Commit bb144a85 authored by Prasanna S Panchamukhi's avatar Prasanna S Panchamukhi Committed by Linus Torvalds
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[PATCH] Kprobes: prevent possible race conditions ppc64 changes



This patch contains the ppc64 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 0f2fbdcb
......@@ -44,7 +44,7 @@ static struct kprobe *kprobe_prev;
static unsigned long kprobe_status_prev, kprobe_saved_msr_prev;
static struct pt_regs jprobe_saved_regs;
int arch_prepare_kprobe(struct kprobe *p)
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
kprobe_opcode_t insn = *p->addr;
......@@ -68,27 +68,27 @@ int arch_prepare_kprobe(struct kprobe *p)
return ret;
}
void arch_copy_kprobe(struct kprobe *p)
void __kprobes arch_copy_kprobe(struct kprobe *p)
{
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
p->opcode = *p->addr;
}
void arch_arm_kprobe(struct kprobe *p)
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
*p->addr = BREAKPOINT_INSTRUCTION;
flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t));
}
void arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
*p->addr = p->opcode;
flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t));
}
void arch_remove_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
up(&kprobe_mutex);
free_insn_slot(p->ainsn.insn);
......@@ -122,7 +122,8 @@ static inline void restore_previous_kprobe(void)
kprobe_saved_msr = kprobe_saved_msr_prev;
}
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;
......@@ -244,7 +245,7 @@ void kretprobe_trampoline_holder(void)
/*
* Called when the probe at kretprobe trampoline is hit
*/
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;
......@@ -308,7 +309,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* single-stepped a copy of the instruction. The address of this
* copy is p->ainsn.insn.
*/
static void resume_execution(struct kprobe *p, struct pt_regs *regs)
static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
{
int ret;
unsigned int insn = *p->ainsn.insn;
......@@ -373,8 +374,8 @@ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
/*
* Wrapper routine to for handling exceptions.
*/
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;
int ret = NOTIFY_DONE;
......@@ -406,7 +407,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
return ret;
}
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);
......@@ -419,16 +420,16 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
return 1;
}
void jprobe_return(void)
void __kprobes jprobe_return(void)
{
asm volatile("trap" ::: "memory");
}
void jprobe_return_end(void)
void __kprobes jprobe_return_end(void)
{
};
int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
/*
* FIXME - we should ideally be validating that we got here 'cos
......
......@@ -183,7 +183,7 @@ PPC64_CACHES:
* flush all bytes from start through stop-1 inclusive
*/
_GLOBAL(__flush_icache_range)
_KPROBE(__flush_icache_range)
/*
* Flush the data cache to memory
......@@ -223,7 +223,7 @@ _GLOBAL(__flush_icache_range)
bdnz 2b
isync
blr
.previous .text
/*
* Like above, but only do the D-cache.
*
......
......@@ -30,6 +30,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/kprobes.h>
#include <asm/kdebug.h>
#include <asm/pgtable.h>
......@@ -220,7 +221,7 @@ void instruction_breakpoint_exception(struct pt_regs *regs)
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
}
void single_step_exception(struct pt_regs *regs)
void __kprobes single_step_exception(struct pt_regs *regs)
{
regs->msr &= ~MSR_SE; /* Turn off 'trace' bit */
......@@ -398,7 +399,7 @@ check_bug_trap(struct pt_regs *regs)
return 0;
}
void program_check_exception(struct pt_regs *regs)
void __kprobes program_check_exception(struct pt_regs *regs)
{
if (debugger_fault_handler(regs))
return;
......
......@@ -15,6 +15,7 @@ SECTIONS
*(.text .text.*)
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
*(.fixup)
. = ALIGN(4096);
_etext = .;
......
......@@ -29,6 +29,7 @@
#include <linux/interrupt.h>
#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <asm/page.h>
#include <asm/pgtable.h>
......@@ -84,8 +85,8 @@ static int store_updates_sp(struct pt_regs *regs)
* The return value is 0 if the fault was handled, or the signal
* number if this is a kernel fault that can't be handled here.
*/
int do_page_fault(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
......
......@@ -311,6 +311,20 @@ name: \
.type GLUE(.,name),@function; \
GLUE(.,name):
#define _KPROBE(name) \
.section ".kprobes.text","a"; \
.align 2 ; \
.globl name; \
.globl GLUE(.,name); \
.section ".opd","aw"; \
name: \
.quad GLUE(.,name); \
.quad .TOC.@tocbase; \
.quad 0; \
.previous; \
.type GLUE(.,name),@function; \
GLUE(.,name):
#define _STATIC(name) \
.section ".text"; \
.align 2 ; \
......
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