cregit-Linux how code gets into the kernel

Release 4.14 arch/x86/kernel/kprobes/core.c

Directory: arch/x86/kernel/kprobes
/*
 *  Kernel Probes (KProbes)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2002, 2004
 *
 * 2002-Oct     Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
 *              Probes initial implementation ( includes contributions from
 *              Rusty Russell).
 * 2004-July    Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
 *              interface to access function arguments.
 * 2004-Oct     Jim Keniston <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
 *              <prasanna@in.ibm.com> adapted for x86_64 from i386.
 * 2005-Mar     Roland McGrath <roland@redhat.com>
 *              Fixed to handle %rip-relative addressing mode correctly.
 * 2005-May     Hien Nguyen <hien@us.ibm.com>, Jim Keniston
 *              <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
 *              <prasanna@in.ibm.com> added function-return probes.
 * 2005-May     Rusty Lynch <rusty.lynch@intel.com>
 *              Added function return probes functionality
 * 2006-Feb     Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added
 *              kprobe-booster and kretprobe-booster for i386.
 * 2007-Dec     Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster
 *              and kretprobe-booster for x86-64
 * 2007-Dec     Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven
 *              <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
 *              unified x86 kprobes code.
 */
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
#include <linux/preempt.h>
#include <linux/sched/debug.h>
#include <linux/extable.h>
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
#include <linux/ftrace.h>
#include <linux/frame.h>
#include <linux/kasan.h>
#include <linux/moduleloader.h>

#include <asm/text-patching.h>
#include <asm/cacheflush.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <linux/uaccess.h>
#include <asm/alternative.h>
#include <asm/insn.h>
#include <asm/debugreg.h>
#include <asm/set_memory.h>

#include "common.h"

void jprobe_return_end(void);

DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);


#define stack_addr(regs) ((unsigned long *)kernel_stack_pointer(regs))


#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
	(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) |   \
          (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) |   \
          (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) |   \
          (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf))    \
         << (row % 32))
	/*
         * Undefined/reserved opcodes, conditional jump, Opcode Extension
         * Groups, and some special opcodes can not boost.
         * This is non-const and volatile to keep gcc from statically
         * optimizing it out, as variable_test_bit makes gcc think only
         * *(unsigned long*) is used.
         */

static volatile u32 twobyte_is_boostable[256 / 32] = {
	/*      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f          */
	/*      ----------------------------------------------          */
	W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */
	W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1) , /* 10 */
	W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */
	W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */
	W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */
	W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
	W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */
	W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */
	W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */
	W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
	W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */
	W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */
	W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */
	W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */
	W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */
	W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0)   /* f0 */
	/*      -----------------------------------------------         */
	/*      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f          */
};

#undef W


struct kretprobe_blackpoint kretprobe_blacklist[] = {
	{"__switch_to", }, /* This function switches only current task, but
                              doesn't switch kernel stack.*/
	{NULL, NULL}	/* Terminator */
};


const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);



static nokprobe_inline void

__synthesize_relative_insn(void *from, void *to, u8 op)
{
	struct __arch_relative_insn {
		u8 op;
		s32 raddr;
	} __packed *insn;

	insn = (struct __arch_relative_insn *)from;
	insn->raddr = (s32)((long)(to) - ((long)(from) + 5));
	insn->op = op;
}


Contributors
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Masami Hiramatsu74100.00%4100.00%


Total74100.00%4100.00%



/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/



void synthesize_reljump(void *from, void *to)
{
	__synthesize_relative_insn(from, to, RELATIVEJUMP_OPCODE);
}

Contributors
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Masami Hiramatsu22100.00%3100.00%


Total22100.00%3100.00%




NOKPROBE_SYMBOL(synthesize_reljump);

/* Insert a call instruction at address 'from', which calls address 'to'.*/



void synthesize_relcall(void *from, void *to)
{
	__synthesize_relative_insn(from, to, RELATIVECALL_OPCODE);
}

Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu22100.00%1100.00%


Total22100.00%1100.00%




NOKPROBE_SYMBOL(synthesize_relcall);

/*
 * Skip the prefixes of the instruction.
 */



static kprobe_opcode_t *skip_prefixes(kprobe_opcode_t *insn)
{
	insn_attr_t attr;

	attr = inat_get_opcode_attribute((insn_byte_t)*insn);
	while (inat_is_legacy_prefix(attr)) {
		insn++;
		attr = inat_get_opcode_attribute((insn_byte_t)*insn);
	}
#ifdef CONFIG_X86_64
	if (inat_is_rex_prefix(attr))
		insn++;
#endif
	return insn;
}

Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu4872.73%150.00%


Harvey Harrison1827.27%150.00%


Total66100.00%2100.00%




NOKPROBE_SYMBOL(skip_prefixes);

/*
 * Returns non-zero if INSN is boostable.
 * RIP relative instructions are adjusted at copying time in 64 bits mode
 */



int can_boost(struct insn *insn, void *addr)
{
	kprobe_opcode_t opcode;

	if (search_exception_tables((unsigned long)addr))
		return 0;	/* Page fault may occur on this address. */

	/* 2nd-byte opcode */
	if (insn->opcode.nbytes == 2)
		return test_bit(insn->opcode.bytes[1],
				(unsigned long *)twobyte_is_boostable);

	if (insn->opcode.nbytes != 1)
		return 0;

