On Tue, 13 Nov 2018 00:08:48 +0300 Alexander Popov <[email protected]> wrote:
> The stackleak_erase() function is called on the trampoline stack at the end > of syscall. This stack is not big enough for ftrace and kprobes operations, > e.g. it can be exhausted if we use kprobe_events for stackleak_erase(). > > So let's disable function tracing and kprobes for stackleak_erase(). > > Reported-by: kernel test robot <[email protected]> > Signed-off-by: Alexander Popov <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]> Thank you! > --- > kernel/stackleak.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/stackleak.c b/kernel/stackleak.c > index e428929..08cb57e 100644 > --- a/kernel/stackleak.c > +++ b/kernel/stackleak.c > @@ -11,6 +11,7 @@ > */ > > #include <linux/stackleak.h> > +#include <linux/kprobes.h> > > #ifdef CONFIG_STACKLEAK_RUNTIME_DISABLE > #include <linux/jump_label.h> > @@ -47,7 +48,7 @@ int stack_erasing_sysctl(struct ctl_table *table, int write, > #define skip_erasing() false > #endif /* CONFIG_STACKLEAK_RUNTIME_DISABLE */ > > -asmlinkage void stackleak_erase(void) > +asmlinkage void notrace stackleak_erase(void) > { > /* It would be nice not to have 'kstack_ptr' and 'boundary' on stack */ > unsigned long kstack_ptr = current->lowest_stack; > @@ -101,6 +102,7 @@ asmlinkage void stackleak_erase(void) > /* Reset the 'lowest_stack' value for the next syscall */ > current->lowest_stack = current_top_of_stack() - THREAD_SIZE/64; > } > +NOKPROBE_SYMBOL(stackleak_erase); > > void __used stackleak_track_stack(void) > { > -- > 2.7.4 > -- Masami Hiramatsu <[email protected]>
