Commit 903e8ff8 authored by Anders Roxell's avatar Anders Roxell Committed by Linus Torvalds

kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace

Since __sanitizer_cov_trace_pc() is marked as notrace, function calls in
__sanitizer_cov_trace_pc() shouldn't be traced either.
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 check_kcov_mode() and canonicalize_ip() that are called
from __sanitizer_cov_trace_pc() are also marked as notrace.

Link: http://lkml.kernel.org/r/20181128081239.18317-1-anders.roxell@linaro.orgSigned-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signen-off-by: default avatarAnders Roxell <anders.roxell@linaro.org>
Co-developed-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e0c27447
......@@ -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();
......
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