mseal sysmap: enable arm64

Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on arm64, covering the
vdso, vvar, and compat-mode vectors and sigpage mappings.

Production release testing passes on Android and Chrome OS.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Cc: Adhemerval Zanella <[email protected]>
Cc: Alexander Mikhalitsyn <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Anna-Maria Behnsen <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Benjamin Berg <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Elliot Hughes <[email protected]>
Cc: Florian Faineli <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Linus Waleij <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Matthew Wilcow (Oracle) <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: peaktocreek

arch/arm64/Kconfig

@@ -38,6 +38,7 @@ config ARM64
 	select ARCH_HAS_KEEPINITRD
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEM_ENCRYPT
+	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT

arch/arm64/kernel/vdso.c

@@ -130,7 +130,8 @@ static int __setup_additional_pages(enum vdso_abi abi,
 	mm->context.vdso = (void *)vdso_base;
 	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
 				       VM_READ|VM_EXEC|gp_flags|
-				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+				       VM_SEALED_SYSMAP,
 				       vdso_info[abi].cm);
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -256,7 +257,8 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
 	 */
 	ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE,
 				       VM_READ | VM_EXEC |
-				       VM_MAYREAD | VM_MAYEXEC,
+				       VM_MAYREAD | VM_MAYEXEC |
+				       VM_SEALED_SYSMAP,
 				       &aarch32_vdso_maps[AA32_MAP_VECTORS]);
 
 	return PTR_ERR_OR_ZERO(ret);
@@ -279,7 +281,8 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
 	 */
 	ret = _install_special_mapping(mm, addr, PAGE_SIZE,
 				       VM_READ | VM_EXEC | VM_MAYREAD |
-				       VM_MAYWRITE | VM_MAYEXEC,
+				       VM_MAYWRITE | VM_MAYEXEC |
+				       VM_SEALED_SYSMAP,
 				       &aarch32_vdso_maps[AA32_MAP_SIGPAGE]);
 	if (IS_ERR(ret))
 		goto out;