Messages in this thread Patch in this message | | | Date | Thu, 26 Apr 2012 14:31:19 -0400 | From | Steven Rostedt <> | Subject | [PATCH 3/3][RFC] ftrace/ppc: Use patch_instruction instead of probe_kernel_write() |
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From: Steven Rostedt <srostedt@redhat.com>
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: Steven Rostedt <rostedt@goodmis.org> --- arch/powerpc/kernel/ftrace.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 84a5ddd..4e376bc 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -63,11 +63,9 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) return -EINVAL; /* 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; - flush_icache_range(ip, ip + 8); - return 0; } @@ -212,12 +210,9 @@ __ftrace_make_nop(struct module *mod, */ op = 0x48000008; /* b +8 */ - if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE)) + if (patch_instruction((unsigned int *)ip, op)) return -EPERM; - - flush_icache_range(ip, ip + 8); - return 0; } @@ -286,11 +281,9 @@ __ftrace_make_nop(struct module *mod, op = PPC_INST_NOP; - if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE)) + if (patch_instruction((unsigned int *)ip, op)) return -EPERM; - flush_icache_range(ip, ip + 8); - return 0; } #endif /* PPC64 */ @@ -426,11 +419,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 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; - flush_icache_range(ip, ip + 8); - return 0; } #endif /* CONFIG_PPC64 */ -- 1.7.9.5
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