riscv: remove address space overrides using set_fs()

Stop providing the possibility to override the address space using
set_fs() now that there is no need for that any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 1046ee7..12642ba 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -87,7 +87,6 @@ config RISCV
        select SPARSE_IRQ
        select SYSCTL_EXCEPTION_TRACE
        select THREAD_INFO_IN_TASK
-       select SET_FS
        select UACCESS_MEMCPY if !MMU
 
 config ARCH_MMAP_RND_BITS_MIN

diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 464a2bb..a390711 100644 (file)
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -24,10 +24,6 @@
 #include <asm/processor.h>
 #include <asm/csr.h>
 
-typedef struct {
-       unsigned long seg;
-} mm_segment_t;
-
 /*
  * low level task data that entry.S needs immediate access to
  * - this struct should fit entirely inside of one cache line
@@ -39,7 +35,6 @@ typedef struct {
 struct thread_info {
        unsigned long           flags;          /* low level flags */
        int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
-       mm_segment_t            addr_limit;
        /*
         * These stack pointers are overwritten on every system call or
         * exception.  SP is also saved to the stack it can be recovered when
@@ -59,7 +54,6 @@ struct thread_info {
 {                                              \
        .flags          = 0,                    \
        .preempt_count  = INIT_PREEMPT_COUNT,   \
-       .addr_limit     = KERNEL_DS,            \
 }
 
 #endif /* !__ASSEMBLY__ */

diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index 264e52f..c47e6b3 100644 (file)
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -26,29 +26,6 @@
 #define __disable_user_access()                                                        \
        __asm__ __volatile__ ("csrc sstatus, %0" : : "r" (SR_SUM) : "memory")
 
-/*
- * The fs value determines whether argument validity checking should be
- * performed or not.  If get_fs() == USER_DS, checking is performed, with
- * get_fs() == KERNEL_DS, checking is bypassed.
- *
- * For historical reasons, these macros are grossly misnamed.
- */
-
-#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-
-#define KERNEL_DS      MAKE_MM_SEG(~0UL)
-#define USER_DS                MAKE_MM_SEG(TASK_SIZE)
-
-#define get_fs()       (current_thread_info()->addr_limit)
-
-static inline void set_fs(mm_segment_t fs)
-{
-       current_thread_info()->addr_limit = fs;
-}
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-#define user_addr_max()        (get_fs().seg)
-
 /**
  * access_ok: - Checks if a user space pointer is valid
  * @addr: User space pointer to start of block to check
@@ -76,9 +53,7 @@ static inline void set_fs(mm_segment_t fs)
  */
 static inline int __access_ok(unsigned long addr, unsigned long size)
 {
-       const mm_segment_t fs = get_fs();
-
-       return size <= fs.seg && addr <= fs.seg - size;
+       return size <= TASK_SIZE && addr <= TASK_SIZE - size;
 }
 
 /*

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 2b97c49..19225ec 100644 (file)
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -84,7 +84,6 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
        }
        regs->epc = pc;
        regs->sp = sp;
-       set_fs(USER_DS);
 }
 
 void flush_thread(void)