define TEST_BF(code)	TEST_BF_X(code, 0)
-#define TEST_BB(code)	TEST_BB_X(code, 0)
-
-#define TEST_BF_R(code1, reg, val, code2) TEST_BF_RX(code1, reg, val, code2, 0)
-#define TEST_BB_R(code1, reg, val, code2) TEST_BB_RX(code1, reg, val, code2, 0)
-
 #define TEST_BF_RR(code1, reg1, val1, code2, reg2, val2, code3)	\
 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)		\
 	TEST_ARG_REG(reg1, val1)				\
 	TEST_ARG_REG(reg2, val2)				\
 	TEST_ARG_END("")					\
-	TEST_BRANCH_F(code1 #reg1 code2 #reg2 code3, 0)		\
+	TEST_BRANCH_F(code1 #reg1 code2 #reg2 code3)		\
+	TESTCASE_END
+
+#define TEST_BF_X(code, codex)			\
+	TESTCASE_START(code)			\
+	TEST_ARG_END("")			\
+	TEST_BRANCH_FX(code, codex)		\
+	TESTCASE_END
+
+#define TEST_BB_X(code, codex)			\
+	TESTCASE_START(code)			\
+	TEST_ARG_END("")			\
+	TEST_BRANCH_BX(code, codex)		\
+	TESTCASE_END
+
+#define TEST_BF_RX(code1, reg, val, code2, codex)	\
+	TESTCASE_START(code1 #reg code2)		\
+	TEST_ARG_REG(reg, val)				\
+	TEST_ARG_END("")				\
+	TEST_BRANCH_FX(code1 #reg code2, codex)		\
 	TESTCASE_END

 #define TEST_X(code, codex)			\
@@ -372,6 +393,25 @@ struct test_arg_end {
 	TESTCASE_END


+/*
+ * Macros for defining space directives spread over multiple lines.
+ * These are required so the compiler guesses better the length of inline asm
+ * code and will spill the literal pool early enough to avoid generating PC
+ * relative loads with out of range offsets.
+ */
+#define TWICE(x)	x x
+#define SPACE_0x8	TWICE(".space 4\n\t")
+#define SPACE_0x10	TWICE(SPACE_0x8)
+#define SPACE_0x20	TWICE(SPACE_0x10)
+#define SPACE_0x40	TWICE(SPACE_0x20)
+#define SPACE_0x80	TWICE(SPACE_0x40)
+#define SPACE_0x100	TWICE(SPACE_0x80)
+#define SPACE_0x200	TWICE(SPACE_0x100)
+#define SPACE_0x400	TWICE(SPACE_0x200)
+#define SPACE_0x800	TWICE(SPACE_0x400)
+#define SPACE_0x1000	TWICE(SPACE_0x800)
+
+
 /* Various values used in test cases... */
 #define N(val)	(val ^ 0xffffffff)
 #define VAL1	0x12345678
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -32,24 +32,6 @@ static atomic_t waiting_for_crash_ipi;

 int machine_kexec_prepare(struct kimage *image)
 {
-	unsigned long page_list;
-	void *reboot_code_buffer;
-	page_list = image->head & PAGE_MASK;
-
-	reboot_code_buffer = page_address(image->control_code_page);
-
-	/* Prepare parameters for reboot_code_buffer*/
-	kexec_start_address = image->start;
-	kexec_indirection_page = page_list;
-	kexec_mach_type = machine_arch_type;
-	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
-
-	/* copy our kernel relocation code to the control code page */
-	memcpy(reboot_code_buffer,
-	       relocate_new_kernel, relocate_new_kernel_size);
-
-	flush_icache_range((unsigned long) reboot_code_buffer,
-			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 	return 0;
 }

@@ -100,14 +82,31 @@ void (*kexec_reinit)(void);

 void machine_kexec(struct kimage *image)
 {
+	unsigned long page_list;
 	unsigned long reboot_code_buffer_phys;
 	void *reboot_code_buffer;

+
+	page_list = image->head & PAGE_MASK;
+
 	/* we need both effective and real address here */
 	reboot_code_buffer_phys =
 	    page_to_pfn(image->control_code_page) << PAGE_SHIFT;
 	reboot_code_buffer = page_address(image->control_code_page);

