diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-12 14:26:01 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-03-16 23:08:39 +0300 |
| commit | 74c228d20a51ddb1354409fdbed7b72427339d7b (patch) | |
| tree | 524713f7708b7ffd19da588b367a19796503c04f /arch/x86/include/asm/mmu.h | |
| parent | 428e106ae1ad4e45d3fd6978a753db475d0d0ec9 (diff) | |
| download | linux-74c228d20a51ddb1354409fdbed7b72427339d7b.tar.xz | |
x86/uaccess: Provide untagged_addr() and remove tags before address check
untagged_addr() is a helper used by the core-mm to strip tag bits and
get the address to the canonical shape based on rules of the current
thread. It only handles userspace addresses.
The untagging mask is stored in per-CPU variable and set on context
switching to the task.
The tags must not be included into check whether it's okay to access the
userspace address. Strip tags in access_ok().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-7-kirill.shutemov%40linux.intel.com
Diffstat (limited to 'arch/x86/include/asm/mmu.h')
| -rw-r--r-- | arch/x86/include/asm/mmu.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index 22fc9fbf1d0a..9cac8c45a647 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -45,6 +45,9 @@ typedef struct { #ifdef CONFIG_ADDRESS_MASKING /* Active LAM mode: X86_CR3_LAM_U48 or X86_CR3_LAM_U57 or 0 (disabled) */ unsigned long lam_cr3_mask; + + /* Significant bits of the virtual address. Excludes tag bits. */ + u64 untag_mask; #endif struct mutex lock; |