	/* Can't boost Address-size override prefix */
	if (unlikely(inat_is_address_size_prefix(insn->attr)))
		return 0;

	opcode = insn->opcode.bytes[0];

	switch (opcode & 0xf0) {
	case 0x60:
		/* can't boost "bound" */
		return (opcode != 0x62);
	case 0x70:
		return 0; /* can't boost conditional jump */
	case 0x90:
		return opcode != 0x9a;	/* can't boost call far */
	case 0xc0:
		/* can't boost software-interruptions */
		return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;
	case 0xd0:
		/* can boost AA* and XLAT */
		return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7);
	case 0xe0:
		/* can boost in/out and absolute jmps */
		return ((opcode & 0x04) || opcode == 0xea);
	case 0xf0:
		/* clear and set flags are boostable */
		return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
	default:
		/* CS override prefix and call are not boostable */
		return (opcode != 0x2e && opcode != 0x9a);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu22096.92%675.00%


Jaswinder Singh Rajput41.76%112.50%


Roland McGrath31.32%112.50%


Total227100.00%8100.00%





static unsigned long

__recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr)
{
	struct kprobe *kp;
	unsigned long faddr;

	kp = get_kprobe((void *)addr);
	faddr = ftrace_location(addr);
	/*
         * Addresses inside the ftrace location are refused by
         * arch_check_ftrace_location(). Something went terribly wrong
         * if such an address is checked here.
         */
	if (WARN_ON(faddr && faddr != addr))
		return 0UL;
	/*
         * Use the current code if it is not modified by Kprobe
         * and it cannot be modified by ftrace.
         */
	if (!kp && !faddr)
		return addr;

	/*
         * Basically, kp->ainsn.insn has an original instruction.
         * However, RIP-relative instruction can not do single-stepping
         * at different place, __copy_instruction() tweaks the displacement of
         * that instruction. In that case, we can't recover the instruction
         * from the kp->ainsn.insn.
         *
         * On the other hand, in case on normal Kprobe, kp->opcode has a copy
         * of the first byte of the probed instruction, which is overwritten
         * by int3. And the instruction at kp->addr is not modified by kprobes
         * except for the first byte, we can recover the original instruction
         * from it and kp->opcode.
         *
         * In case of Kprobes using ftrace, we do not have a copy of
         * the original instruction. In fact, the ftrace location might
         * be modified at anytime and even could be in an inconsistent state.
         * Fortunately, we know that the original code is the ideal 5-byte
         * long NOP.
         */
	if (probe_kernel_read(buf, (void *)addr,
		MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
		return 0UL;

	if (faddr)
		memcpy(buf, ideal_nops[NOP_ATOMIC5], 5);
	else
		buf[0] = kp->opcode;
	return (unsigned long)buf;
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu7458.73%360.00%


Petr Mladek5241.27%240.00%


Total126100.00%5100.00%



/*
 * Recover the probed instruction at addr for further analysis.
 * Caller must lock kprobes by kprobe_mutex, or disable preemption
 * for preventing to release referencing kprobes.
 * Returns zero if the instruction can not get recovered (or access failed).
 */



unsigned long recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
{
	unsigned long __addr;

	__addr = __recover_optprobed_insn(buf, addr);
	if (__addr != addr)
		return __addr;

	return __recover_probed_insn(buf, addr);
}


Contributors
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Masami Hiramatsu44100.00%2100.00%


Total44100.00%2100.00%



/* Check if paddr is at an instruction boundary */



static int can_probe(unsigned long paddr)
{
	unsigned long addr, __addr, offset = 0;
	struct insn insn;
	kprobe_opcode_t buf[MAX_INSN_SIZE];

	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
		return 0;

	/* Decode instructions */
	addr = paddr - offset;
	while (addr < paddr) {
		/*
                 * Check if the instruction has been modified by another
                 * kprobe, in which case we replace the breakpoint by the
                 * original instruction in our buffer.
                 * Also, jump optimization will change the breakpoint to
                 * relative-jump. Since the relative-jump itself is
                 * normally used, we just go through if there is no kprobe.
                 */
		__addr = recover_probed_instruction(buf, addr);
		if (!__addr)
			return 0;
		kernel_insn_init(&insn, (void *)__addr, MAX_INSN_SIZE);
		insn_get_length(&insn);

		/*
                 * Another debugging subsystem might insert this breakpoint.
                 * In that case, we can't recover it.
                 */
		if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
			return 0;
		addr += insn.length;
	}

	return (addr == paddr);
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu11891.47%240.00%


Petr Mladek86.20%120.00%


Dave Hansen21.55%120.00%


Namhyung Kim10.78%120.00%


Total129100.00%5100.00%



/*
 * Returns non-zero if opcode modifies the interrupt flag.
 */



static int is_IF_modifier(kprobe_opcode_t *insn)
{
	/* Skip prefixes */
	insn = skip_prefixes(insn);

	switch (*insn) {
	case 0xfa:		/* cli */
	case 0xfb:		/* sti */
	case 0xcf:		/* iret/iretd */
	case 0x9d:		/* popf/popfd */
		return 1;
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu4493.62%266.67%


Roland McGrath36.38%133.33%


Total47100.00%3100.00%



/*
 * Copy an instruction with recovering modified instruction by kprobes
 * and adjust the displacement if the instruction uses the %rip-relative
 * addressing mode.
 * This returns the length of copied instruction, or 0 if it has an error.
 */



int __copy_instruction(u8 *dest, u8 *src, struct insn *insn)
{
	kprobe_opcode_t buf[MAX_INSN_SIZE];
	unsigned long recovered_insn =
		recover_probed_instruction(buf, (unsigned long)src);

	if (!recovered_insn || !insn)
		return 0;

	/* This can access kernel text if given address is not recovered */
	if (probe_kernel_read(dest, (void *)recovered_insn, MAX_INSN_SIZE))
		return 0;

	kernel_insn_init(insn, dest, MAX_INSN_SIZE);
	insn_get_length(insn);

