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Commit 1f7ad57b authored by Prasanna S Panchamukhi's avatar Prasanna S Panchamukhi Committed by Linus Torvalds
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[PATCH] Kprobes: prevent possible race conditions ia64 changes 



This patch contains the ia64 architecture specific changes to prevent the
possible race conditions.

Signed-off-by: default avatarPrasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bb144a85

arch/ia64/kernel/jprobes.S

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 
	/*

	 * void jprobe_break(void)

	 */

	.section .kprobes.text, "ax"

ENTRY(jprobe_break)

	break.m 0x80300

END(jprobe_break)

arch/ia64/kernel/kprobes.c

+33 −24
Original line number Diff line number Diff line
@@ -87,8 +87,10 @@ static enum instruction_type bundle_encoding[32][3] = { 
 * is IP relative instruction and update the kprobe

 * inst flag accordingly

 */

static void update_kprobe_inst_flag(uint template, uint  slot, uint major_opcode,

	unsigned long kprobe_inst, struct kprobe *p)

static void __kprobes update_kprobe_inst_flag(uint template, uint  slot,

					      uint major_opcode,

					      unsigned long kprobe_inst,

					      struct kprobe *p)

{

	p->ainsn.inst_flag = 0;

	p->ainsn.target_br_reg = 0;
@@ -126,8 +128,10 @@ static void update_kprobe_inst_flag(uint template, uint slot, uint major_opcode 
 * Returns 0 if supported

 * Returns -EINVAL if unsupported

 */

static int unsupported_inst(uint template, uint  slot, uint major_opcode,

	unsigned long kprobe_inst, struct kprobe *p)

static int __kprobes unsupported_inst(uint template, uint  slot,

				      uint major_opcode,

				      unsigned long kprobe_inst,

				      struct kprobe *p)

{

	unsigned long addr = (unsigned long)p->addr;
@@ -168,7 +172,8 @@ static int unsupported_inst(uint template, uint slot, uint major_opcode, 
 * on which we are inserting kprobe is cmp instruction

 * with ctype as unc.

 */

static uint is_cmp_ctype_unc_inst(uint template, uint slot, uint major_opcode,

static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot,

					    uint major_opcode,

					    unsigned long kprobe_inst)

{

	cmp_inst_t cmp_inst;
@@ -201,8 +206,10 @@ unsigned long kprobe_inst) 
 * In this function we override the bundle with

 * the break instruction at the given slot.

 */

static void prepare_break_inst(uint template, uint  slot, uint major_opcode,

	unsigned long kprobe_inst, struct kprobe *p)

static void __kprobes prepare_break_inst(uint template, uint  slot,

					 uint major_opcode,

					 unsigned long kprobe_inst,

					 struct kprobe *p)

{

	unsigned long break_inst = BREAK_INST;

	bundle_t *bundle = &p->ainsn.insn.bundle;
@@ -271,7 +278,8 @@ static inline int in_ivt_functions(unsigned long addr) 
		&& addr < (unsigned long)__end_ivt_text);

}



static int valid_kprobe_addr(int template, int slot, unsigned long addr)

static int __kprobes valid_kprobe_addr(int template, int slot,

				       unsigned long addr)

{

	if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {

		printk(KERN_WARNING "Attempting to insert unaligned kprobe "
@@ -323,7 +331,7 @@ static void kretprobe_trampoline(void) 
 *    - cleanup by marking the instance as unused

 *    - long jump back to the original return address

 */

int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)

int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct kretprobe_instance *ri = NULL;

	struct hlist_head *head;
@@ -381,7 +389,8 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) 
        return 1;

}



void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs)

void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,

				      struct pt_regs *regs)

{

	struct kretprobe_instance *ri;
@@ -399,7 +408,7 @@ void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) 
	}

}



int arch_prepare_kprobe(struct kprobe *p)

int __kprobes arch_prepare_kprobe(struct kprobe *p)

{

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

	unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
@@ -430,7 +439,7 @@ int arch_prepare_kprobe(struct kprobe *p) 
	return 0;

}



void arch_arm_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;
@@ -439,7 +448,7 @@ void arch_arm_kprobe(struct kprobe *p) 
	flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));

