[PATCH 2/4] arm64: mm: Provide prot param in trans_pgd_idmap_page()'s prototype

From: Pingfan Liu <piliu@redhat.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Pingfan Liu <piliu@redhat.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Pasha Tatashin <pasha.tatashin@soleen.com>
Subject: [PATCH 2/4] arm64: mm: Provide prot param in trans_pgd_idmap_page()'s prototype
Date: Thu, 28 Mar 2024 19:56:52 +0800	[thread overview]
Message-ID: <20240328115656.24090-3-piliu@redhat.com> (raw)
In-Reply-To: <20240328115656.24090-1-piliu@redhat.com>

Since relocate_kernel code will build stack at the rear of the page,
it requires 'wx' on the page. Adapting the prototype of
trans_pgd_idmap_page() to make it doable.

The trans_pgd_idmap_page() can be enhanced further to support multiple
pages. But since the change has met the requirement, it is not
necessary to enhance for the time being.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
To: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/include/asm/trans_pgd.h | 2 +-
 arch/arm64/kernel/hibernate.c      | 3 ++-
 arch/arm64/kernel/machine_kexec.c  | 4 ++--
 arch/arm64/mm/trans_pgd.c          | 4 ++--
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/trans_pgd.h b/arch/arm64/include/asm/trans_pgd.h
index 033d400a4ea4..c55a8a5670a8 100644
--- a/arch/arm64/include/asm/trans_pgd.h
+++ b/arch/arm64/include/asm/trans_pgd.h
@@ -31,7 +31,7 @@ int trans_pgd_create_copy(struct trans_pgd_info *info, pgd_t **trans_pgd,
 			  unsigned long start, unsigned long end);
 
 int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
-			 unsigned long *t0sz, void *page);
+			 unsigned long *t0sz, void *page, pgprot_t prot);
 
 int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
 			       phys_addr_t *el2_vectors);
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 02870beb271e..0c5ce99b7acf 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -203,7 +203,8 @@ static int create_safe_exec_page(void *src_start, size_t length,
 
 	memcpy(page, src_start, length);
 	caches_clean_inval_pou((unsigned long)page, (unsigned long)page + length);
-	rc = trans_pgd_idmap_page(&trans_info, &trans_ttbr0, &t0sz, page);
+	rc = trans_pgd_idmap_page(&trans_info, &trans_ttbr0, &t0sz, page,
+				  PAGE_KERNEL_ROX);
 	if (rc)
 		return rc;
 
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index b38aae5b488d..de4e9e0ad682 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -141,8 +141,8 @@ int machine_kexec_post_load(struct kimage *kimage)
 	reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start;
 	memcpy(reloc_code, __relocate_new_kernel_start, reloc_size);
 	kimage->arch.kern_reloc = __pa(reloc_code);
-	rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0,
-				  &kimage->arch.t0sz, reloc_code);
+	rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0, &kimage->arch.t0sz,
+				  reloc_code, PAGE_KERNEL_EXEC);
 	if (rc)
 		return rc;
 	kimage->arch.phys_offset = virt_to_phys(kimage) - (long)kimage;
diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c
index 7b14df3c6477..4dfe6a9f9a8b 100644
--- a/arch/arm64/mm/trans_pgd.c
+++ b/arch/arm64/mm/trans_pgd.c
@@ -230,7 +230,7 @@ int trans_pgd_create_copy(struct trans_pgd_info *info, pgd_t **dst_pgdp,
  * maximum T0SZ for this page.
  */
 int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
-			 unsigned long *t0sz, void *page)
+			 unsigned long *t0sz, void *page, pgprot_t prot)
 {
 	phys_addr_t dst_addr = virt_to_phys(page);
 	unsigned long pfn = __phys_to_pfn(dst_addr);
@@ -240,7 +240,7 @@ int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
 	int this_level, index, level_lsb, level_msb;
 
 	dst_addr &= PAGE_MASK;
-	prev_level_entry = pte_val(pfn_pte(pfn, PAGE_KERNEL_ROX));
+	prev_level_entry = pte_val(pfn_pte(pfn, prot));
 
 	for (this_level = 3; this_level >= 0; this_level--) {
 		levels[this_level] = trans_alloc(info);
-- 
2.41.0


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