	/* Another subsystem puts a breakpoint, failed to recover */
	if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
		return 0;

#ifdef CONFIG_X86_64
	/* Only x86_64 has RIP relative instructions */
	if (insn_rip_relative(insn)) {
		s64 newdisp;
		u8 *disp;
		/*
                 * The copied instruction uses the %rip-relative addressing
                 * mode.  Adjust the displacement for the difference between
                 * the original location of this instruction and the location
                 * of the copy that will actually be run.  The tricky bit here
                 * is making sure that the sign extension happens correctly in
                 * this calculation, since we need a signed 32-bit result to
                 * be sign-extended to 64 bits when it's added to the %rip
                 * value and yield the same 64-bit result that the sign-
                 * extension of the original signed 32-bit displacement would
                 * have given.
                 */
		newdisp = (u8 *) src + (s64) insn->displacement.value
			  - (u8 *) dest;
		if ((s64) (s32) newdisp != newdisp) {
			pr_err("Kprobes error: new displacement does not fit into s32 (%llx)\n", newdisp);
			pr_err("\tSrc: %p, Dest: %p, old disp: %x\n",
				src, dest, insn->displacement.value);
			return 0;
		}
		disp = (u8 *) dest + insn_offset_displacement(insn);
		*(s32 *) disp = (s32) newdisp;
	}
#endif
	return insn->length;
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu16074.42%964.29%


Roland McGrath3013.95%17.14%


Dave Hansen146.51%17.14%


Petr Mladek83.72%17.14%


Eugene Shatokhin20.93%17.14%


Harvey Harrison10.47%17.14%


Total215100.00%14100.00%



/* Prepare reljump right after instruction to boost */



static void prepare_boost(struct kprobe *p, struct insn *insn)
{
	if (can_boost(insn, p->addr) &&
	    MAX_INSN_SIZE - insn->length >= RELATIVEJUMP_SIZE) {
		/*
                 * These instructions can be executed directly if it
                 * jumps back to correct address.
                 */
		synthesize_reljump(p->ainsn.insn + insn->length,
				   p->addr + insn->length);
		p->ainsn.boostable = true;
	} else {
		p->ainsn.boostable = false;
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu78100.00%8100.00%


Total78100.00%8100.00%



/* Recover page to RW mode before releasing it */



void free_insn_page(void *page)
{
	set_memory_nx((unsigned long)page & PAGE_MASK, 1);
	set_memory_rw((unsigned long)page & PAGE_MASK, 1);
	module_memfree(page);
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu40100.00%1100.00%


Total40100.00%1100.00%






static int arch_copy_kprobe(struct kprobe *p)
{
	struct insn insn;
	int len;

	set_memory_rw((unsigned long)p->ainsn.insn & PAGE_MASK, 1);

	/* Copy an instruction with recovering if other optprobe modifies it.*/
	len = __copy_instruction(p->ainsn.insn, p->addr, &insn);
	if (!len)
		return -EINVAL;

	/*
         * __copy_instruction can modify the displacement of the instruction,
         * but it doesn't affect boostable check.
         */
	prepare_boost(p, &insn);

	set_memory_ro((unsigned long)p->ainsn.insn & PAGE_MASK, 1);

	/* Check whether the instruction modifies Interrupt Flag or not */
	p->ainsn.if_modifier = is_IF_modifier(p->ainsn.insn);

	/* Also, displacement change doesn't affect the first byte */
	p->opcode = p->ainsn.insn[0];

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu11493.44%675.00%


Rusty Lynch75.74%112.50%


Prasanna S. Panchamukhi10.82%112.50%


Total122100.00%8100.00%






int arch_prepare_kprobe(struct kprobe *p)
{
	int ret;

	if (alternatives_text_reserved(p->addr, p->addr))
		return -EINVAL;

	if (!can_probe((unsigned long)p->addr))
		return -EILSEQ;
	/* insn: must be on special executable page on x86. */
	p->ainsn.insn = get_insn_slot();
	if (!p->ainsn.insn)
		return -ENOMEM;

	ret = arch_copy_kprobe(p);
	if (ret) {
		free_insn_slot(p->ainsn.insn, 0);
		p->ainsn.insn = NULL;
	}

	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu106100.00%4100.00%


Total106100.00%4100.00%






void arch_arm_kprobe(struct kprobe *p)
{
	text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
}


Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi1446.67%250.00%


Andi Kleen1033.33%125.00%


Rusty Lynch620.00%125.00%


Total30100.00%4100.00%






void arch_disarm_kprobe(struct kprobe *p)
{
	text_poke(p->addr, &p->opcode, 1);
}


Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi1145.83%133.33%


Rusty Lynch833.33%133.33%


Andi Kleen520.83%133.33%


Total24100.00%3100.00%






void arch_remove_kprobe(struct kprobe *p)
{
	if (p->ainsn.insn) {
		free_insn_slot(p->ainsn.insn, p->ainsn.boostable);
		p->ainsn.insn = NULL;
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu2353.49%350.00%


Rusty Lynch1841.86%116.67%


Anil S Keshavamurthy12.33%116.67%


Prasanna S. Panchamukhi12.33%116.67%


Total43100.00%6100.00%





static nokprobe_inline void

save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
	kcb->prev_kprobe.kp = kprobe_running();
	kcb->prev_kprobe.status = kcb->kprobe_status;
	kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags;
	kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
}


Contributors
PersonTokensPropCommitsCommitProp
Ananth N. Mavinakayanahalli3058.82%125.00%


