Merge branch 'oprofile/urgent' into HEAD (a406ab6d) · Commits · e / devices / android_kernel_fairphone_FP3

arch/x86/oprofile/backtrace.c

+47 −9

Original line number	Diff line number	Diff line
		@@ -11,10 +11,12 @@
		#include <linux/oprofile.h>
		#include <linux/sched.h>
		#include <linux/mm.h>
		#include <linux/compat.h>
		#include <linux/highmem.h>

		#include <asm/ptrace.h>
		#include <asm/uaccess.h>
		#include <asm/stacktrace.h>
		#include <linux/compat.h>

		static int backtrace_stack(void data, char name)
		{
		@@ -36,17 +38,53 @@ static struct stacktrace_ops backtrace_ops = {
		.walk_stack = print_context_stack,
		};

		/* from arch/x86/kernel/cpu/perf_event.c: */

		/*
		* best effort, GUP based copy_from_user() that assumes IRQ or NMI context
		*/
		static unsigned long
		copy_from_user_nmi(void to, const void __user from, unsigned long n)
		{
		unsigned long offset, addr = (unsigned long)from;
		unsigned long size, len = 0;
		struct page *page;
		void *map;
		int ret;

		do {
		ret = __get_user_pages_fast(addr, 1, 0, &page);
		if (!ret)
		break;

		offset = addr & (PAGE_SIZE - 1);
		size = min(PAGE_SIZE - offset, n - len);

		map = kmap_atomic(page);
		memcpy(to, map+offset, size);
		kunmap_atomic(map);
		put_page(page);

		len += size;
		to += size;
		addr += size;

		} while (len < n);

		return len;
		}

		#ifdef CONFIG_COMPAT
		static struct stack_frame_ia32 *
		dump_user_backtrace_32(struct stack_frame_ia32 *head)
		{
		/* Also check accessibility of one struct frame_head beyond: */
		struct stack_frame_ia32 bufhead[2];
		struct stack_frame_ia32 *fp;
		unsigned long bytes;

		/* Also check accessibility of one struct frame_head beyond */
		if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
		return NULL;
		if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
		bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
		if (bytes != sizeof(bufhead))
		return NULL;

		fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
		@@ -87,12 +125,12 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)

		static struct stack_frame dump_user_backtrace(struct stack_frame head)
		{
		/* Also check accessibility of one struct frame_head beyond: */
		struct stack_frame bufhead[2];
		unsigned long bytes;

		/* Also check accessibility of one struct stack_frame beyond */
		if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
		return NULL;
		if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
		bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
		if (bytes != sizeof(bufhead))
		return NULL;

		oprofile_add_trace(bufhead[0].return_address);

arch/x86/oprofile/nmi_int.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -112,8 +112,10 @@ static void nmi_cpu_start(void *dummy)
		static int nmi_start(void)
		{
		get_online_cpus();
		on_each_cpu(nmi_cpu_start, NULL, 1);
		ctr_running = 1;
		/* make ctr_running visible to the nmi handler: */
		smp_mb();
		on_each_cpu(nmi_cpu_start, NULL, 1);
		put_online_cpus();
		return 0;
		}
		@@ -504,15 +506,18 @@ static int nmi_setup(void)

		nmi_enabled = 0;
		ctr_running = 0;
		barrier();
		/* make variables visible to the nmi handler: */
		smp_mb();
		err = register_die_notifier(&profile_exceptions_nb);
		if (err)
		goto fail;

		get_online_cpus();
		register_cpu_notifier(&oprofile_cpu_nb);
		on_each_cpu(nmi_cpu_setup, NULL, 1);
		nmi_enabled = 1;
		/* make nmi_enabled visible to the nmi handler: */
		smp_mb();
		on_each_cpu(nmi_cpu_setup, NULL, 1);
		put_online_cpus();

		return 0;
		@@ -531,7 +536,8 @@ static void nmi_shutdown(void)
		nmi_enabled = 0;
		ctr_running = 0;
		put_online_cpus();
		barrier();
		/* make variables visible to the nmi handler: */
		smp_mb();
		unregister_die_notifier(&profile_exceptions_nb);
		msrs = &get_cpu_var(cpu_msrs);
		model->shutdown(msrs);