+	/* Prepare parameters for reboot_code_buffer*/
+	kexec_start_address = image->start;
+	kexec_indirection_page = page_list;
+	kexec_mach_type = machine_arch_type;
+	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
+
+	/* copy our kernel relocation code to the control code page */
+	memcpy(reboot_code_buffer,
+	       relocate_new_kernel, relocate_new_kernel_size);
+
+
+	flush_icache_range((unsigned long) reboot_code_buffer,
+			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 	printk(KERN_INFO "Bye!\n");

 	if (kexec_reinit)
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -343,19 +343,25 @@ validate_group(struct perf_event *event)
 {
 	struct perf_event *sibling, *leader = event->group_leader;
 	struct pmu_hw_events fake_pmu;
+	DECLARE_BITMAP(fake_used_mask, ARMPMU_MAX_HWEVENTS);

-	memset(&fake_pmu, 0, sizeof(fake_pmu));
+	/*
+	 * Initialise the fake PMU. We only need to populate the
+	 * used_mask for the purposes of validation.
+	 */
+	memset(fake_used_mask, 0, sizeof(fake_used_mask));
+	fake_pmu.used_mask = fake_used_mask;

 	if (!validate_event(&fake_pmu, leader))
-		return -ENOSPC;
+		return -EINVAL;

 	list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
 		if (!validate_event(&fake_pmu, sibling))
-			return -ENOSPC;
+			return -EINVAL;
 	}

 	if (!validate_event(&fake_pmu, event))
-		return -ENOSPC;
+		return -EINVAL;

 	return 0;
 }
@@ -396,6 +402,9 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu)
 	int i, err, irq, irqs;
 	struct platform_device *pmu_device = armpmu->plat_device;

+	if (!pmu_device)
+		return -ENODEV;
+
 	err = reserve_pmu(armpmu->type);
 	if (err) {
 		pr_warning("unable to reserve pmu\n");
@@ -631,6 +640,9 @@ static struct platform_device_id armpmu_plat_device_ids[] = {

 static int __devinit armpmu_device_probe(struct platform_device *pdev)
 {
+	if (!cpu_pmu)
+		return -ENODEV;
+
 	cpu_pmu->plat_device = pdev;
 	return 0;
 }
--- a/arch/arm/kernel/pmu.c
+++ b/arch/arm/kernel/pmu.c
@@ -33,3 +33,4 @@ release_pmu(enum arm_pmu_type type)
 {
 	clear_bit_unlock(type, pmu_lock);
 }
+EXPORT_SYMBOL_GPL(release_pmu);
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -191,6 +191,9 @@ void cpu_idle(void)
 #endif

 			local_irq_disable();
+#ifdef CONFIG_PL310_ERRATA_769419
+			wmb();
+#endif
 			if (hlt_counter) {
 				local_irq_enable();
 				cpu_relax();
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -461,8 +461,10 @@ static void __init setup_processor(void)
 	       cpu_name, read_cpuid_id(), read_cpuid_id() & 15,
 	       proc_arch[cpu_architecture()], cr_alignment);

-	sprintf(init_utsname()->machine, "%s%c", list->arch_name, ENDIANNESS);
-	sprintf(elf_platform, "%s%c", list->elf_name, ENDIANNESS);
+	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
+		 list->arch_name, ENDIANNESS);
+	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
+		 list->elf_name, ENDIANNESS);
 	elf_hwcap = list->elf_hwcap;
 #ifndef CONFIG_ARM_THUMB
 	elf_hwcap &= ~HWCAP_THUMB;
@@ -893,8 +895,6 @@ void __init setup_arch(char **cmdline_p)
 {
 	struct machine_desc *mdesc;

-	unwind_init();
-
 	setup_processor();
 	mdesc = setup_machine_fdt(__atags_pointer);
 	if (!mdesc)
@@ -902,6 +902,12 @@ void __init setup_arch(char **cmdline_p)
 	machine_desc = mdesc;
 	machine_name = mdesc->name;

+#ifdef CONFIG_ZONE_DMA
+	if (mdesc->dma_zone_size) {
+		extern unsigned long arm_dma_zone_size;
+		arm_dma_zone_size = mdesc->dma_zone_size;
+	}
+#endif
 	if (mdesc->restart_mode)
 		reboot_setup(&mdesc->restart_mode);

