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Subject[PATCH 8/8] riscv: remove address space overrides using set_fs()
Date
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>
---
arch/riscv/Kconfig | 1 -
arch/riscv/include/asm/thread_info.h | 6 ------
arch/riscv/include/asm/uaccess.h | 27 +--------------------------
arch/riscv/kernel/process.c | 1 -
4 files changed, 1 insertion(+), 34 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 460e3971a80fde..33dde87218ddab 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -86,7 +86,6 @@ 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 464a2bbc97ea33..a390711129de64 100644
--- 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 264e52fb62b143..c47e6b35c551f4 100644
--- 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 2b97c493427c9e..19225ec65db62f 100644
--- 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)
--
2.28.0
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