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 <catalin.marinas@arm.com>
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 @@
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 @@
/* 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 @@
}
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))