Commit 0f2fbdcb authored by Prasanna S Panchamukhi's avatar Prasanna S Panchamukhi Committed by Linus Torvalds
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[PATCH] kprobes: prevent possible race conditions x86_64 changes



This patch contains the x86_64 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 3d97ae5b
...@@ -784,8 +784,9 @@ ENTRY(execve) ...@@ -784,8 +784,9 @@ ENTRY(execve)
ret ret
CFI_ENDPROC CFI_ENDPROC
ENTRY(page_fault) KPROBE_ENTRY(page_fault)
errorentry do_page_fault errorentry do_page_fault
.previous .text
ENTRY(coprocessor_error) ENTRY(coprocessor_error)
zeroentry do_coprocessor_error zeroentry do_coprocessor_error
...@@ -797,13 +798,14 @@ ENTRY(device_not_available) ...@@ -797,13 +798,14 @@ ENTRY(device_not_available)
zeroentry math_state_restore zeroentry math_state_restore
/* runs on exception stack */ /* runs on exception stack */
ENTRY(debug) KPROBE_ENTRY(debug)
CFI_STARTPROC CFI_STARTPROC
pushq $0 pushq $0
CFI_ADJUST_CFA_OFFSET 8 CFI_ADJUST_CFA_OFFSET 8
paranoidentry do_debug paranoidentry do_debug
jmp paranoid_exit jmp paranoid_exit
CFI_ENDPROC CFI_ENDPROC
.previous .text
/* runs on exception stack */ /* runs on exception stack */
ENTRY(nmi) ENTRY(nmi)
...@@ -854,8 +856,9 @@ paranoid_schedule: ...@@ -854,8 +856,9 @@ paranoid_schedule:
jmp paranoid_userspace jmp paranoid_userspace
CFI_ENDPROC CFI_ENDPROC
ENTRY(int3) KPROBE_ENTRY(int3)
zeroentry do_int3 zeroentry do_int3
.previous .text
ENTRY(overflow) ENTRY(overflow)
zeroentry do_overflow zeroentry do_overflow
...@@ -892,8 +895,9 @@ ENTRY(stack_segment) ...@@ -892,8 +895,9 @@ ENTRY(stack_segment)
jmp paranoid_exit jmp paranoid_exit
CFI_ENDPROC CFI_ENDPROC
ENTRY(general_protection) KPROBE_ENTRY(general_protection)
errorentry do_general_protection errorentry do_general_protection
.previous .text
ENTRY(alignment_check) ENTRY(alignment_check)
errorentry do_alignment_check errorentry do_alignment_check
......
...@@ -74,7 +74,7 @@ static inline int is_IF_modifier(kprobe_opcode_t *insn) ...@@ -74,7 +74,7 @@ static inline int is_IF_modifier(kprobe_opcode_t *insn)
return 0; 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. */ /* insn: must be on special executable page on x86_64. */
up(&kprobe_mutex); up(&kprobe_mutex);
...@@ -189,7 +189,7 @@ static inline s32 *is_riprel(u8 *insn) ...@@ -189,7 +189,7 @@ static inline s32 *is_riprel(u8 *insn)
return NULL; return NULL;
} }
void arch_copy_kprobe(struct kprobe *p) void __kprobes arch_copy_kprobe(struct kprobe *p)
{ {
s32 *ripdisp; s32 *ripdisp;
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE); memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
...@@ -215,21 +215,21 @@ void arch_copy_kprobe(struct kprobe *p) ...@@ -215,21 +215,21 @@ void arch_copy_kprobe(struct kprobe *p)
p->opcode = *p->addr; p->opcode = *p->addr;
} }
void arch_arm_kprobe(struct kprobe *p) void __kprobes arch_arm_kprobe(struct kprobe *p)
{ {
*p->addr = BREAKPOINT_INSTRUCTION; *p->addr = BREAKPOINT_INSTRUCTION;
flush_icache_range((unsigned long) p->addr, flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t)); (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; *p->addr = p->opcode;
flush_icache_range((unsigned long) p->addr, flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t)); (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); up(&kprobe_mutex);
free_insn_slot(p->ainsn.insn); free_insn_slot(p->ainsn.insn);
...@@ -261,7 +261,7 @@ static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs) ...@@ -261,7 +261,7 @@ static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs)
kprobe_saved_rflags &= ~IF_MASK; 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 |= TF_MASK;
regs->eflags &= ~IF_MASK; regs->eflags &= ~IF_MASK;
...@@ -272,7 +272,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) ...@@ -272,7 +272,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
regs->rip = (unsigned long)p->ainsn.insn; 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; unsigned long *sara = (unsigned long *)regs->rsp;
struct kretprobe_instance *ri; struct kretprobe_instance *ri;
...@@ -295,7 +296,7 @@ void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) ...@@ -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 * Interrupts are disabled on entry as trap3 is an interrupt gate and they
* remain disabled thorough out this function. * remain disabled thorough out this function.
*/ */
int kprobe_handler(struct pt_regs *regs) int __kprobes kprobe_handler(struct pt_regs *regs)
{ {
struct kprobe *p; struct kprobe *p;
int ret = 0; int ret = 0;
...@@ -399,7 +400,7 @@ int kprobe_handler(struct pt_regs *regs) ...@@ -399,7 +400,7 @@ int kprobe_handler(struct pt_regs *regs)
/* /*
* Called when we hit the probe point at kretprobe_trampoline * 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 kretprobe_instance *ri = NULL;
struct hlist_head *head; struct hlist_head *head;
...@@ -478,7 +479,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) ...@@ -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. * that is atop the stack is the address following the copied instruction.