@@ -935,12 +941,6 @@ void __init setup_arch(char **cmdline_p)

 	tcm_init();

-#ifdef CONFIG_ZONE_DMA
-	if (mdesc->dma_zone_size) {
-		extern unsigned long arm_dma_zone_size;
-		arm_dma_zone_size = mdesc->dma_zone_size;
-	}
-#endif
 #ifdef CONFIG_MULTI_IRQ_HANDLER
 	handle_arch_irq = mdesc->handle_irq;
 #endif
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -43,7 +43,7 @@

 struct cputopo_arm cpu_topology[NR_CPUS];

-const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
+const struct cpumask *cpu_coregroup_mask(int cpu)
 {
 	return &cpu_topology[cpu].core_sibling;
 }
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -67,7 +67,7 @@ EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2);

 struct unwind_ctrl_block {
 	unsigned long vrs[16];		/* virtual register set */
-	unsigned long *insn;		/* pointer to the current instructions word */
+	const unsigned long *insn;	/* pointer to the current instructions word */
 	int entries;			/* number of entries left to interpret */
 	int byte;			/* current byte number in the instructions word */
 };
@@ -83,8 +83,9 @@ enum regs {
 	PC = 15
 };

-extern struct unwind_idx __start_unwind_idx[];
-extern struct unwind_idx __stop_unwind_idx[];
+extern const struct unwind_idx __start_unwind_idx[];
+static const struct unwind_idx *__origin_unwind_idx;
+extern const struct unwind_idx __stop_unwind_idx[];

 static DEFINE_SPINLOCK(unwind_lock);
 static LIST_HEAD(unwind_tables);
@@ -98,45 +99,99 @@ static LIST_HEAD(unwind_tables);
 })

 /*
- * Binary search in the unwind index. The entries entries are
+ * Binary search in the unwind index. The entries are
 * guaranteed to be sorted in ascending order by the linker.
+ *
+ * start = first entry
+ * origin = first entry with positive offset (or stop if there is no such entry)
+ * stop - 1 = last entry
 */
-static struct unwind_idx *search_index(unsigned long addr,
-				       struct unwind_idx *first,
-				       struct unwind_idx *last)
+static const struct unwind_idx *search_index(unsigned long addr,
+				       const struct unwind_idx *start,
+				       const struct unwind_idx *origin,
+				       const struct unwind_idx *stop)
 {
-	pr_debug("%s(%08lx, %p, %p)\n", __func__, addr, first, last);
+	unsigned long addr_prel31;

-	if (addr < first->addr) {
-		pr_warning("unwind: Unknown symbol address %08lx\n", addr);
-		return NULL;
-	} else if (addr >= last->addr)
-		return last;
+	pr_debug("%s(%08lx, %p, %p, %p)\n",
+			__func__, addr, start, origin, stop);

-	while (first < last - 1) {
-		struct unwind_idx *mid = first + ((last - first + 1) >> 1);
+	/*
+	 * only search in the section with the matching sign. This way the
+	 * prel31 numbers can be compared as unsigned longs.
+	 */
+	if (addr < (unsigned long)start)
+		/* negative offsets: [start; origin) */
+		stop = origin;
+	else
+		/* positive offsets: [origin; stop) */
+		start = origin;

-		if (addr < mid->addr)
-			last = mid;
-		else
-			first = mid;
+	/* prel31 for address relavive to start */
+	addr_prel31 = (addr - (unsigned long)start) & 0x7fffffff;
+
+	while (start < stop - 1) {
+		const struct unwind_idx *mid = start + ((stop - start) >> 1);
+
+		/*
+		 * As addr_prel31 is relative to start an offset is needed to
+		 * make it relative to mid.
+		 */
+		if (addr_prel31 - ((unsigned long)mid - (unsigned long)start) <
+				mid->addr_offset)
+			stop = mid;
+		else {
+			/* keep addr_prel31 relative to start */
+			addr_prel31 -= ((unsigned long)mid -
+					(unsigned long)start);
+			start = mid;
+		}
 	}

