[PATCH] kprobes: prevent possible race conditions x86_64 changes (0f2fbdcb) · Commits · e / devices / android_kernel_fairphone_FP5

arch/x86_64/kernel/entry.S

+8 −4

Original line number	Original line	Diff line number	Diff line
	@@ -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)
	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:
	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)
	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

arch/x86_64/kernel/kprobes.c

+18 −17

Original line number	Original line	Diff line number	Diff line
	@@ -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)
	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)
	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)
	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)
	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)
	* 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)
	/*		/*
	* 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)
	* 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)
	* 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)
	}		}

	/* 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)
	/*		/*
	* 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,
	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)
	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)
	(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;

arch/x86_64/kernel/traps.c

+9 −5

Original line number	Original line	Diff line number	Diff line
	@@ -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)
	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)
	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)
	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)
	}		}

	/* 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;

arch/x86_64/kernel/vmlinux.lds.S

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -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

arch/x86_64/mm/fault.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -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;
	* 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;