Commit b86678cf authored by Gabriel Krisman Bertazi's avatar Gabriel Krisman Bertazi Committed by Thomas Gleixner
Browse files

entry: Wire up syscall_work in common entry code 



Prepare the common entry code to use the SYSCALL_WORK flags. They will
be defined in subsequent patches for each type of syscall
work. SYSCALL_WORK_ENTRY/EXIT are defined for the transition, as they
will replace the TIF_ equivalent defines.

Signed-off-by: default avatarGabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-4-krisman@collabora.com
parent 3136b93c

include/linux/entry-common.h

+3 −0
Original line number Diff line number Diff line
@@ -64,6 +64,9 @@ 
	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT |			\

	 _TIF_SYSCALL_TRACEPOINT | ARCH_SYSCALL_EXIT_WORK)



#define SYSCALL_WORK_ENTER	(0)

#define SYSCALL_WORK_EXIT	(0)



/*

 * TIF flags handled in exit_to_user_mode_loop()

 */

kernel/entry/common.c

+9 −6
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static inline void syscall_enter_audit(struct pt_regs *regs, long syscall) 
}



static long syscall_trace_enter(struct pt_regs *regs, long syscall,

				unsigned long ti_work)

				unsigned long ti_work, unsigned long work)

{

	long ret = 0;
@@ -74,11 +74,12 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall, 
static __always_inline long

__syscall_enter_from_user_work(struct pt_regs *regs, long syscall)

{

	unsigned long work = READ_ONCE(current_thread_info()->syscall_work);

	unsigned long ti_work;



	ti_work = READ_ONCE(current_thread_info()->flags);

	if (ti_work & SYSCALL_ENTER_WORK)

		syscall = syscall_trace_enter(regs, syscall, ti_work);

	if (work & SYSCALL_WORK_ENTER || ti_work & SYSCALL_ENTER_WORK)

		syscall = syscall_trace_enter(regs, syscall, ti_work, work);



	return syscall;

}
@@ -225,7 +226,8 @@ static inline bool report_single_step(unsigned long ti_work) 
}

#endif



static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work)

static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work,

			      unsigned long work)

{

	bool step;
@@ -245,6 +247,7 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work) 
 */

static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs)

{

	unsigned long work = READ_ONCE(current_thread_info()->syscall_work);

	u32 cached_flags = READ_ONCE(current_thread_info()->flags);

	unsigned long nr = syscall_get_nr(current, regs);
@@ -262,8 +265,8 @@ static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs) 
	 * enabled, we want to run them exactly once per syscall exit with

	 * interrupts enabled.

	 */

	if (unlikely(cached_flags & SYSCALL_EXIT_WORK))

		syscall_exit_work(regs, cached_flags);

	if (unlikely(work & SYSCALL_WORK_EXIT || cached_flags & SYSCALL_EXIT_WORK))

		syscall_exit_work(regs, cached_flags, work);

}



__visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)