-	return first;
+	if (likely(start->addr_offset <= addr_prel31))
+		return start;
+	else {
+		pr_warning("unwind: Unknown symbol address %08lx\n", addr);
+		return NULL;
+	}
 }

-static struct unwind_idx *unwind_find_idx(unsigned long addr)
+static const struct unwind_idx *unwind_find_origin(
+		const struct unwind_idx *start, const struct unwind_idx *stop)
 {
-	struct unwind_idx *idx = NULL;
+	pr_debug("%s(%p, %p)\n", __func__, start, stop);
+	while (start < stop) {
+		const struct unwind_idx *mid = start + ((stop - start) >> 1);
+
+		if (mid->addr_offset >= 0x40000000)
+			/* negative offset */
+			start = mid + 1;
+		else
+			/* positive offset */
+			stop = mid;
+	}
+	pr_debug("%s -> %p\n", __func__, stop);
+	return stop;
+}
+
+static const struct unwind_idx *unwind_find_idx(unsigned long addr)
+{
+	const struct unwind_idx *idx = NULL;
 	unsigned long flags;

 	pr_debug("%s(%08lx)\n", __func__, addr);

-	if (core_kernel_text(addr))
+	if (core_kernel_text(addr)) {
+		if (unlikely(!__origin_unwind_idx))
+			__origin_unwind_idx =
+				unwind_find_origin(__start_unwind_idx,
+						__stop_unwind_idx);
+
 		/* main unwind table */
 		idx = search_index(addr, __start_unwind_idx,
-				   __stop_unwind_idx - 1);
-	else {
+				   __origin_unwind_idx,
+				   __stop_unwind_idx);
+	} else {
 		/* module unwind tables */
 		struct unwind_table *table;

@@ -145,7 +200,8 @@ static struct unwind_idx *unwind_find_idx(unsigned long addr)
 			if (addr >= table->begin_addr &&
 			    addr < table->end_addr) {
 				idx = search_index(addr, table->start,
-						   table->stop - 1);
+						   table->origin,
+						   table->stop);
 				/* Move-to-front to exploit common traces */
 				list_move(&table->list, &unwind_tables);
 				break;
@@ -274,7 +330,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 int unwind_frame(struct stackframe *frame)
 {
 	unsigned long high, low;
-	struct unwind_idx *idx;
+	const struct unwind_idx *idx;
 	struct unwind_ctrl_block ctrl;

 	/* only go to a higher address on the stack */
@@ -399,7 +455,6 @@ struct unwind_table *unwind_table_add(unsigned long start, unsigned long size,
 				      unsigned long text_size)
 {
 	unsigned long flags;
-	struct unwind_idx *idx;
 	struct unwind_table *tab = kmalloc(sizeof(*tab), GFP_KERNEL);

 	pr_debug("%s(%08lx, %08lx, %08lx, %08lx)\n", __func__, start, size,
@@ -408,15 +463,12 @@ struct unwind_table *unwind_table_add(unsigned long start, unsigned long size,
 	if (!tab)
 		return tab;

-	tab->start = (struct unwind_idx *)start;
-	tab->stop = (struct unwind_idx *)(start + size);
+	tab->start = (const struct unwind_idx *)start;
+	tab->stop = (const struct unwind_idx *)(start + size);
+	tab->origin = unwind_find_origin(tab->start, tab->stop);
 	tab->begin_addr = text_addr;
 	tab->end_addr = text_addr + text_size;

-	/* Convert the symbol addresses to absolute values */
-	for (idx = tab->start; idx < tab->stop; idx++)
-		idx->addr = prel31_to_addr(&idx->addr);
-
 	spin_lock_irqsave(&unwind_lock, flags);
 	list_add_tail(&tab->list, &unwind_tables);
 	spin_unlock_irqrestore(&unwind_lock, flags);
@@ -437,16 +489,3 @@ void unwind_table_del(struct unwind_table *tab)

 	kfree(tab);
 }
-
-int __init unwind_init(void)
-{
-	struct unwind_idx *idx;
-
-	/* Convert the symbol addresses to absolute values */
-	for (idx = __start_unwind_idx; idx < __stop_unwind_idx; idx++)
-		idx->addr = prel31_to_addr(&idx->addr);
-
-	pr_debug("unwind: ARM stack unwinding initialised\n");
-
-	return 0;
-}