Prasanna S. Panchamukhi1631.37%125.00%


Masami Hiramatsu59.80%250.00%


Total51100.00%4100.00%





static nokprobe_inline void

restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
	kcb->kprobe_status = kcb->prev_kprobe.status;
	kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags;
	kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
}


Contributors
PersonTokensPropCommitsCommitProp
Ananth N. Mavinakayanahalli2954.72%120.00%


Prasanna S. Panchamukhi1630.19%120.00%


Masami Hiramatsu59.43%240.00%


Christoph Lameter35.66%120.00%


Total53100.00%5100.00%





static nokprobe_inline void

set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
		   struct kprobe_ctlblk *kcb)
{
	__this_cpu_write(current_kprobe, p);
	kcb->kprobe_saved_flags = kcb->kprobe_old_flags
		= (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF));
	if (p->ainsn.if_modifier)
		kcb->kprobe_saved_flags &= ~X86_EFLAGS_IF;
}


Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi4062.50%112.50%


Ananth N. Mavinakayanahalli1218.75%112.50%


Masami Hiramatsu57.81%337.50%


Christoph Lameter34.69%112.50%


Glauber de Oliveira Costa34.69%112.50%


H. Peter Anvin11.56%112.50%


Total64100.00%8100.00%






static nokprobe_inline void clear_btf(void)
{
	if (test_thread_flag(TIF_BLOCKSTEP)) {
		unsigned long debugctl = get_debugctlmsr();

		debugctl &= ~DEBUGCTLMSR_BTF;
		update_debugctlmsr(debugctl);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Roland McGrath1851.43%125.00%


Peter Zijlstra1542.86%125.00%


Masami Hiramatsu12.86%125.00%


Jan Beulich12.86%125.00%


Total35100.00%4100.00%






static nokprobe_inline void restore_btf(void)
{
	if (test_thread_flag(TIF_BLOCKSTEP)) {
		unsigned long debugctl = get_debugctlmsr();

		debugctl |= DEBUGCTLMSR_BTF;
		update_debugctlmsr(debugctl);
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Roland McGrath1852.94%125.00%


Peter Zijlstra1441.18%125.00%


Masami Hiramatsu12.94%125.00%


Jan Beulich12.94%125.00%


Total34100.00%4100.00%






void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	unsigned long *sara = stack_addr(regs);

	ri->ret_addr = (kprobe_opcode_t *) *sara;

	/* Replace the return addr with trampoline addr */
	*sara = (unsigned long) &kretprobe_trampoline;
}

Contributors
PersonTokensPropCommitsCommitProp
Rusty Lynch4187.23%240.00%


Masami Hiramatsu48.51%240.00%


Christoph Hellwig24.26%120.00%


Total47100.00%5100.00%




NOKPROBE_SYMBOL(arch_prepare_kretprobe);




static void setup_singlestep(struct kprobe *p, struct pt_regs *regs,
			     struct kprobe_ctlblk *kcb, int reenter)
{
	if (setup_detour_execution(p, regs, reenter))
		return;

#if !defined(CONFIG_PREEMPT)
	if (p->ainsn.boostable && !p->post_handler) {
		/* Boost up -- we can execute copied instructions directly */
		if (!reenter)
			reset_current_kprobe();
		/*
                 * Reentering boosted probe doesn't reset current_kprobe,
                 * nor set current_kprobe, because it doesn't use single
                 * stepping.
                 */
		regs->ip = (unsigned long)p->ainsn.insn;
		preempt_enable_no_resched();
		return;
	}
#endif
	if (reenter) {
		save_previous_kprobe(kcb);
		set_current_kprobe(p, regs, kcb);
		kcb->kprobe_status = KPROBE_REENTER;
	} else
		kcb->kprobe_status = KPROBE_HIT_SS;
	/* Prepare real single stepping */
	clear_btf();
	regs->flags |= X86_EFLAGS_TF;
	regs->flags &= ~X86_EFLAGS_IF;
	/* single step inline if the instruction is an int3 */
	if (p->opcode == BREAKPOINT_INSTRUCTION)
		regs->ip = (unsigned long)p->addr;
	else
		regs->ip = (unsigned long)p->ainsn.insn;
}

Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu11264.37%480.00%


Abhishek Sagar6235.63%120.00%


Total174100.00%5100.00%




NOKPROBE_SYMBOL(setup_singlestep);

/*
 * We have reentered the kprobe_handler(), since another probe was hit while
 * within the handler. We save the original kprobes variables and just single
 * step on the instruction of the new probe without calling any user handlers.
 */



static int reenter_kprobe(struct kprobe *p, struct pt_regs *regs,
			  struct kprobe_ctlblk *kcb)
{
	switch (kcb->kprobe_status) {
	case KPROBE_HIT_SSDONE:
	case KPROBE_HIT_ACTIVE:
	case KPROBE_HIT_SS:
		kprobes_inc_nmissed_count(p);
		setup_singlestep(p, regs, kcb, 1);
		break;
	case KPROBE_REENTER:
		/* A probe has been hit in the codepath leading up to, or just
                 * after, single-stepping of a probed instruction. This entire
                 * codepath should strictly reside in .kprobes.text section.
                 * Raise a BUG or we'll continue in an endless reentering loop
                 * and eventually a stack overflow.
                 */
		printk(KERN_WARNING "Unrecoverable kprobe detected at %p.\n",
		       p->addr);
		dump_kprobe(p);
		BUG();
	default:
		/* impossible cases */
		WARN_ON(1);
		return 0;
	}

	return 1;
}

Contributors
PersonTokensPropCommitsCommitProp
Abhishek Sagar4651.11%225.00%


Masami Hiramatsu2426.67%450.00%


Frédéric Weisbecker1213.33%112.50%


Harvey Harrison88.89%112.50%


Total90100.00%8100.00%




NOKPROBE_SYMBOL(reenter_kprobe);

