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| 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 13:08:39 -0700 |
| commit | 74c228d20a51ddb1354409fdbed7b72427339d7b (patch) | |
| tree | 524713f7708b7ffd19da588b367a19796503c04f /arch/x86/kernel/process.c | |
| parent | 428e106ae1ad4e45d3fd6978a753db475d0d0ec9 (diff) | |
| download | lwn-74c228d20a51ddb1354409fdbed7b72427339d7b.tar.gz lwn-74c228d20a51ddb1354409fdbed7b72427339d7b.zip | |
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/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index b650cde3f64d..bbc8c4c6e360 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -48,6 +48,7 @@ #include <asm/frame.h> #include <asm/unwind.h> #include <asm/tdx.h> +#include <asm/mmu_context.h> #include "process.h" @@ -368,6 +369,8 @@ void arch_setup_new_exec(void) task_clear_spec_ssb_noexec(current); speculation_ctrl_update(read_thread_flags()); } + + mm_reset_untag_mask(current->mm); } #ifdef CONFIG_X86_IOPL_IOPERM |