[PATCH] kprobes: prevent possible race conditions i386 changes
This patch contains the i386 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/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index abb9097..3aad038 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -507,7 +507,7 @@
pushl $__KERNEL_CS; \
pushl $sysenter_past_esp
-ENTRY(debug)
+KPROBE_ENTRY(debug)
cmpl $sysenter_entry,(%esp)
jne debug_stack_correct
FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
@@ -518,7 +518,7 @@
movl %esp,%eax # pt_regs pointer
call do_debug
jmp ret_from_exception
-
+ .previous .text
/*
* NMI is doubly nasty. It can happen _while_ we're handling
* a debug fault, and the debug fault hasn't yet been able to
@@ -591,13 +591,14 @@
.long 1b,iret_exc
.previous
-ENTRY(int3)
+KPROBE_ENTRY(int3)
pushl $-1 # mark this as an int
SAVE_ALL
xorl %edx,%edx # zero error code
movl %esp,%eax # pt_regs pointer
call do_int3
jmp ret_from_exception
+ .previous .text
ENTRY(overflow)
pushl $0
@@ -631,17 +632,19 @@
pushl $do_stack_segment
jmp error_code
-ENTRY(general_protection)
+KPROBE_ENTRY(general_protection)
pushl $do_general_protection
jmp error_code
+ .previous .text
ENTRY(alignment_check)
pushl $do_alignment_check
jmp error_code
-ENTRY(page_fault)
+KPROBE_ENTRY(page_fault)
pushl $do_page_fault
jmp error_code
+ .previous .text
#ifdef CONFIG_X86_MCE
ENTRY(machine_check)
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index a6d8c45..7fb5a6f 100644
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -62,32 +62,32 @@
return 0;
}
-int arch_prepare_kprobe(struct kprobe *p)
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
return 0;
}
-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)
{
}
@@ -127,7 +127,8 @@
regs->eip = (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 *)®s->esp;
struct kretprobe_instance *ri;
@@ -150,7 +151,7 @@
* Interrupts are disabled on entry as trap3 is an interrupt gate and they
* remain disabled thorough out this function.
*/
-static int kprobe_handler(struct pt_regs *regs)
+static int __kprobes kprobe_handler(struct pt_regs *regs)
{
struct kprobe *p;
int ret = 0;
@@ -259,7 +260,7 @@
/*
* 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;
@@ -338,7 +339,7 @@
* 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 *)®s->esp;
unsigned long next_eip = 0;
@@ -444,8 +445,8 @@
/*
* 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;
switch (val) {
@@ -473,7 +474,7 @@
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;
@@ -495,7 +496,7 @@
return 1;
}
-void jprobe_return(void)
+void __kprobes jprobe_return(void)
{
preempt_enable_no_resched();
asm volatile (" xchgl %%ebx,%%esp \n"
@@ -506,7 +507,7 @@
(jprobe_saved_esp):"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->eip - 1);
unsigned long stack_addr = (unsigned long)jprobe_saved_esp;
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 029bf94..09a58cb 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -363,8 +363,9 @@
die(str, regs, err);
}
-static void do_trap(int trapnr, int signr, char *str, int vm86,
- struct pt_regs * regs, long error_code, siginfo_t *info)
+static void __kprobes do_trap(int trapnr, int signr, char *str, int vm86,
+ struct pt_regs * regs, long error_code,
+ siginfo_t *info)
{
struct task_struct *tsk = current;
tsk->thread.error_code = error_code;
@@ -460,7 +461,8 @@
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0)
-fastcall void do_general_protection(struct pt_regs * regs, long error_code)
+fastcall void __kprobes do_general_protection(struct pt_regs * regs,
+ long error_code)
{
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
@@ -676,7 +678,7 @@
EXPORT_SYMBOL_GPL(unset_nmi_callback);
#ifdef CONFIG_KPROBES
-fastcall void do_int3(struct pt_regs *regs, long error_code)
+fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
@@ -710,7 +712,7 @@
* find every occurrence of the TF bit that could be saved away even
* by user code)
*/
-fastcall void do_debug(struct pt_regs * regs, long error_code)
+fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
{
unsigned int condition;
struct task_struct *tsk = current;
diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
index 761972f..13b9c62 100644
--- a/arch/i386/kernel/vmlinux.lds.S
+++ b/arch/i386/kernel/vmlinux.lds.S
@@ -22,6 +22,7 @@
*(.text)
SCHED_TEXT
LOCK_TEXT
+ KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
} = 0x9090
diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index 411b850..9edd448 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -21,6 +21,7 @@
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/highmem.h>
#include <linux/module.h>
+#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -223,7 +224,8 @@
* bit 1 == 0 means read, 1 means write
* bit 2 == 0 means kernel, 1 means user-mode
*/
-fastcall void do_page_fault(struct pt_regs *regs, unsigned long error_code)
+fastcall void __kprobes do_page_fault(struct pt_regs *regs,
+ unsigned long error_code)
{
struct task_struct *tsk;
struct mm_struct *mm;