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entry: Drop usage of TIF flags in the generic syscall code 

Now that the flags migration in the common syscall entry code is complete
and the code relies exclusively on thread_info::syscall_work, clean up the
accesses to TI flags in that path.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-10-krisman@collabora.com
This commit is contained in:
Gabriel Krisman Bertazi 2020-11-16 12:42:05 -05:00 committed by Thomas Gleixner
parent 785dc4eb7f
commit 2991552447
2 changed files with 19 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
include/linux/entry-common.h
View File

@ -26,31 +26,29 @@
#endif
/*
* TIF flags handled in syscall_enter_from_user_mode()
* SYSCALL_WORK flags handled in syscall_enter_from_user_mode()
*/
#ifndef ARCH_SYSCALL_ENTER_WORK
# define ARCH_SYSCALL_ENTER_WORK (0)
#ifndef ARCH_SYSCALL_WORK_ENTER
# define ARCH_SYSCALL_WORK_ENTER (0)
#endif
#define SYSCALL_ENTER_WORK ARCH_SYSCALL_ENTER_WORK
/*
* TIF flags handled in syscall_exit_to_user_mode()
* SYSCALL_WORK flags handled in syscall_exit_to_user_mode()
*/
#ifndef ARCH_SYSCALL_EXIT_WORK
# define ARCH_SYSCALL_EXIT_WORK (0)
#ifndef ARCH_SYSCALL_WORK_EXIT
# define ARCH_SYSCALL_WORK_EXIT (0)
#endif
#define SYSCALL_EXIT_WORK ARCH_SYSCALL_EXIT_WORK
#define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \
SYSCALL_WORK_SYSCALL_TRACEPOINT | \
SYSCALL_WORK_SYSCALL_TRACE | \
SYSCALL_WORK_SYSCALL_EMU | \
SYSCALL_WORK_SYSCALL_AUDIT)
SYSCALL_WORK_SYSCALL_AUDIT | \
ARCH_SYSCALL_WORK_ENTER)
#define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT | \
SYSCALL_WORK_SYSCALL_TRACE | \
SYSCALL_WORK_SYSCALL_AUDIT)
SYSCALL_WORK_SYSCALL_AUDIT | \
ARCH_SYSCALL_WORK_EXIT)
/*
* TIF flags handled in exit_to_user_mode_loop()
@ -136,8 +134,8 @@ void syscall_enter_from_user_mode_prepare(struct pt_regs *regs);
*
* It handles the following work items:
*
* 1) TIF flag dependent invocations of arch_syscall_enter_tracehook(),
* __secure_computing(), trace_sys_enter()
* 1) syscall_work flag dependent invocations of
* arch_syscall_enter_tracehook(), __secure_computing(), trace_sys_enter()
* 2) Invocation of audit_syscall_entry()
*/
long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall);

17
kernel/entry/common.c
View File

@ -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 work)
unsigned long work)
{
long ret = 0;
@ -75,11 +75,9 @@ 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 (work & SYSCALL_WORK_ENTER || ti_work & SYSCALL_ENTER_WORK)
syscall = syscall_trace_enter(regs, syscall, ti_work, work);
if (work & SYSCALL_WORK_ENTER)
syscall = syscall_trace_enter(regs, syscall, work);
return syscall;
}
@ -227,8 +225,8 @@ static inline bool report_single_step(unsigned long work)
}
#endif
static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work,
unsigned long work)
static void syscall_exit_work(struct pt_regs *regs, unsigned long work)
{
bool step;
@ -249,7 +247,6 @@ 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);
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
@ -266,8 +263,8 @@ 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(work & SYSCALL_WORK_EXIT || cached_flags & SYSCALL_EXIT_WORK))
syscall_exit_work(regs, cached_flags, work);
if (unlikely(work & SYSCALL_WORK_EXIT))
syscall_exit_work(regs, work);
}
__visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)