ARM: 6355/1: hw-breakpoint: add mechanism for hooking into prefetch aborts (3a4b5dca) · Commits · 戴 / test

On ARM processors with hardware breakpoint and watchpoint support, triggering these events results in a debug exception. These manifest as prefetch and data aborts respectively. arch/arm/mm/fault.c already provides hook_fault_code for hooking into data aborts dependent on the DFSR. This patch adds a new function, hook_ifault_code for hooking into prefetch aborts in the same manner. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: S. Karthikeyan <informkarthik@gmail.com> Signed-off-by:

Will Deacon <will.deacon@arm.com> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/system.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -85,6 +85,10 @@ void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
		struct pt_regs *),
		int sig, int code, const char *name);

		void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
		struct pt_regs *),
		int sig, int code, const char *name);

		#define xchg(ptr,x) \
		((__typeof__((ptr)))__xchg((unsigned long)(x),(ptr),sizeof((ptr))))

arch/arm/mm/fault.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -581,6 +581,19 @@ static struct fsr_info ifsr_info[] = {
		{ do_bad, SIGBUS, 0, "unknown 31" },
		};

		void __init
		hook_ifault_code(int nr, int (fn)(unsigned long, unsigned int, struct pt_regs ),
		int sig, int code, const char *name)
		{
		if (nr < 0 \|\| nr >= ARRAY_SIZE(ifsr_info))
		BUG();

		ifsr_info[nr].fn = fn;
		ifsr_info[nr].sig = sig;
		ifsr_info[nr].code = code;
		ifsr_info[nr].name = name;
		}

		asmlinkage void __exception
		do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
		{

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