| Message ID | 20181128081239.18317-1-anders.roxell@linaro.org |
|---|---|
| State | Accepted |
| Commit | 903e8ff86753e6f327bb92166a0665e4ecb8e2e7 |
| Headers | show |
| Series | [1/2] kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc as notrace | expand |
On Wed, 28 Nov 2018 09:12:39 +0100 Anders Roxell <anders.roxell@linaro.org> wrote: > Since __sanitizer_cov_trace_pc is marked as notrace, function calls in > __sanitizer_cov_trace_pc shouldn't be traced either. The function > ftrace_graph_caller() gets called for each function that isn't marked > 'notrace', like canonicalize_ip(). This is the call trace from a run: > > [ 139.644550] ftrace_graph_caller+0x1c/0x24 > [ 139.648352] canonicalize_ip+0x18/0x28 > [ 139.652313] __sanitizer_cov_trace_pc+0x14/0x58 > [ 139.656184] sched_clock+0x34/0x1e8 > [ 139.659759] trace_clock_local+0x40/0x88 > [ 139.663722] ftrace_push_return_trace+0x8c/0x1f0 > [ 139.667767] prepare_ftrace_return+0xa8/0x100 > [ 139.671709] ftrace_graph_caller+0x1c/0x24 > > Rework so that the functions check_kcov_mode and canonicalize_ip that is > callef from __sanitizer_cov_trace_pc also is marked as notrace. > > Co-developed-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Signen-off-by: Anders Roxell <anders.roxell@linaro.org> > --- Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> -- Steve
diff --git a/kernel/kcov.c b/kernel/kcov.c index 3ebd09efe72a..97959d7b77e2 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -56,7 +56,7 @@ struct kcov { struct task_struct *t; }; -static bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t) +static notrace bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t) { unsigned int mode; @@ -78,7 +78,7 @@ static bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t) return mode == needed_mode; } -static unsigned long canonicalize_ip(unsigned long ip) +static notrace unsigned long canonicalize_ip(unsigned long ip) { #ifdef CONFIG_RANDOMIZE_BASE ip -= kaslr_offset();
Since __sanitizer_cov_trace_pc is marked as notrace, function calls in __sanitizer_cov_trace_pc shouldn't be traced either. The function ftrace_graph_caller() gets called for each function that isn't marked 'notrace', like canonicalize_ip(). This is the call trace from a run: [ 139.644550] ftrace_graph_caller+0x1c/0x24 [ 139.648352] canonicalize_ip+0x18/0x28 [ 139.652313] __sanitizer_cov_trace_pc+0x14/0x58 [ 139.656184] sched_clock+0x34/0x1e8 [ 139.659759] trace_clock_local+0x40/0x88 [ 139.663722] ftrace_push_return_trace+0x8c/0x1f0 [ 139.667767] prepare_ftrace_return+0xa8/0x100 [ 139.671709] ftrace_graph_caller+0x1c/0x24 Rework so that the functions check_kcov_mode and canonicalize_ip that is callef from __sanitizer_cov_trace_pc also is marked as notrace. Co-developed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signen-off-by: Anders Roxell <anders.roxell@linaro.org> --- kernel/kcov.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.19.2