/*
 * Interrupts are disabled on entry as trap3 is an interrupt gate and they
 * remain disabled throughout this function.
 */



int kprobe_int3_handler(struct pt_regs *regs)
{
	kprobe_opcode_t *addr;
	struct kprobe *p;
	struct kprobe_ctlblk *kcb;

	if (user_mode(regs))
		return 0;

	addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
	/*
         * We don't want to be preempted for the entire
         * duration of kprobe processing. We conditionally
         * re-enable preemption at the end of this function,
         * and also in reenter_kprobe() and setup_singlestep().
         */
	preempt_disable();

	kcb = get_kprobe_ctlblk();
	p = get_kprobe(addr);

	if (p) {
		if (kprobe_running()) {
			if (reenter_kprobe(p, regs, kcb))
				return 1;
		} else {
			set_current_kprobe(p, regs, kcb);
			kcb->kprobe_status = KPROBE_HIT_ACTIVE;

			/*
                         * If we have no pre-handler or it returned 0, we
                         * continue with normal processing.  If we have a
                         * pre-handler and it returned non-zero, it prepped
                         * for calling the break_handler below on re-entry
                         * for jprobe processing, so get out doing nothing
                         * more here.
                         */
			if (!p->pre_handler || !p->pre_handler(p, regs))
				setup_singlestep(p, regs, kcb, 0);
			return 1;
		}
	} else if (*addr != BREAKPOINT_INSTRUCTION) {
		/*
                 * The breakpoint instruction was removed right
                 * after we hit it.  Another cpu has removed
                 * either a probepoint or a debugger breakpoint
                 * at this address.  In either case, no further
                 * handling of this interrupt is appropriate.
                 * Back up over the (now missing) int3 and run
                 * the original instruction.
                 */
		regs->ip = (unsigned long)addr;
		preempt_enable_no_resched();
		return 1;
	} else if (kprobe_running()) {
		p = __this_cpu_read(current_kprobe);
		if (p->break_handler && p->break_handler(p, regs)) {
			if (!skip_singlestep(p, regs, kcb))
				setup_singlestep(p, regs, kcb, 0);
			return 1;
		}
	} /* else: not a kprobe fault; let the kernel handle it */

	preempt_enable_no_resched();
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi7732.63%29.09%


Masami Hiramatsu5422.88%836.36%


Harvey Harrison3514.83%29.09%


Abhishek Sagar3414.41%14.55%


Ananth N. Mavinakayanahalli218.90%313.64%


Andrew Lutomirski104.24%29.09%


James Keniston20.85%14.55%


Christoph Lameter10.42%14.55%


Anil S Keshavamurthy10.42%14.55%


H. Peter Anvin10.42%14.55%


Total236100.00%22100.00%




NOKPROBE_SYMBOL(kprobe_int3_handler);

/*
 * When a retprobed function returns, this code saves registers and
 * calls trampoline_handler() runs, which calls the kretprobe's handler.
 */
asm(
        ".global kretprobe_trampoline\n"
        ".type kretprobe_trampoline, @function\n"
        "kretprobe_trampoline:\n"
#ifdef CONFIG_X86_64
	/* We don't bother saving the ss register */
	"       pushq %rsp\n"
        "       pushfq\n"
        SAVE_REGS_STRING
        "       movq %rsp, %rdi\n"
        "       call trampoline_handler\n"
	/* Replace saved sp with true return address. */
	"       movq %rax, 152(%rsp)\n"
        RESTORE_REGS_STRING
        "       popfq\n"
#else
	"       pushf\n"
        SAVE_REGS_STRING
        "       movl %esp, %eax\n"
        "       call trampoline_handler\n"
	/* Move flags to cs */
	"       movl 56(%esp), %edx\n"
        "       movl %edx, 52(%esp)\n"
	/* Replace saved flags with true return address. */
	"       movl %eax, 56(%esp)\n"
        RESTORE_REGS_STRING
        "       popf\n"
#endif
	"       ret\n"
        ".size kretprobe_trampoline, .-kretprobe_trampoline\n"
);

NOKPROBE_SYMBOL(kretprobe_trampoline);

STACK_FRAME_NON_STANDARD(kretprobe_trampoline);

/*
 * Called from kretprobe_trampoline
 */



__visible __used void *trampoline_handler(struct pt_regs *regs)
{
	struct kretprobe_instance *ri = NULL;
	struct hlist_head *head, empty_rp;
	struct hlist_node *tmp;
	unsigned long flags, orig_ret_address = 0;
	unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
	kprobe_opcode_t *correct_ret_addr = NULL;

	INIT_HLIST_HEAD(&empty_rp);
	kretprobe_hash_lock(current, &head, &flags);
	/* fixup registers */
#ifdef CONFIG_X86_64
	regs->cs = __KERNEL_CS;
#else
	regs->cs = __KERNEL_CS | get_kernel_rpl();
	regs->gs = 0;
#endif
	regs->ip = trampoline_address;
	regs->orig_ax = ~0UL;

	/*
         * It is possible to have multiple instances associated with a given
         * task either because multiple functions in the call path have
         * return probes installed on them, and/or more than one
         * return probe was registered for a target function.
         *
         * We can handle this because:
         *     - instances are always pushed into the head of the list
         *     - when multiple return probes are registered for the same
         *       function, the (chronologically) first instance's ret_addr
         *       will be the real return address, and all the rest will
         *       point to kretprobe_trampoline.
         */
	hlist_for_each_entry(ri, head, hlist) {
		if (ri->task != current)
			/* another task is sharing our hash bucket */
			continue;

		orig_ret_address = (unsigned long)ri->ret_addr;

		if (orig_ret_address != trampoline_address)
			/*
                         * This is the real return address. Any other
                         * instances associated with this task are for
                         * other calls deeper on the call stack
                         */
			break;
	}

	kretprobe_assert(ri, orig_ret_address, trampoline_address);

	correct_ret_addr = ri->ret_addr;
	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
		if (ri->task != current)
			/* another task is sharing our hash bucket */
			continue;

		orig_ret_address = (unsigned long)ri->ret_addr;
		if (ri->rp && ri->rp->handler) {
			__this_cpu_write(current_kprobe, &ri->rp->kp);
			get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
			ri->ret_addr = correct_ret_addr;
			ri->rp->handler(ri, regs);
			__this_cpu_write(current_kprobe, NULL);
		}

		recycle_rp_inst(ri, &empty_rp);

		if (orig_ret_address != trampoline_address)
			/*
                         * This is the real return address. Any other
                         * instances associated with this task are for
                         * other calls deeper on the call stack
                         */
			break;
	}

	kretprobe_hash_unlock(current, &flags);

	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
		hlist_del(&ri->hlist);
		kfree(ri);
	}
	return (void *)orig_ret_address;
}

Contributors
PersonTokensPropCommitsCommitProp
Rusty Lynch10031.75%213.33%


KUMANO Syuhei7724.44%16.67%


Masami Hiramatsu7323.17%533.33%


Bibo Mao3611.43%16.67%


Ananth N. Mavinakayanahalli123.81%16.67%


Srinivasa D S82.54%16.67%


Christoph Lameter61.90%16.67%


Frederik Schwarzer10.32%16.67%


Harvey Harrison10.32%16.67%


Andi Kleen10.32%16.67%


Total315100.00%15100.00%




NOKPROBE_SYMBOL(trampoline_handler);

/*
 * Called after single-stepping.  p->addr is the address of the
 * instruction whose first byte has been replaced by the "int 3"
 * instruction.  To avoid the SMP problems that can occur when we
 * temporarily put back the original opcode to single-step, we
 * single-stepped a copy of the instruction.  The address of this
 * copy is p->ainsn.insn.
 *
 * This function prepares to return from the post-single-step
 * interrupt.  We have to fix up the stack as follows:
 *
 * 0) Except in the case of absolute or indirect jump or call instructions,
 * the new ip is relative to the copied instruction.  We need to make
 * it relative to the original instruction.
 *
 * 1) If the single-stepped instruction was pushfl, then the TF and IF
 * flags are set in the just-pushed flags, and may need to be cleared.
 *
 * 2) If the single-stepped instruction was a call, the return address
 * that is atop the stack is the address following the copied instruction.
 * We need to make it the address following the original instruction.
 *
 * If this is the first time we've single-stepped the instruction at
 * this probepoint, and the instruction is boostable, boost it: add a
 * jump instruction after the copied instruction, that jumps to the next
 * instruction after the probepoint.
 */



static void resume_execution(struct kprobe *p, struct pt_regs *regs,
			     struct kprobe_ctlblk *kcb)
{
	unsigned long *tos = stack_addr(regs);
	unsigned long copy_ip = (unsigned long)p->ainsn.insn;
	unsigned long orig_ip = (unsigned long)p->addr;
	kprobe_opcode_t *insn = p->ainsn.insn;

	/* Skip prefixes */
	insn = skip_prefixes(insn);

	regs->flags &= ~X86_EFLAGS_TF;
	switch (*insn) {
	case 0x9c:	/* pushfl */
		*tos &= ~(X86_EFLAGS_TF | X86_EFLAGS_IF);
		*tos |= kcb->kprobe_old_flags;
		break;
	case 0xc2:	/* iret/ret/lret */
	case 0xc3:
	case 0xca:
	case 0xcb:
	case 0xcf:
	case 0xea:	/* jmp absolute -- ip is correct */
		/* ip is already adjusted, no more changes required */
		p->ainsn.boostable = true;
		goto no_change;
	case 0xe8:	/* call relative - Fix return addr */
		*tos = orig_ip + (*tos - copy_ip);
		break;
#ifdef CONFIG_X86_32
	case 0x9a:	/* call absolute -- same as call absolute, indirect */
		*tos = orig_ip + (*tos - copy_ip);
		goto no_change;
#endif
	case 0xff:
		if ((insn[1] & 0x30) == 0x10) {
			/*
                         * call absolute, indirect
                         * Fix return addr; ip is correct.
                         * But this is not boostable
                         */
			*tos = orig_ip + (*tos - copy_ip);
			goto no_change;
		} else if (((insn[1] & 0x31) == 0x20) ||
			   ((insn[1] & 0x31) == 0x21)) {
			/*
                         * jmp near and far, absolute indirect
                         * ip is correct. And this is boostable
                         */
			p->ainsn.boostable = true;
			goto no_change;
		}
	default:
		break;
	}

	regs->ip += orig_ip - copy_ip;

no_change:
	restore_btf();
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi16459.42%213.33%


Masami Hiramatsu8330.07%640.00%


Satoshi Oshima93.26%16.67%


Ananth N. Mavinakayanahalli72.54%16.67%


Harvey Harrison51.81%213.33%


Glauber de Oliveira Costa31.09%16.67%


Roland McGrath31.09%16.67%


H. Peter Anvin20.72%16.67%


Total276100.00%15100.00%




NOKPROBE_SYMBOL(resume_execution);

