[PATCH v2 4/5] mm: ptdump: Have ptdump_check_wx() return bool

From: Christophe Leroy <hidden>
Date: 2024-01-30 10:36:51
Also in: linux-arm-kernel, linux-mm, linux-riscv, linux-s390, lkml
Subsystem: arm64 port (aarch64 architecture), linux for powerpc (32-bit and 64-bit), memory management - core, risc-v architecture, s390 architecture, the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers: Catalin Marinas, Will Deacon, Madhavan Srinivasan, Michael Ellerman, Andrew Morton, David Hildenbrand, Paul Walmsley, Palmer Dabbelt, Albert Ou, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra

Have ptdump_check_wx() return true when the check is successful
or false otherwise.

Signed-off-by: Christophe Leroy <redacted>
---
v2: New
---
 arch/arm64/mm/ptdump.c          | 11 ++++++++---
 arch/powerpc/mm/ptdump/ptdump.c | 13 +++++++++----
 arch/riscv/mm/ptdump.c          | 11 ++++++++---
 arch/s390/mm/dump_pagetables.c  | 13 +++++++++----
 arch/x86/include/asm/pgtable.h  |  2 +-
 arch/x86/mm/dump_pagetables.c   | 19 ++++++++++++-------
 include/linux/ptdump.h          |  2 +-
 7 files changed, 48 insertions(+), 23 deletions(-)

diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index e305b6593c4e..696822f75582 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c

@@ -345,7 +345,7 @@ static struct ptdump_info kernel_ptdump_info = {
 	.base_addr	= PAGE_OFFSET,
 };
 
-void ptdump_check_wx(void)
+bool ptdump_check_wx(void)
 {
 	struct pg_state st = {
 		.seq = NULL,

@@ -366,11 +366,16 @@ void ptdump_check_wx(void)
 
 	ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
 
-	if (st.wx_pages || st.uxn_pages)
+	if (st.wx_pages || st.uxn_pages) {
 		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
 			st.wx_pages, st.uxn_pages);
-	else
+
+		return false;
+	} else {
 		pr_info("Checked W+X mappings: passed, no W+X pages found\n");
+
+		return true;
+	}
 }
 
 static int __init ptdump_init(void)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index b835c80371cd..9dc239967b77 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c

@@ -327,7 +327,7 @@ static void __init build_pgtable_complete_mask(void)
 				pg_level[i].mask |= pg_level[i].flag[j].mask;
 }
 
-void ptdump_check_wx(void)
+bool ptdump_check_wx(void)
 {
 	struct pg_state st = {
 		.seq = NULL,

@@ -344,15 +344,20 @@ void ptdump_check_wx(void)
 	};
 
 	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !mmu_has_feature(MMU_FTR_KERNEL_RO))
-		return;
+		return true;
 
 	ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
 
-	if (st.wx_pages)
+	if (st.wx_pages) {
 		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
 			st.wx_pages);
-	else
+
+		return false;
+	} else {
 		pr_info("Checked W+X mappings: passed, no W+X pages found\n");
+
+		return true;
+	}
 }
 
 static int __init ptdump_init(void)

diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 075265603313..1289cc6d3700 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c

@@ -335,7 +335,7 @@ static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 	ptdump_walk_pgd(&st.ptdump, pinfo->mm, NULL);
 }
 
-void ptdump_check_wx(void)
+bool ptdump_check_wx(void)
 {
 	struct pg_state st = {
 		.seq = NULL,

@@ -356,11 +356,16 @@ void ptdump_check_wx(void)
 
 	ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
 
-	if (st.wx_pages)
+	if (st.wx_pages) {
 		pr_warn("Checked W+X mappings: failed, %lu W+X pages found\n",
 			st.wx_pages);
-	else
+
+		return false;
+	} else {
 		pr_info("Checked W+X mappings: passed, no W+X pages found\n");
+
+		return true;
+	}
 }
 
 static int ptdump_show(struct seq_file *m, void *v)

diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index 99da5a5602a8..ffd07ed7b4af 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c

@@ -192,7 +192,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 	}
 }
 
-void ptdump_check_wx(void)
+bool ptdump_check_wx(void)
 {
 	struct pg_state st = {
 		.ptdump = {

@@ -215,14 +215,19 @@ void ptdump_check_wx(void)
 	};
 
 	if (!MACHINE_HAS_NX)
-		return;
+		return true;
 	ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
-	if (st.wx_pages)
+	if (st.wx_pages) {
 		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n", st.wx_pages);
-	else
+
+		return false;
+	} else {
 		pr_info("Checked W+X mappings: passed, no %sW+X pages found\n",
 			(nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) ?
 			"unexpected " : "");
+
+		return true;
+	}
 }
 
 #ifdef CONFIG_PTDUMP_DEBUGFS

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 6c979028e521..b50b2ef63672 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h

@@ -31,7 +31,7 @@ struct seq_file;
 void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm);
 void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,
 				   bool user);
-void ptdump_walk_pgd_level_checkwx(void);
+bool ptdump_walk_pgd_level_checkwx(void);
 #define ptdump_check_wx ptdump_walk_pgd_level_checkwx
 void ptdump_walk_user_pgd_level_checkwx(void);

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 0008524eebe9..c58c01f560fd 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c

@@ -362,7 +362,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 	}
 }
 
-static void ptdump_walk_pgd_level_core(struct seq_file *m,
+bool void ptdump_walk_pgd_level_core(struct seq_file *m,
 				       struct mm_struct *mm, pgd_t *pgd,
 				       bool checkwx, bool dmesg)
 {

@@ -391,12 +391,17 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m,
 	ptdump_walk_pgd(&st.ptdump, mm, pgd);
 
 	if (!checkwx)
-		return;
-	if (st.wx_pages)
+		return true;
+	if (st.wx_pages) {
 		pr_info("x86/mm: Checked W+X mappings: FAILED, %lu W+X pages found.\n",
 			st.wx_pages);
-	else
+
+		return false;
+	} else {
 		pr_info("x86/mm: Checked W+X mappings: passed, no W+X pages found.\n");
+
+		return true;
+	}
 }
 
 void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm)

@@ -431,12 +436,12 @@ void ptdump_walk_user_pgd_level_checkwx(void)
 #endif
 }
 
-void ptdump_walk_pgd_level_checkwx(void)
+bool ptdump_walk_pgd_level_checkwx(void)
 {
 	if (!(__supported_pte_mask & _PAGE_NX))
-		return;
+		return true;
 
-	ptdump_walk_pgd_level_core(NULL, &init_mm, INIT_PGD, true, false);
+	return ptdump_walk_pgd_level_core(NULL, &init_mm, INIT_PGD, true, false);
 }
 
 static int __init pt_dump_init(void)

diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index c10513739bf9..953b61696ccf 100644
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h

@@ -19,7 +19,7 @@ struct ptdump_state {
 };
 
 void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd);
-void ptdump_check_wx(void);
+bool ptdump_check_wx(void);
 
 static inline void debug_checkwx(void)
 {

-- 
2.43.0

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