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

Christophe Leroy
2024-01-30T10:37:34Z

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

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
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)