From 3d97ae5b958855ac007b6f56a0f94ab8ade09e9e Mon Sep 17 00:00:00 2001 From: Prasanna S Panchamukhi Date: Tue, 6 Sep 2005 15:19:27 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/entry.S | 13 ++++++++----- arch/i386/kernel/kprobes.c | 29 +++++++++++++++-------------- arch/i386/kernel/traps.c | 12 +++++++----- arch/i386/kernel/vmlinux.lds.S | 1 + arch/i386/mm/fault.c | 4 +++- 5 files changed, 34 insertions(+), 25 deletions(-) diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index abb909793efc..3aad03839660 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -507,7 +507,7 @@ label: \ 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 @@ debug_stack_correct: 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 @@ nmi_16bit_stack: .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 @@ ENTRY(stack_segment) 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 a6d8c45961d3..7fb5a6f4a563 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -62,32 +62,32 @@ static inline int is_IF_modifier(kprobe_opcode_t opcode) 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 @@ static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) 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 @@ 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. */ -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 @@ 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; @@ -338,7 +339,7 @@ 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 *)®s->esp; unsigned long next_eip = 0; @@ -444,8 +445,8 @@ 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; switch (val) { @@ -473,7 +474,7 @@ 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; @@ -495,7 +496,7 @@ 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 (" xchgl %%ebx,%%esp \n" @@ -506,7 +507,7 @@ void jprobe_return(void) (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 029bf94cda7d..09a58cb6daa7 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -363,8 +363,9 @@ static inline void die_if_kernel(const char * str, struct pt_regs * regs, long e 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(12, SIGBUS, "stack segment", stack_segment) 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 @@ void unset_nmi_callback(void) 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 @@ fastcall void do_int3(struct pt_regs *regs, long error_code) * 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 761972f8cb6c..13b9c62cbbb4 100644 --- a/arch/i386/kernel/vmlinux.lds.S +++ b/arch/i386/kernel/vmlinux.lds.S @@ -22,6 +22,7 @@ SECTIONS *(.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 411b8500ad1b..9edd4485b91e 100644 --- a/arch/i386/mm/fault.c +++ b/arch/i386/mm/fault.c @@ -21,6 +21,7 @@ #include /* For unblank_screen() */ #include #include +#include #include #include @@ -223,7 +224,8 @@ fastcall void do_invalid_op(struct pt_regs *, unsigned long); * 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; -- 2.30.2