Commit fab94075 authored Jan 27, 2019 by Borislav Petkov

x86/hw_breakpoints, kprobes: Remove kprobes ifdeffery



Remove the ifdeffery in the breakpoint parsing arch_build_bp_info() by
adding a within_kprobe_blacklist() stub for the !CONFIG_KPROBES case.

It is returning true when kprobes are not enabled to mean that any
address is within the kprobes blacklist on such kernels and thus not
allow kernel breakpoints on non-kprobes kernels.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190127131237.4557-1-bp@alien8.de

parent 0a278662

arch/x86/kernel/hw_breakpoint.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -261,12 +261,8 @@ static int arch_build_bp_info(struct perf_event *bp,
		* allow kernel breakpoints at all.
		*/
		if (attr->bp_addr >= TASK_SIZE_MAX) {
		#ifdef CONFIG_KPROBES
		if (within_kprobe_blacklist(attr->bp_addr))
		return -EINVAL;
		#else
		return -EINVAL;
		#endif
		}

		hw->type = X86_BREAKPOINT_EXECUTE;

include/linux/kprobes.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -442,6 +442,11 @@ static inline int enable_kprobe(struct kprobe *kp)
		{
		return -ENOSYS;
		}

		static inline bool within_kprobe_blacklist(unsigned long addr)
		{
		return true;
		}
		#endif /* CONFIG_KPROBES */
		static inline int disable_kretprobe(struct kretprobe *rp)
		{

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