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[PATCH] kprobes: prevent possible race conditions x86_64 changes

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This patch contains the x86_64 architecture specific changes to prevent the
possible race conditions.

Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Prasanna S Panchamukhi 2005-09-06 15:19:28 -07:00 committed by Linus Torvalds
parent 3d97ae5b95
commit 0f2fbdcbb0
5 changed files with 39 additions and 27 deletions
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12
arch/x86_64/kernel/entry.S
View File

@ -784,8 +784,9 @@ ENTRY(execve)
ret
CFI_ENDPROC
ENTRY(page_fault)
KPROBE_ENTRY(page_fault)
errorentry do_page_fault
.previous .text
ENTRY(coprocessor_error)
zeroentry do_coprocessor_error
@ -797,13 +798,14 @@ ENTRY(device_not_available)
zeroentry math_state_restore
/* runs on exception stack */
ENTRY(debug)
KPROBE_ENTRY(debug)
CFI_STARTPROC
pushq $0
CFI_ADJUST_CFA_OFFSET 8
paranoidentry do_debug
jmp paranoid_exit
CFI_ENDPROC
.previous .text
/* runs on exception stack */
ENTRY(nmi)
@ -854,8 +856,9 @@ paranoid_schedule:
jmp paranoid_userspace
CFI_ENDPROC
ENTRY(int3)
KPROBE_ENTRY(int3)
zeroentry do_int3
.previous .text
ENTRY(overflow)
zeroentry do_overflow
@ -892,8 +895,9 @@ ENTRY(stack_segment)
jmp paranoid_exit
CFI_ENDPROC
ENTRY(general_protection)
KPROBE_ENTRY(general_protection)
errorentry do_general_protection
.previous .text
ENTRY(alignment_check)
errorentry do_alignment_check

35
arch/x86_64/kernel/kprobes.c
View File

@ -74,7 +74,7 @@ static inline int is_IF_modifier(kprobe_opcode_t *insn)
return 0;
}
int arch_prepare_kprobe(struct kprobe *p)
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
/* insn: must be on special executable page on x86_64. */
up(&kprobe_mutex);
@ -189,7 +189,7 @@ static inline s32 *is_riprel(u8 *insn)
return NULL;
}
void arch_copy_kprobe(struct kprobe *p)
void __kprobes arch_copy_kprobe(struct kprobe *p)
{
s32 *ripdisp;
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
@ -215,21 +215,21 @@ void arch_copy_kprobe(struct kprobe *p)
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);
@ -261,7 +261,7 @@ static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs)
kprobe_saved_rflags &= ~IF_MASK;
}
static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
regs->eflags |= TF_MASK;
regs->eflags &= ~IF_MASK;
@ -272,7 +272,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
regs->rip = (unsigned long)p->ainsn.insn;
}
void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs)
void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
{
unsigned long *sara = (unsigned long *)regs->rsp;
struct kretprobe_instance *ri;
@ -295,7 +296,7 @@ void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs)
* Interrupts are disabled on entry as trap3 is an interrupt gate and they
* remain disabled thorough out this function.
*/
int kprobe_handler(struct pt_regs *regs)
int __kprobes kprobe_handler(struct pt_regs *regs)
{
struct kprobe *p;
int ret = 0;
@ -399,7 +400,7 @@ no_kprobe:
/*
* Called when we hit the probe point at kretprobe_trampoline
*/
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;
@ -478,7 +479,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* that is atop the stack is the address following the copied instruction.
* We need to make it the address following the original instruction.
*/
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 *tos = (unsigned long *)regs->rsp;
unsigned long next_rip = 0;
@ -536,7 +537,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs)
* Interrupts are disabled on entry as trap1 is an interrupt gate and they
* remain disabled thoroughout this function. And we hold kprobe lock.
*/
int post_kprobe_handler(struct pt_regs *regs)
int __kprobes post_kprobe_handler(struct pt_regs *regs)
{
if (!kprobe_running())
return 0;
@ -571,7 +572,7 @@ out:
}
/* Interrupts disabled, kprobe_lock held. */
int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
if (current_kprobe->fault_handler
&& current_kprobe->fault_handler(current_kprobe, regs, trapnr))
@ -590,8 +591,8 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
/*
* Wrapper routine 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;
switch (val) {
@ -619,7 +620,7 @@ 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;
@ -640,7 +641,7 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
return 1;
}
void jprobe_return(void)
void __kprobes jprobe_return(void)
{
preempt_enable_no_resched();
asm volatile (" xchg %%rbx,%%rsp \n"
@ -651,7 +652,7 @@ void jprobe_return(void)
(jprobe_saved_rsp):"memory");
}
int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
u8 *addr = (u8 *) (regs->rip - 1);
unsigned long stack_addr = (unsigned long)jprobe_saved_rsp;

14
arch/x86_64/kernel/traps.c
View File

@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/nmi.h>
#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@ -419,8 +420,9 @@ void die_nmi(char *str, struct pt_regs *regs)
do_exit(SIGSEGV);
}
static void do_trap(int trapnr, int signr, char *str,
struct pt_regs * regs, long error_code, siginfo_t *info)
static void __kprobes do_trap(int trapnr, int signr, char *str,
struct pt_regs * regs, long error_code,
siginfo_t *info)
{
conditional_sti(regs);
@ -504,7 +506,8 @@ DO_ERROR(18, SIGSEGV, "reserved", reserved)
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
long error_code)
{
conditional_sti(regs);
@ -622,7 +625,7 @@ asmlinkage void default_do_nmi(struct pt_regs *regs)
io_check_error(reason, regs);
}
asmlinkage void do_int3(struct pt_regs * regs, long error_code)
asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
{
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
return;
@ -653,7 +656,8 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
}
/* runs on IST stack. */
asmlinkage void do_debug(struct pt_regs * regs, unsigned long error_code)
asmlinkage void __kprobes do_debug(struct pt_regs * regs,
unsigned long error_code)
{
unsigned long condition;
struct task_struct *tsk = current;

1
arch/x86_64/kernel/vmlinux.lds.S
View File

@ -21,6 +21,7 @@ SECTIONS
*(.text)
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
} = 0x9090

4
arch/x86_64/mm/fault.c
View File

@ -23,6 +23,7 @@
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@ -294,7 +295,8 @@ int exception_trace = 1;
* bit 2 == 0 means kernel, 1 means user-mode
* bit 3 == 1 means fault was an instruction fetch
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
unsigned long error_code)
{
struct task_struct *tsk;
struct mm_struct *mm;