Andrew Morton suggested using the proper API for reading and writing
kernel areas that might fault.

Signed-off-by: Steven Rostedt
---
arch/x86/kernel/ftrace.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

Index: linux-compile.git/arch/x86/kernel/ftrace.c
================================================== =================
--- linux-compile.git.orig/arch/x86/kernel/ftrace.c 2008-10-22 15:24:15.000000000 -0400
+++ linux-compile.git/arch/x86/kernel/ftrace.c 2008-10-22 15:26:07.000000000 -0400
@@ -74,8 +74,7 @@ ftrace_modify_code(unsigned long ip, uns
*/

/* read the text we want to modify */
- if (__copy_from_user_inatomic(replaced, (char __user *)ip,
- MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
return -EFAULT;

/* Make sure it is what we expect it to be */
@@ -83,8 +82,7 @@ ftrace_modify_code(unsigned long ip, uns
return -EINVAL;

/* replace the text with the new text */
- if (__copy_to_user_inatomic((char __user *)ip, new_code,
- MCOUNT_INSN_SIZE))
+ if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
return -EPERM;

sync_core();

--
--
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