diff options
author | Christoph Hellwig <hch@lst.de> | 2020-09-03 17:22:40 +0300 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-09-09 05:21:36 +0300 |
commit | 47058bb54b57962b3958a936ddbc59355e4c5504 (patch) | |
tree | b1399d96916177ef63b8a86bf30daceb35508959 /arch/x86/include/asm/uaccess.h | |
parent | a1d826d475aafe63775b910e86ccd1bcf1e5a6e1 (diff) | |
download | linux-47058bb54b57962b3958a936ddbc59355e4c5504.tar.xz |
x86: 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. To properly
handle the TASK_SIZE_MAX checking for 4 vs 5-level page tables on
x86 a new alternative is introduced, which just like the one in
entry_64.S has to use the hardcoded virtual address bits to escape
the fact that TASK_SIZE_MAX isn't actually a constant when 5-level
page tables are enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
-rw-r--r-- | arch/x86/include/asm/uaccess.h | 26 |
1 files changed, 1 insertions, 25 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index ecefaffd15d4..a4ceda0510ea 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -13,30 +13,6 @@ #include <asm/extable.h> /* - * 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(-1UL) -#define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) - -#define get_fs() (current->thread.addr_limit) -static inline void set_fs(mm_segment_t fs) -{ - current->thread.addr_limit = fs; - /* On user-mode return, check fs is correct */ - set_thread_flag(TIF_FSCHECK); -} - -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -#define user_addr_max() (current->thread.addr_limit.seg) - -/* * Test whether a block of memory is a valid user space address. * Returns 0 if the range is valid, nonzero otherwise. */ @@ -93,7 +69,7 @@ static inline bool pagefault_disabled(void); #define access_ok(addr, size) \ ({ \ WARN_ON_IN_IRQ(); \ - likely(!__range_not_ok(addr, size, user_addr_max())); \ + likely(!__range_not_ok(addr, size, TASK_SIZE_MAX)); \ }) /* |