[PATCH v2 4/5] x86: shstk: Use the new common vm_mmap_shadow_stack() helper
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2026-02-25 16:14:25
Also in:
linux-mm, linux-riscv, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Replace part of the x86 alloc_shstk() content with a call to vm_mmap_shadow_stack(). There is no functional change. 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> --- arch/x86/kernel/shstk.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
index 978232b6d48d..9725e7d89b1e 100644
--- 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;