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Commit a0baf043 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
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perf/arch/x86: Implement hw_breakpoint_arch_parse() 



Migrate to the new API in order to remove arch_validate_hwbkpt_settings()
that clumsily mixes up architecture validation and commit.

Original-patch-by: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joel Fernandes <joel.opensrc@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/1529981939-8231-4-git-send-email-frederic@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8e983ff9

arch/x86/include/asm/hw_breakpoint.h

+5 −1
Original line number Diff line number Diff line
@@ -49,11 +49,15 @@ static inline int hw_breakpoint_slots(int type) 
	return HBP_NUM;

}



struct perf_event_attr;

struct perf_event;

struct pmu;



extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);

extern int arch_validate_hwbkpt_settings(struct perf_event *bp);

extern int hw_breakpoint_arch_parse(struct perf_event *bp,

				    const struct perf_event_attr *attr,

				    struct arch_hw_breakpoint *hw);

#define hw_breakpoint_arch_parse hw_breakpoint_arch_parse

extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,

					   unsigned long val, void *data);

arch/x86/kernel/hw_breakpoint.c

+30 −30
Original line number Diff line number Diff line
@@ -239,19 +239,20 @@ int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw) 
	return (va >= TASK_SIZE_MAX) || ((va + len - 1) >= TASK_SIZE_MAX);

}



static int arch_build_bp_info(struct perf_event *bp)

static int arch_build_bp_info(struct perf_event *bp,

			      const struct perf_event_attr *attr,

			      struct arch_hw_breakpoint *hw)

{

	struct arch_hw_breakpoint *info = counter_arch_bp(bp);



	info->address = bp->attr.bp_addr;

	hw->address = attr->bp_addr;

	hw->mask = 0;



	/* Type */

	switch (bp->attr.bp_type) {

	switch (attr->bp_type) {

	case HW_BREAKPOINT_W:

		info->type = X86_BREAKPOINT_WRITE;

		hw->type = X86_BREAKPOINT_WRITE;

		break;

	case HW_BREAKPOINT_W | HW_BREAKPOINT_R:

		info->type = X86_BREAKPOINT_RW;

		hw->type = X86_BREAKPOINT_RW;

		break;

	case HW_BREAKPOINT_X:

		/*
@@ -259,23 +260,23 @@ static int arch_build_bp_info(struct perf_event *bp) 
		 * acceptable for kprobes.  On non-kprobes kernels, we don't

		 * allow kernel breakpoints at all.

		 */

		if (bp->attr.bp_addr >= TASK_SIZE_MAX) {

		if (attr->bp_addr >= TASK_SIZE_MAX) {

#ifdef CONFIG_KPROBES

			if (within_kprobe_blacklist(bp->attr.bp_addr))

			if (within_kprobe_blacklist(attr->bp_addr))

				return -EINVAL;

#else

			return -EINVAL;

#endif

		}



		info->type = X86_BREAKPOINT_EXECUTE;

		hw->type = X86_BREAKPOINT_EXECUTE;

		/*

		 * x86 inst breakpoints need to have a specific undefined len.

		 * But we still need to check userspace is not trying to setup

		 * an unsupported length, to get a range breakpoint for example.

		 */

		if (bp->attr.bp_len == sizeof(long)) {

			info->len = X86_BREAKPOINT_LEN_X;

		if (attr->bp_len == sizeof(long)) {

			hw->len = X86_BREAKPOINT_LEN_X;

			return 0;

		}

	default:
@@ -283,28 +284,26 @@ static int arch_build_bp_info(struct perf_event *bp) 
	}



	/* Len */

	info->mask = 0;



	switch (bp->attr.bp_len) {

	switch (attr->bp_len) {

	case HW_BREAKPOINT_LEN_1:

		info->len = X86_BREAKPOINT_LEN_1;

		hw->len = X86_BREAKPOINT_LEN_1;

		break;

	case HW_BREAKPOINT_LEN_2:

		info->len = X86_BREAKPOINT_LEN_2;

		hw->len = X86_BREAKPOINT_LEN_2;

		break;

	case HW_BREAKPOINT_LEN_4:

		info->len = X86_BREAKPOINT_LEN_4;

		hw->len = X86_BREAKPOINT_LEN_4;

		break;

#ifdef CONFIG_X86_64

	case HW_BREAKPOINT_LEN_8:

		info->len = X86_BREAKPOINT_LEN_8;

		hw->len = X86_BREAKPOINT_LEN_8;

		break;

#endif

	default:

		/* AMD range breakpoint */

		if (!is_power_of_2(bp->attr.bp_len))

		if (!is_power_of_2(attr->bp_len))

			return -EINVAL;

		if (bp->attr.bp_addr & (bp->attr.bp_len - 1))

		if (attr->bp_addr & (attr->bp_len - 1))

			return -EINVAL;



		if (!boot_cpu_has(X86_FEATURE_BPEXT))
@@ -317,8 +316,8 @@ static int arch_build_bp_info(struct perf_event *bp) 
		 * breakpoints, then we'll have to check for kprobe-blacklisted

		 * addresses anywhere in the range.

		 */

		info->mask = bp->attr.bp_len - 1;

		info->len = X86_BREAKPOINT_LEN_1;

		hw->mask = attr->bp_len - 1;

		hw->len = X86_BREAKPOINT_LEN_1;

	}



	return 0;
@@ -327,22 +326,23 @@ static int arch_build_bp_info(struct perf_event *bp) 
/*

 * Validate the arch-specific HW Breakpoint register settings

 */

int arch_validate_hwbkpt_settings(struct perf_event *bp)

int hw_breakpoint_arch_parse(struct perf_event *bp,

			     const struct perf_event_attr *attr,

			     struct arch_hw_breakpoint *hw)

{

	struct arch_hw_breakpoint *info = counter_arch_bp(bp);

	unsigned int align;

	int ret;





	ret = arch_build_bp_info(bp);

	ret = arch_build_bp_info(bp, attr, hw);

	if (ret)

		return ret;



	switch (info->len) {

	switch (hw->len) {

	case X86_BREAKPOINT_LEN_1:

		align = 0;

		if (info->mask)

			align = info->mask;

		if (hw->mask)

			align = hw->mask;

		break;

	case X86_BREAKPOINT_LEN_2:

		align = 1;
@@ -363,7 +363,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) 
	 * Check that the low-order bits of the address are appropriate

	 * for the alignment implied by len.

	 */

	if (info->address & align)

	if (hw->address & align)

		return -EINVAL;



	return 0;