x86: shstk: use the new common vm_mmap_shadow_stack() helper

Replace part of the x86 alloc_shstk() content with a call to
vm_mmap_shadow_stack(). There is no functional change.

Link: https://lkml.kernel.org/r/20260225161404.3157851-5-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
index 978232b6d48d76b166cdd4ea96b19ef67fdff4ed..9725e7d89b1efd5b7dbf23159a042c0b1cf5c530 100644 (file)
--- a/arch/x86/kernel/shstk.c
+++ b/arch/x86/kernel/shstk.c
@@ -100,17 +100,9 @@ static int create_rstor_token(unsigned long ssp, unsigned long *token_addr)
 static unsigned long alloc_shstk(unsigned long addr, unsigned long size,
                                 unsigned long token_offset, bool set_res_tok)
 {
-       int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_ABOVE4G;
-       struct mm_struct *mm = current->mm;
-       unsigned long mapped_addr, unused;
+       unsigned long mapped_addr;
 
-       if (addr)
-               flags |= MAP_FIXED_NOREPLACE;
-
-       mmap_write_lock(mm);
-       mapped_addr = do_mmap(NULL, addr, size, PROT_READ, flags,
-                             VM_SHADOW_STACK | VM_WRITE, 0, &unused, NULL);
-       mmap_write_unlock(mm);
+       mapped_addr = vm_mmap_shadow_stack(addr, size, MAP_ABOVE4G);
 
        if (!set_res_tok || IS_ERR_VALUE(mapped_addr))
                goto out;