Commit b5a5a01d authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
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arm64: uaccess: remove addr_limit_user_check() 



Now that set_fs() is gone, addr_limit_user_check() is redundant. Remove
the checks and associated thread flag.

To ensure that _TIF_WORK_MASK can be used as an immediate value in an
AND instruction (as it is in `ret_to_user`), TIF_MTE_ASYNC_FAULT is
renumbered to keep the constituent bits of _TIF_WORK_MASK contiguous.

There should be no functional change as a result of this patch.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201202131558.39270-11-mark.rutland@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 3d2403fd

arch/arm64/include/asm/thread_info.h

+2 −4
Original line number Diff line number Diff line
@@ -63,8 +63,7 @@ void arch_release_task_struct(struct task_struct *tsk); 
#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_FOREIGN_FPSTATE	3	/* CPU's FP state is not current's */

#define TIF_UPROBE		4	/* uprobe breakpoint or singlestep */

#define TIF_FSCHECK		5	/* Check FS is USER_DS on return */

#define TIF_MTE_ASYNC_FAULT	6	/* MTE Asynchronous Tag Check Fault */

#define TIF_MTE_ASYNC_FAULT	5	/* MTE Asynchronous Tag Check Fault */

#define TIF_SYSCALL_TRACE	8	/* syscall trace active */

#define TIF_SYSCALL_AUDIT	9	/* syscall auditing */

#define TIF_SYSCALL_TRACEPOINT	10	/* syscall tracepoint for ftrace */
@@ -90,7 +89,6 @@ void arch_release_task_struct(struct task_struct *tsk); 
#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)

#define _TIF_UPROBE		(1 << TIF_UPROBE)

#define _TIF_FSCHECK		(1 << TIF_FSCHECK)

#define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)

#define _TIF_32BIT		(1 << TIF_32BIT)

#define _TIF_SVE		(1 << TIF_SVE)
@@ -98,7 +96,7 @@ void arch_release_task_struct(struct task_struct *tsk); 


#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \

				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \

				 _TIF_UPROBE | _TIF_FSCHECK | _TIF_MTE_ASYNC_FAULT)

				 _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT)



#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \

arch/arm64/kernel/signal.c

+0 −3
Original line number Diff line number Diff line
@@ -922,9 +922,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, 
	trace_hardirqs_off();



	do {

		/* Check valid user FS if needed */

		addr_limit_user_check();



		if (thread_flags & _TIF_NEED_RESCHED) {

			/* Unmask Debug and SError for the next task */

			local_daif_restore(DAIF_PROCCTX_NOIRQ);