diff mbox series

[3/3] x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking

Message ID 20240312035951.3535980-3-yosryahmed@google.com (mailing list archive)
State New
Headers show
Series [1/3] x86/mm: Use IPIs to synchronize LAM enablement | expand

Commit Message

Yosry Ahmed March 12, 2024, 3:59 a.m. UTC
There are two separate checks in prctl_enable_tagged_addr() that nr_bits
is in the correct range. The checks are arranged such the correct case
is sandwiched between both error cases, which do exactly the same thing.

Simplify the if condition and pull the correct case outside with the
rest of the success code path.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
 arch/x86/kernel/process_64.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

Comments

Kirill A. Shutemov March 12, 2024, 12:36 p.m. UTC | #1
On Tue, Mar 12, 2024 at 03:59:51AM +0000, Yosry Ahmed wrote:
> There are two separate checks in prctl_enable_tagged_addr() that nr_bits
> is in the correct range. The checks are arranged such the correct case
> is sandwiched between both error cases, which do exactly the same thing.
> 
> Simplify the if condition and pull the correct case outside with the
> rest of the success code path.
> 
> Signed-off-by: Yosry Ahmed <yosryahmed@google.com>

Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
diff mbox series

Patch

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 748d2b3bdb985..0608c4df4e95d 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -783,17 +783,13 @@  static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
 		return -EBUSY;
 	}
 
-	if (!nr_bits) {
-		mmap_write_unlock(mm);
-		return -EINVAL;
-	} else if (nr_bits <= LAM_U57_BITS) {
-		mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
-		mm->context.untag_mask =  ~GENMASK(62, 57);
-	} else {
+	if (!nr_bits || nr_bits > LAM_U57_BITS) {
 		mmap_write_unlock(mm);
 		return -EINVAL;
 	}
 
+	mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
+	mm->context.untag_mask =  ~GENMASK(62, 57);
 	on_each_cpu_mask(mm_cpumask(mm), enable_lam_func, mm, true);
 	set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags);