Commit 08ed38b6 authored by Tony Luck's avatar Tony Luck
Browse files

[IA64] enable trap code on slot 1 



Because slot 1 of one instr bundle crosses border of two consecutive
8-bytes, kprobe on slot 1 is disabled. This patch enables kprobe on
slot1, it only replaces higher 8-bytes of the instruction bundle and
changes the exception code to ignore the low 12 bits of the break
number (which is across the border in the lower 8-bytes of the bundle).

For those instructions which must execute regardless qp bits,
kprobe on slot 1 is still disabled.

Signed-off-by: default avatarbibo,mao <bibo.mao@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 75f6a1de

arch/ia64/kernel/jprobes.S

+2 −1
Original line number Diff line number Diff line
@@ -45,13 +45,14 @@ 
 * to the correct location.

 */

#include <asm/asmmacro.h>

#include <asm-ia64/break.h>



	/*

	 * void jprobe_break(void)

	 */

	.section .kprobes.text, "ax"

ENTRY(jprobe_break)

	break.m 0x80300

	break.m __IA64_BREAK_JPROBE

END(jprobe_break)



	/*

arch/ia64/kernel/kprobes.c

+37 −14
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint slot, 
{

	p->ainsn.inst_flag = 0;

	p->ainsn.target_br_reg = 0;

	p->ainsn.slot = slot;



	/* Check for Break instruction

	 * Bits 37:40 Major opcode to be zero
@@ -296,12 +297,6 @@ static int __kprobes valid_kprobe_addr(int template, int slot, 
		return -EINVAL;

	}



	if (slot == 1 && bundle_encoding[template][1] != L) {

		printk(KERN_WARNING "Inserting kprobes on slot #1 "

		       "is not supported\n");

		return -EINVAL;

	}



	return 0;

}
@@ -458,23 +453,49 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) 


void __kprobes arch_arm_kprobe(struct kprobe *p)

{

	unsigned long addr = (unsigned long)p->addr;

	unsigned long arm_addr = addr & ~0xFULL;

	unsigned long arm_addr;

	bundle_t *src, *dest;



	arm_addr = ((unsigned long)p->addr) & ~0xFUL;

	dest = &((kprobe_opcode_t *)arm_addr)->bundle;

	src = &p->opcode.bundle;



	flush_icache_range((unsigned long)p->ainsn.insn,

			(unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));

	memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t));

	switch (p->ainsn.slot) {

		case 0:

			dest->quad0.slot0 = src->quad0.slot0;

			break;

		case 1:

			dest->quad1.slot1_p1 = src->quad1.slot1_p1;

			break;

		case 2:

			dest->quad1.slot2 = src->quad1.slot2;

			break;

	}

	flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));

}



void __kprobes arch_disarm_kprobe(struct kprobe *p)

{

	unsigned long addr = (unsigned long)p->addr;

	unsigned long arm_addr = addr & ~0xFULL;

	unsigned long arm_addr;

	bundle_t *src, *dest;



	arm_addr = ((unsigned long)p->addr) & ~0xFUL;

	dest = &((kprobe_opcode_t *)arm_addr)->bundle;

	/* p->ainsn.insn contains the original unaltered kprobe_opcode_t */

	memcpy((char *) arm_addr, (char *) p->ainsn.insn,

					 sizeof(kprobe_opcode_t));

	src = &p->ainsn.insn->bundle;

	switch (p->ainsn.slot) {

		case 0:

			dest->quad0.slot0 = src->quad0.slot0;

			break;

		case 1:

			dest->quad1.slot1_p1 = src->quad1.slot1_p1;

			break;

		case 2:

			dest->quad1.slot2 = src->quad1.slot2;

			break;

	}

	flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));

}
@@ -807,7 +828,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	switch(val) {

	case DIE_BREAK:

		/* err is break number from ia64_bad_break() */

		if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0)

		if ((args->err >> 12) == (__IA64_BREAK_KPROBE >> 12)

			|| args->err == __IA64_BREAK_JPROBE

			|| args->err == 0)

			if (pre_kprobes_handler(args))

				ret = NOTIFY_STOP;

		break;

include/asm-ia64/break.h

+2 −2
Original line number Diff line number Diff line
@@ -12,8 +12,8 @@ 
 * OS-specific debug break numbers:

 */

#define __IA64_BREAK_KDB		0x80100

#define __IA64_BREAK_KPROBE		0x80200

#define __IA64_BREAK_JPROBE		0x80300

#define __IA64_BREAK_KPROBE		0x81000 /* .. 0x81fff */

#define __IA64_BREAK_JPROBE		0x82000



/*

 * OS-specific break numbers:

include/asm-ia64/kprobes.h

+1 −0
Original line number Diff line number Diff line
@@ -115,6 +115,7 @@ struct arch_specific_insn { 
 #define INST_FLAG_BREAK_INST			4

 	unsigned long inst_flag;

 	unsigned short target_br_reg;

	unsigned short slot;

};



extern int kprobe_exceptions_notify(struct notifier_block *self,

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