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Commit 65b8c722 authored by Steven Rostedt's avatar Steven Rostedt Committed by Benjamin Herrenschmidt
Browse files

powerpc/ftrace: Use patch_instruction instead of probe_kernel_write() 



The patch_instruction() interface is made to modify kernel text. It is
safer to use that then the probe_kernel_write() when modifying kernel
code.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent b6e37968

arch/powerpc/kernel/ftrace.c

+4 −13
Original line number Original line Diff line number Diff line
@@ -63,11 +63,9 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) 
		return -EINVAL;

		return -EINVAL;





	/* replace the text with the new text */

	/* replace the text with the new text */

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

	if (patch_instruction((unsigned int *)ip, new))

		return -EPERM;

		return -EPERM;





	flush_icache_range(ip, ip + 8);



	return 0;

	return 0;

}

}
@@ -212,12 +210,9 @@ __ftrace_make_nop(struct module *mod, 
	 */

	 */

	op = 0x48000008;	/* b +8 */

	op = 0x48000008;	/* b +8 */





	if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))

	if (patch_instruction((unsigned int *)ip, op))

		return -EPERM;

		return -EPERM;







	flush_icache_range(ip, ip + 8);



	return 0;

	return 0;

}

}
@@ -286,11 +281,9 @@ __ftrace_make_nop(struct module *mod, 




	op = PPC_INST_NOP;

	op = PPC_INST_NOP;





	if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))

	if (patch_instruction((unsigned int *)ip, op))

		return -EPERM;

		return -EPERM;





	flush_icache_range(ip, ip + 8);



	return 0;

	return 0;

}

}

#endif /* PPC64 */

#endif /* PPC64 */
@@ -426,11 +419,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 




	pr_devel("write to %lx\n", rec->ip);

	pr_devel("write to %lx\n", rec->ip);





	if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))

	if (patch_instruction((unsigned int *)ip, op))

		return -EPERM;

		return -EPERM;





	flush_icache_range(ip, ip + 8);



	return 0;

	return 0;

}

}

#endif /* CONFIG_PPC64 */

#endif /* CONFIG_PPC64 */