[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: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 096d470..be51dbe 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -784,8 +784,9 @@
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 @@
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 @@
jmp paranoid_userspace
CFI_ENDPROC
-ENTRY(int3)
+KPROBE_ENTRY(int3)
zeroentry do_int3
+ .previous .text
ENTRY(overflow)
zeroentry do_overflow
@@ -892,8 +895,9 @@
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
diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c
index 5c6dc70..c21ccea 100644
--- a/arch/x86_64/kernel/kprobes.c
+++ b/arch/x86_64/kernel/kprobes.c
@@ -74,7 +74,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
* 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 @@
/*
* 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 @@
* 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 @@
* 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 @@
}
/* 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 @@
/*
* 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 @@
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 @@
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 @@
(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;
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 6ead433..f238d60 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -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 @@
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(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 @@
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 @@
}
/* 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;
diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S
index 2a94f9b..d4abb07 100644
--- a/arch/x86_64/kernel/vmlinux.lds.S
+++ b/arch/x86_64/kernel/vmlinux.lds.S
@@ -21,6 +21,7 @@
*(.text)
SCHED_TEXT
LOCK_TEXT
+ KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
} = 0x9090
diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index ca914c3..816732d 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -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 @@
* 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;
