From e950631e84e7e38892ffbeee5e1816b270026b0e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 18 Feb 2016 15:50:04 +0000 Subject: [PATCH] arm64: Remove the get_thread_info() function This function was introduced by previous commits implementing UAO. However, it can be replaced with task_thread_info() in uao_thread_switch() or get_fs() in do_page_fault() (the latter being called only on the current context, so no need for using the saved pt_regs). Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/thread_info.h | 6 ------ arch/arm64/kernel/process.c | 15 ++++++--------- arch/arm64/mm/fault.c | 2 +- 3 files changed, 7 insertions(+), 16 deletions(-) diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index eba8db6..abd64bd 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -85,12 +85,6 @@ static inline struct thread_info *current_thread_info(void) return (struct thread_info *)sp_el0; } -/* Access struct thread_info of another thread */ -static inline struct thread_info *get_thread_info(unsigned long thread_stack) -{ - return (struct thread_info *)(thread_stack & ~(THREAD_SIZE - 1)); -} - #define thread_saved_pc(tsk) \ ((unsigned long)(tsk->thread.cpu_context.pc)) #define thread_saved_sp(tsk) \ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index c1ca4ea..8062482 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -315,15 +315,12 @@ static void tls_thread_switch(struct task_struct *next) /* Restore the UAO state depending on next's addr_limit */ static void uao_thread_switch(struct task_struct *next) { - unsigned long next_sp = next->thread.cpu_context.sp; - - if (IS_ENABLED(CONFIG_ARM64_UAO) && - get_thread_info(next_sp)->addr_limit == KERNEL_DS) - asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO, - CONFIG_ARM64_UAO)); - else - asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO, - CONFIG_ARM64_UAO)); + if (IS_ENABLED(CONFIG_ARM64_UAO)) { + if (task_thread_info(next)->addr_limit == KERNEL_DS) + asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO)); + else + asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO)); + } } /* diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index d0762a7..a8eafece 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -234,7 +234,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, } if (permission_fault(esr) && (addr < USER_DS)) { - if (get_thread_info(regs->sp)->addr_limit == KERNEL_DS) + if (get_fs() == KERNEL_DS) panic("Accessing user space memory with fs=KERNEL_DS"); if (!search_exception_tables(regs->pc)) -- 2.7.4