From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kcov: move t->kcov assignments into kcov_start/stop Every time kcov_start/stop() is called, t->kcov is also assigned, so move the assignment into the functions. Link: http://lkml.kernel.org/r/6644839d3567df61ade3c4b246a46cacbe4f9e11.1585233617.git.andreyknvl@xxxxxxxxxx Link: http://lkml.kernel.org/r/82625ef3ff878f0b585763cc31d09d9b08ca37d6.1584655448.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/kcov.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) --- a/kernel/kcov.c~kcov-move-t-kcov-assignments-into-kcov_start-stop +++ a/kernel/kcov.c @@ -309,10 +309,12 @@ void notrace __sanitizer_cov_trace_switc EXPORT_SYMBOL(__sanitizer_cov_trace_switch); #endif /* ifdef CONFIG_KCOV_ENABLE_COMPARISONS */ -static void kcov_start(struct task_struct *t, unsigned int size, - void *area, enum kcov_mode mode, int sequence) +static void kcov_start(struct task_struct *t, struct kcov *kcov, + unsigned int size, void *area, enum kcov_mode mode, + int sequence) { kcov_debug("t = %px, size = %u, area = %px\n", t, size, area); + t->kcov = kcov; /* Cache in task struct for performance. */ t->kcov_size = size; t->kcov_area = area; @@ -326,6 +328,7 @@ static void kcov_stop(struct task_struct { WRITE_ONCE(t->kcov_mode, KCOV_MODE_DISABLED); barrier(); + t->kcov = NULL; t->kcov_size = 0; t->kcov_area = NULL; } @@ -333,7 +336,6 @@ static void kcov_stop(struct task_struct static void kcov_task_reset(struct task_struct *t) { kcov_stop(t); - t->kcov = NULL; t->kcov_sequence = 0; t->kcov_handle = 0; } @@ -584,9 +586,8 @@ static int kcov_ioctl_locked(struct kcov return mode; kcov_fault_in_area(kcov); kcov->mode = mode; - kcov_start(t, kcov->size, kcov->area, kcov->mode, + kcov_start(t, kcov, kcov->size, kcov->area, kcov->mode, kcov->sequence); - t->kcov = kcov; kcov->t = t; /* Put either in kcov_task_exit() or in KCOV_DISABLE. */ kcov_get(kcov); @@ -778,7 +779,6 @@ void kcov_remote_start(u64 handle) kcov = remote->kcov; /* Put in kcov_remote_stop(). */ kcov_get(kcov); - t->kcov = kcov; /* * Read kcov fields before unlock to prevent races with * KCOV_DISABLE / kcov_remote_reset(). @@ -792,7 +792,6 @@ void kcov_remote_start(u64 handle) if (!area) { area = vmalloc(size * sizeof(unsigned long)); if (!area) { - t->kcov = NULL; kcov_put(kcov); return; } @@ -800,7 +799,7 @@ void kcov_remote_start(u64 handle) /* Reset coverage size. */ *(u64 *)area = 0; - kcov_start(t, size, area, mode, sequence); + kcov_start(t, kcov, size, area, mode, sequence); } EXPORT_SYMBOL(kcov_remote_start); @@ -873,7 +872,6 @@ void kcov_remote_stop(void) return; kcov_stop(t); - t->kcov = NULL; spin_lock(&kcov->lock); /* _
