Commit 5a735583 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

arm/ftrace: Use __patch_text() 



Instead of flipping text protection, use the patch_text infrastructure
that uses a fixmap alias where required.

This removes the last user of set_all_modules_text_*().

Tested-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ard.biesheuvel@linaro.org
Cc: james.morse@arm.com
Cc: rabin@rab.in
Link: https://lkml.kernel.org/r/20191113092636.GG4131@hirez.programming.kicks-ass.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5c02ece8

arch/arm/kernel/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -49,8 +49,8 @@ obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o 
obj-$(CONFIG_HAVE_ARM_TWD)	+= smp_twd.o

obj-$(CONFIG_ARM_ARCH_TIMER)	+= arch_timer.o

obj-$(CONFIG_FUNCTION_TRACER)	+= entry-ftrace.o

obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o insn.o

obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o insn.o

obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o insn.o patch.o

obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o insn.o patch.o

obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o insn.o patch.o

obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o

# Main staffs in KPROBES are in arch/arm/probes/ .

arch/arm/kernel/ftrace.c

+2 −8
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <asm/ftrace.h>

#include <asm/insn.h>

#include <asm/set_memory.h>

#include <asm/patch.h>



#ifdef CONFIG_THUMB2_KERNEL

#define	NOP		0xf85deb04	/* pop.w {lr} */
@@ -35,9 +36,7 @@ static int __ftrace_modify_code(void *data) 
{

	int *command = data;



	set_kernel_text_rw();

	ftrace_modify_all_code(*command);

	set_kernel_text_ro();



	return 0;

}
@@ -59,13 +58,11 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr) 


int ftrace_arch_code_modify_prepare(void)

{

	set_all_modules_text_rw();

	return 0;

}



int ftrace_arch_code_modify_post_process(void)

{

	set_all_modules_text_ro();

	/* Make sure any TLB misses during machine stop are cleared. */

	flush_tlb_all();

	return 0;
@@ -97,10 +94,7 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old, 
			return -EINVAL;

	}



	if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE))

		return -EPERM;



	flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);

	__patch_text((void *)pc, new);



	return 0;

}

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