/*
 * Interrupts are disabled on entry as trap1 is an interrupt gate and they
 * remain disabled throughout this function.
 */



int kprobe_debug_handler(struct pt_regs *regs)
{
	struct kprobe *cur = kprobe_running();
	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	if (!cur)
		return 0;

	resume_execution(cur, regs, kcb);
	regs->flags |= kcb->kprobe_saved_flags;

	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
		kcb->kprobe_status = KPROBE_HIT_SSDONE;
		cur->post_handler(cur, regs, 0);
	}

	/* Restore back the original saved kprobes variables and continue. */
	if (kcb->kprobe_status == KPROBE_REENTER) {
		restore_previous_kprobe(kcb);
		goto out;
	}
	reset_current_kprobe();
out:
	preempt_enable_no_resched();

	/*
         * if somebody else is singlestepping across a probe point, flags
         * will have TF set, in which case, continue the remaining processing
         * of do_debug, as if this is not a probe hit.
         */
	if (regs->flags & X86_EFLAGS_TF)
		return 0;

	return 1;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi7257.14%225.00%


Ananth N. Mavinakayanahalli3225.40%112.50%


Yakov Lerner1713.49%112.50%


Masami Hiramatsu21.59%225.00%


H. Peter Anvin21.59%112.50%


Glauber de Oliveira Costa10.79%112.50%


Total126100.00%8100.00%




NOKPROBE_SYMBOL(kprobe_debug_handler);




int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
	struct kprobe *cur = kprobe_running();
	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	if (unlikely(regs->ip == (unsigned long)cur->ainsn.insn)) {
		/* This must happen on single-stepping */
		WARN_ON(kcb->kprobe_status != KPROBE_HIT_SS &&
			kcb->kprobe_status != KPROBE_REENTER);
		/*
                 * We are here because the instruction being single
                 * stepped caused a page fault. We reset the current
                 * kprobe and the ip points back to the probe address
                 * and allow the page fault handler to continue as a
                 * normal page fault.
                 */
		regs->ip = (unsigned long)cur->addr;
		/*
                 * Trap flag (TF) has been set here because this fault
                 * happened where the single stepping will be done.
                 * So clear it by resetting the current kprobe:
                 */
		regs->flags &= ~X86_EFLAGS_TF;

		/*
                 * If the TF flag was set before the kprobe hit,
                 * don't touch it:
                 */
		regs->flags |= kcb->kprobe_old_flags;

		if (kcb->kprobe_status == KPROBE_REENTER)
			restore_previous_kprobe(kcb);
		else
			reset_current_kprobe();
		preempt_enable_no_resched();
	} else if (kcb->kprobe_status == KPROBE_HIT_ACTIVE ||
		   kcb->kprobe_status == KPROBE_HIT_SSDONE) {
		/*
                 * We increment the nmissed count for accounting,
                 * we can also use npre/npostfault count for accounting
                 * these specific fault cases.
                 */
		kprobes_inc_nmissed_count(cur);

		/*
                 * We come here because instructions in the pre/post
                 * handler caused the page_fault, this could happen
                 * if handler tries to access user space by
                 * copy_from_user(), get_user() etc. Let the
                 * user-specified handler try to fix it first.
                 */
		if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
			return 1;

		/*
                 * In case the user-specified fault handler returned
                 * zero, try to fix up.
                 */
		if (fixup_exception(regs, trapnr))
			return 1;

		/*
                 * fixup routine could not handle it,
                 * Let do_page_fault() fix it.
                 */
	}

	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi8648.59%222.22%


Masami Hiramatsu6737.85%444.44%


Ananth N. Mavinakayanahalli1910.73%111.11%


H. Peter Anvin31.69%111.11%


Tony Luck21.13%111.11%


Total177100.00%9100.00%




NOKPROBE_SYMBOL(kprobe_fault_handler);

/*
 * Wrapper routine for handling exceptions.
 */



int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
			     void *data)
{
	struct die_args *args = data;
	int ret = NOTIFY_DONE;

	if (args->regs && user_mode(args->regs))
		return ret;

	if (val == DIE_GPF) {
		/*
                 * To be potentially processing a kprobe fault and to
                 * trust the result from kprobe_running(), we have
                 * be non-preemptible.
                 */
		if (!preemptible() && kprobe_running() &&
		    kprobe_fault_handler(args->regs, args->trapnr))
			ret = NOTIFY_STOP;
	}
	return ret;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi4757.32%112.50%


Bibo Mao1518.29%112.50%


Ananth N. Mavinakayanahalli910.98%112.50%


Quentin Barnes56.10%112.50%


Masami Hiramatsu44.88%225.00%


K.Prasad11.22%112.50%


Andrew Lutomirski11.22%112.50%


Total82100.00%8100.00%




NOKPROBE_SYMBOL(kprobe_exceptions_notify);




int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
	struct jprobe *jp = container_of(p, struct jprobe, kp);
	unsigned long addr;
	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	kcb->jprobe_saved_regs = *regs;
	kcb->jprobe_saved_sp = stack_addr(regs);
	addr = (unsigned long)(kcb->jprobe_saved_sp);

	/*
         * As Linus pointed out, gcc assumes that the callee
         * owns the argument space and could overwrite it, e.g.
         * tailcall optimization. So, to be absolutely safe
         * we also save and restore enough stack bytes to cover
         * the argument area.
         * Use __memcpy() to avoid KASAN stack out-of-bounds reports as we copy
         * raw stack chunk with redzones:
         */
	__memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr));
	regs->ip = (unsigned long)(jp->entry);

