kevin/linux
1
Fork 0
Code

x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking

Browse Source 
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>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20240702132139.3332013-4-yosryahmed%40google.com
This commit is contained in:
Yosry Ahmed 2024-07-02 13:21:39 +00:00 committed by Dave Hansen
parent ec225f8c25
commit b7c35279e0
1 changed files with 4 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/x86/kernel/process_64.c
View File

@ -812,6 +812,9 @@ static void enable_lam_func(void *__mm)
static void mm_enable_lam(struct mm_struct *mm) static void mm_enable_lam(struct mm_struct *mm)
{ {
mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
mm->context.untag_mask = ~GENMASK(62, 57);
/* /*
* Even though the process must still be single-threaded at this * Even though the process must still be single-threaded at this
* point, kernel threads may be using the mm. IPI those kernel * point, kernel threads may be using the mm. IPI those kernel
@ -846,13 +849,7 @@ static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
return -EBUSY; return -EBUSY;
} }
if (!nr_bits) { if (!nr_bits || nr_bits > LAM_U57_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 {
mmap_write_unlock(mm); mmap_write_unlock(mm);
return -EINVAL; return -EINVAL;
} }