}



void arch_disarm_kprobe(struct kprobe *p)

void __kprobes arch_disarm_kprobe(struct kprobe *p)

{

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

	unsigned long arm_addr = addr & ~0xFULL;
@@ -449,7 +458,7 @@ void arch_disarm_kprobe(struct kprobe *p) 
	flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));

}



void arch_remove_kprobe(struct kprobe *p)

void __kprobes arch_remove_kprobe(struct kprobe *p)

{

}
@@ -461,7 +470,7 @@ void arch_remove_kprobe(struct kprobe *p) 
 * to original stack address, handle the case where we need to fixup the

 * relative IP address and/or fixup branch register.

 */

static void resume_execution(struct kprobe *p, struct pt_regs *regs)

static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)

{

  	unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL;

  	unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
@@ -528,7 +537,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs) 
  	ia64_psr(regs)->ss = 0;

}



static void prepare_ss(struct kprobe *p, struct pt_regs *regs)

static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)

{

	unsigned long bundle_addr = (unsigned long) &p->opcode.bundle;

	unsigned long slot = (unsigned long)p->addr & 0xf;
@@ -545,7 +554,7 @@ static void prepare_ss(struct kprobe *p, struct pt_regs *regs) 
	ia64_psr(regs)->ss = 1;

}



static int pre_kprobes_handler(struct die_args *args)

static int __kprobes pre_kprobes_handler(struct die_args *args)

{

	struct kprobe *p;

	int ret = 0;
@@ -616,7 +625,7 @@ static int pre_kprobes_handler(struct die_args *args) 
	return ret;

}



static int post_kprobes_handler(struct pt_regs *regs)

static int __kprobes post_kprobes_handler(struct pt_regs *regs)

{

	if (!kprobe_running())

		return 0;
@@ -641,7 +650,7 @@ static int post_kprobes_handler(struct pt_regs *regs) 
	return 1;

}



static int kprobes_fault_handler(struct pt_regs *regs, int trapnr)

static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)

{

	if (!kprobe_running())

		return 0;
@@ -659,8 +668,8 @@ static int kprobes_fault_handler(struct pt_regs *regs, int trapnr) 
	return 0;

}



int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,

			     void *data)

int __kprobes kprobe_exceptions_notify(struct notifier_block *self,

				       unsigned long val, void *data)

{

	struct die_args *args = (struct die_args *)data;

	switch(val) {
@@ -681,7 +690,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, 
	return NOTIFY_DONE;

}



int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct jprobe *jp = container_of(p, struct jprobe, kp);

	unsigned long addr = ((struct fnptr *)(jp->entry))->ip;
@@ -703,7 +712,7 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) 
	return 1;

}



int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)

int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)

{

	*regs = jprobe_saved_regs;

	return 1;

arch/ia64/kernel/traps.c

+3 −2
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/vt_kern.h>		/* For unblank_screen() */

#include <linux/module.h>       /* for EXPORT_SYMBOL */

#include <linux/hardirq.h>

#include <linux/kprobes.h>



#include <asm/fpswa.h>

#include <asm/ia32.h>
@@ -122,7 +123,7 @@ die_if_kernel (char *str, struct pt_regs *regs, long err) 
}



void

ia64_bad_break (unsigned long break_num, struct pt_regs *regs)

__kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)

{

	siginfo_t siginfo;

	int sig, code;
@@ -444,7 +445,7 @@ ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3, 
	return rv;

}



void

void __kprobes

ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,

	    unsigned long iim, unsigned long itir, long arg5, long arg6,

	    long arg7, struct pt_regs regs)

arch/ia64/kernel/vmlinux.lds.S

+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ SECTIONS 
	*(.text)

	SCHED_TEXT

	LOCK_TEXT

	KPROBES_TEXT

	*(.gnu.linkonce.t*)

    }

  .text2 : AT(ADDR(.text2) - LOAD_OFFSET)

arch/ia64/lib/flush.S

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
	 *

	 *	Note: "in0" and "in1" are preserved for debugging purposes.

	 */

	.section .kprobes.text,"ax"

GLOBAL_ENTRY(flush_icache_range)



	.prologue