Ftrace modifies function calls using Int3 breakpoints on x86. It patches all functions in parallel to reduce the number of sync() calls. If some function cannot be modified, it tries to recover and remove the other pending breakpoints.
The recovery currently does not work on x86_64 because the address is read-only. We need to use ftrace_write() that gets write access via the kernel identity mapping. It is used everywhere else in the code. Signed-off-by: Petr Mladek <pmla...@suse.cz> --- arch/x86/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index e7f3f3f565de..30d63c4a4195 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -449,7 +449,7 @@ static int remove_breakpoint(struct dyn_ftrace *rec) update: /* Put back the first byte */ - return probe_kernel_write((void *)ip, valid_ins, 1); + return ftrace_write(ip, valid_ins, 1); } static int add_update_code(unsigned long ip, unsigned const char *new) -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/