* We need to make it the address following the original 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 *tos = (unsigned long *)regs->rsp;
unsigned long next_rip = 0; unsigned long next_rip = 0;
...@@ -536,7 +537,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs) ...@@ -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 * Interrupts are disabled on entry as trap1 is an interrupt gate and they
* remain disabled thoroughout this function. And we hold kprobe lock. * 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()) if (!kprobe_running())
return 0; return 0;
...@@ -571,7 +572,7 @@ int post_kprobe_handler(struct pt_regs *regs) ...@@ -571,7 +572,7 @@ int post_kprobe_handler(struct pt_regs *regs)
} }
/* Interrupts disabled, kprobe_lock held. */ /* 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 if (current_kprobe->fault_handler
&& current_kprobe->fault_handler(current_kprobe, regs, trapnr)) && current_kprobe->fault_handler(current_kprobe, regs, trapnr))
...@@ -590,8 +591,8 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) ...@@ -590,8 +591,8 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
/* /*
* Wrapper routine for handling exceptions. * Wrapper routine for handling exceptions.
*/ */
int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
void *data) unsigned long val, void *data)
{ {
struct die_args *args = (struct die_args *)data; struct die_args *args = (struct die_args *)data;
switch (val) { switch (val) {
...@@ -619,7 +620,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, ...@@ -619,7 +620,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
return NOTIFY_DONE; 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); struct jprobe *jp = container_of(p, struct jprobe, kp);
unsigned long addr; unsigned long addr;
...@@ -640,7 +641,7 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) ...@@ -640,7 +641,7 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
return 1; return 1;
} }
void jprobe_return(void) void __kprobes jprobe_return(void)
{ {
preempt_enable_no_resched(); preempt_enable_no_resched();
asm volatile (" xchg %%rbx,%%rsp \n" asm volatile (" xchg %%rbx,%%rsp \n"
...@@ -651,7 +652,7 @@ void jprobe_return(void) ...@@ -651,7 +652,7 @@ void jprobe_return(void)
(jprobe_saved_rsp):"memory"); (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); u8 *addr = (u8 *) (regs->rip - 1);
unsigned long stack_addr = (unsigned long)jprobe_saved_rsp; unsigned long stack_addr = (unsigned long)jprobe_saved_rsp;
......
...@@ -29,6 +29,7 @@ ...@@ -29,6 +29,7 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/moduleparam.h> #include <linux/moduleparam.h>
#include <linux/nmi.h> #include <linux/nmi.h>
#include <linux/kprobes.h>
#include <asm/system.h> #include <asm/system.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -419,8 +420,9 @@ void die_nmi(char *str, struct pt_regs *regs) ...@@ -419,8 +420,9 @@ void die_nmi(char *str, struct pt_regs *regs)
do_exit(SIGSEGV); do_exit(SIGSEGV);
} }
static void do_trap(int trapnr, int signr, char *str, static void __kprobes do_trap(int trapnr, int signr, char *str,
struct pt_regs * regs, long error_code, siginfo_t *info) struct pt_regs * regs, long error_code,
siginfo_t *info)
{ {
conditional_sti(regs); conditional_sti(regs);
...@@ -504,7 +506,8 @@ DO_ERROR(18, SIGSEGV, "reserved", reserved) ...@@ -504,7 +506,8 @@ DO_ERROR(18, SIGSEGV, "reserved", reserved)
DO_ERROR(12, SIGBUS, "stack segment", stack_segment) DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
DO_ERROR( 8, SIGSEGV, "double fault", double_fault) 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); conditional_sti(regs);
...@@ -622,7 +625,7 @@ asmlinkage void default_do_nmi(struct pt_regs *regs) ...@@ -622,7 +625,7 @@ asmlinkage void default_do_nmi(struct pt_regs *regs)
io_check_error(reason, 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) { if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
return; return;
...@@ -653,7 +656,8 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs) ...@@ -653,7 +656,8 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
} }
/* runs on IST stack. */ /* 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; unsigned long condition;
struct task_struct *tsk = current; struct task_struct *tsk = current;
......
...@@ -21,6 +21,7 @@ SECTIONS ...@@ -21,6 +21,7 @@ SECTIONS
*(.text) *(.text)
SCHED_TEXT SCHED_TEXT
LOCK_TEXT LOCK_TEXT
KPROBES_TEXT
*(.fixup) *(.fixup)
*(.gnu.warning) *(.gnu.warning)
} = 0x9090 } = 0x9090
......
...@@ -23,6 +23,7 @@ ...@@ -23,6 +23,7 @@
#include <linux/vt_kern.h> /* For unblank_screen() */ #include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/compiler.h> #include <linux/compiler.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/kprobes.h>
#include <asm/system.h> #include <asm/system.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -294,7 +295,8 @@ int exception_trace = 1; ...@@ -294,7 +295,8 @@ int exception_trace = 1;
* bit 2 == 0 means kernel, 1 means user-mode * bit 2 == 0 means kernel, 1 means user-mode
* bit 3 == 1 means fault was an instruction fetch * 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 task_struct *tsk;
struct mm_struct *mm; struct mm_struct *mm;
......
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