diff options
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index c0062ad1e847..6fd7c4a1e532 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -121,15 +121,17 @@ static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr) } static int ftrace_modify_code(unsigned long pc, unsigned long old, - unsigned long new) + unsigned long new, bool validate) { unsigned long replaced; - if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE)) - return -EFAULT; + if (validate) { + if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE)) + return -EFAULT; - if (replaced != old) - return -EINVAL; + if (replaced != old) + return -EINVAL; + } if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE)) return -EPERM; @@ -141,23 +143,21 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old, int ftrace_update_ftrace_func(ftrace_func_t func) { - unsigned long pc, old; + unsigned long pc; unsigned long new; int ret; pc = (unsigned long)&ftrace_call; - memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(pc, (unsigned long)func); - ret = ftrace_modify_code(pc, old, new); + ret = ftrace_modify_code(pc, 0, new, false); #ifdef CONFIG_OLD_MCOUNT if (!ret) { pc = (unsigned long)&ftrace_call_old; - memcpy(&old, &ftrace_call_old, MCOUNT_INSN_SIZE); new = ftrace_call_replace(pc, (unsigned long)func); - ret = ftrace_modify_code(pc, old, new); + ret = ftrace_modify_code(pc, 0, new, false); } #endif @@ -172,7 +172,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) old = ftrace_nop_replace(rec); new = ftrace_call_replace(ip, adjust_address(rec, addr)); - return ftrace_modify_code(rec->ip, old, new); + return ftrace_modify_code(rec->ip, old, new, true); } int ftrace_make_nop(struct module *mod, @@ -185,7 +185,7 @@ int ftrace_make_nop(struct module *mod, old = ftrace_call_replace(ip, adjust_address(rec, addr)); new = ftrace_nop_replace(rec); - ret = ftrace_modify_code(ip, old, new); + ret = ftrace_modify_code(ip, old, new, true); #ifdef CONFIG_OLD_MCOUNT if (ret == -EINVAL && addr == MCOUNT_ADDR) { @@ -193,7 +193,7 @@ int ftrace_make_nop(struct module *mod, old = ftrace_call_replace(ip, adjust_address(rec, addr)); new = ftrace_nop_replace(rec); - ret = ftrace_modify_code(ip, old, new); + ret = ftrace_modify_code(ip, old, new, true); } #endif @@ -254,7 +254,7 @@ static int __ftrace_modify_caller(unsigned long *callsite, unsigned long old = enable ? nop : branch; unsigned long new = enable ? branch : nop; - return ftrace_modify_code(pc, old, new); + return ftrace_modify_code(pc, old, new, true); } static int ftrace_modify_graph_caller(bool enable) |