From b5a5a01d8e9a44ecb18dc31d471233cad2f88291 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 2 Dec 2020 13:15:56 +0000 Subject: [PATCH] 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: Mark Rutland Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-11-mark.rutland@arm.com Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/thread_info.h | 6 ++---- arch/arm64/kernel/signal.c | 3 --- 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 3a88a55de568..015beafe58f5 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -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 | \ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index a8184cad8890..af5c6c6638f7 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -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); -- 2.39.2