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arm/ftrace: Use __patch_text()

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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: Will Deacon <will@kernel.org>
Signed-off-by: Peter 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: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2019-10-15 21:07:35 +02:00 committed by Ingo Molnar
parent 5c02ece818
commit 5a735583b7
2 changed files with 4 additions and 10 deletions
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4
arch/arm/kernel/Makefile
View file

@ -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/ .

10
arch/arm/kernel/ftrace.c
View file

@ -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;
}