x86: use wrmsrl in kprobes.c, step.c (f13bd3e7) · Commits · 戴 / test

Where x86_32 passed zero in the high 32 bits, use wrmsrl which will zero extend for us. This allows ifdefs for 32/64 bit to be eliminated. Eliminate ifdef in step.c. Similar cleanup was done when unifying kprobes_32|64.c and wrmsr() was chosen there over wrmsrl(). This patch changes these to wrmsrl. Signed-off-by:

Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by:

Ingo Molnar <mingo@elte.hu> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/kprobes.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -410,13 +410,13 @@ static void __kprobes set_current_kprobe(struct kprobe p, struct pt_regs regs,
		static void __kprobes clear_btf(void)
		{
		if (test_thread_flag(TIF_DEBUGCTLMSR))
		wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
		wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
		}

		static void __kprobes restore_btf(void)
		{
		if (test_thread_flag(TIF_DEBUGCTLMSR))
		wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
		wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
		}

		static void __kprobes prepare_singlestep(struct kprobe p, struct pt_regs regs)

arch/x86/kernel/step.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -229,11 +229,7 @@ static void write_debugctlmsr(struct task_struct *child, unsigned long val)
		if (child != current)
		return;

		#ifdef CONFIG_X86_64
		wrmsrl(MSR_IA32_DEBUGCTLMSR, val);
		#else
		wrmsr(MSR_IA32_DEBUGCTLMSR, val, 0);
		#endif
		}

		/*

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