	/*
         * jprobes use jprobe_return() which skips the normal return
         * path of the function, and this messes up the accounting of the
         * function graph tracer to get messed up.
         *
         * Pause function graph tracing while performing the jprobe function.
         */
	pause_graph_tracing();
	return 1;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi7870.91%116.67%


Ananth N. Mavinakayanahalli2018.18%116.67%


Masami Hiramatsu54.55%116.67%


Steven Rostedt43.64%116.67%


Dmitriy Vyukov21.82%116.67%


H. Peter Anvin10.91%116.67%


Total110100.00%6100.00%




NOKPROBE_SYMBOL(setjmp_pre_handler);




void jprobe_return(void)
{
	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	/* Unpoison stack redzones in the frames we are going to jump over. */
	kasan_unpoison_stack_above_sp_to(kcb->jprobe_saved_sp);

	asm volatile (
#ifdef CONFIG_X86_64
			"       xchg   %%rbx,%%rsp      \n"
#else
			"       xchgl   %%ebx,%%esp     \n"
#endif
			"       int3                    \n"
                        "       .globl jprobe_return_end\n"
                        "       jprobe_return_end:      \n"
                        "       nop                     \n"::"b"
                        (kcb->jprobe_saved_sp):"memory");
}

Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu1130.56%125.00%


Prasanna S. Panchamukhi925.00%125.00%


Ananth N. Mavinakayanahalli822.22%125.00%


Dmitriy Vyukov822.22%125.00%


Total36100.00%4100.00%




NOKPROBE_SYMBOL(jprobe_return);

NOKPROBE_SYMBOL(jprobe_return_end);




int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
	u8 *addr = (u8 *) (regs->ip - 1);
	struct jprobe *jp = container_of(p, struct jprobe, kp);
	void *saved_sp = kcb->jprobe_saved_sp;

	if ((addr > (u8 *) jprobe_return) &&
	    (addr < (u8 *) jprobe_return_end)) {
		if (stack_addr(regs) != saved_sp) {
			struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
			printk(KERN_ERR
			       "current sp %p does not match saved sp %p\n",
			       stack_addr(regs), saved_sp);
			printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
			show_regs(saved_regs);
			printk(KERN_ERR "Current registers\n");
			show_regs(regs);
			BUG();
		}
		/* It's OK to start function graph tracing again */
		unpause_graph_tracing();
		*regs = kcb->jprobe_saved_regs;
		__memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
		preempt_enable_no_resched();
		return 1;
	}
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Prasanna S. Panchamukhi13272.93%110.00%


Ananth N. Mavinakayanahalli179.39%220.00%


Steven Rostedt168.84%110.00%


Masami Hiramatsu116.08%330.00%


Jan Beulich21.10%110.00%


H. Peter Anvin21.10%110.00%


Dmitriy Vyukov10.55%110.00%


Total181100.00%10100.00%




NOKPROBE_SYMBOL(longjmp_break_handler);




bool arch_within_kprobe_blacklist(unsigned long addr)
{
	return  (addr >= (unsigned long)__kprobes_text_start &&
		 addr < (unsigned long)__kprobes_text_end) ||
		(addr >= (unsigned long)__entry_text_start &&
		 addr < (unsigned long)__entry_text_end);
}


Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu46100.00%1100.00%


Total46100.00%1100.00%






int __init arch_init_kprobes(void)
{
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Rusty Lynch1090.91%266.67%


Masami Hiramatsu19.09%133.33%


Total11100.00%3100.00%






int arch_trampoline_kprobe(struct kprobe *p)
{
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Ananth N. Mavinakayanahalli13100.00%1100.00%


Total13100.00%1100.00%




Overall Contributors
PersonTokensPropCommitsCommitProp
Masami Hiramatsu253256.29%4840.00%


Prasanna S. Panchamukhi79417.65%54.17%


Ananth N. Mavinakayanahalli2485.51%65.00%


Rusty Lynch1924.27%43.33%


Abhishek Sagar1433.18%21.67%


KUMANO Syuhei771.71%10.83%


Roland McGrath751.67%21.67%


Harvey Harrison681.51%65.00%


Petr Mladek681.51%21.67%


Bibo Mao511.13%21.67%


Peter Zijlstra290.64%10.83%


Steven Rostedt200.44%10.83%


Andi Kleen180.40%21.67%


Yakov Lerner170.38%10.83%


Dave Hansen160.36%10.83%


Josh Poimboeuf150.33%21.67%


Dmitriy Vyukov140.31%21.67%


Andrew Lutomirski140.31%32.50%


Christoph Lameter130.29%10.83%


H. Peter Anvin130.29%21.67%


Frédéric Weisbecker120.27%10.83%


Satoshi Oshima90.20%10.83%


Quentin Barnes80.18%10.83%


Srinivasa D S80.18%10.83%


Glauber de Oliveira Costa70.16%10.83%


Ingo Molnar50.11%21.67%


Jan Beulich40.09%21.67%


Jaswinder Singh Rajput40.09%10.83%


Laura Abbott30.07%10.83%


Christoph Hellwig30.07%21.67%


James Keniston20.04%10.83%


K.Prasad20.04%10.83%


Tony Luck20.04%10.83%


Anil S Keshavamurthy20.04%21.67%


Eugene Shatokhin20.04%10.83%


André Goddard Rosa20.04%10.83%


Wang Nan10.02%10.83%


Linus Torvalds10.02%10.83%


Josh Stone10.02%10.83%


Namhyung Kim10.02%10.83%


Paul Gortmaker10.02%10.83%


Frederik Schwarzer10.02%10.83%


Total4498100.00%120100.00%


Directory: arch/x86/kernel/kprobes



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