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authorSteven Price <steven.price@arm.com>2020-02-03 17:36:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-04 03:05:25 +0000
commitf8f0d0b6fa203bfa363d30f34f6fecce9e5cc2f7 (patch)
tree3e731fbe428f47df48ef8170d1b92ace3a93119a
parent9c7869c7f1720855f90e5bf15539939738d18cb9 (diff)
mm: ptdump: reduce level numbers by 1 in note_page()
Rather than having to increment the 'depth' number by 1 in ptdump_hole(), let's change the meaning of 'level' in note_page() since that makes the code simplier. Note that for x86, the level numbers were previously increased by 1 in commit 45dcd2091363 ("x86/mm/dump_pagetables: Fix printout of p4d level") and the comment "Bit 7 has a different meaning" was not updated, so this change also makes the code match the comment again. Link: http://lkml.kernel.org/r/20191218162402.45610-24-steven.price@arm.com Signed-off-by: Steven Price <steven.price@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Liang, Kan" <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Zong Li <zong.li@sifive.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm64/mm/dump.c6
-rw-r--r--arch/x86/mm/dump_pagetables.c19
-rw-r--r--include/linux/ptdump.h1
-rw-r--r--mm/ptdump.c16
4 files changed, 22 insertions, 20 deletions
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index e5b6691c5bfc..ef4b3ca1e058 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -176,8 +176,7 @@ struct pg_level {
};
static struct pg_level pg_level[] = {
- {
- }, { /* pgd */
+ { /* pgd */
.name = "PGD",
.bits = pte_bits,
.num = ARRAY_SIZE(pte_bits),
@@ -257,7 +256,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
if (level >= 0)
prot = val & pg_level[level].mask;
- if (!st->level) {
+ if (st->level == -1) {
st->level = level;
st->current_prot = prot;
st->start_address = addr;
@@ -351,6 +350,7 @@ void ptdump_check_wx(void)
{ 0, NULL},
{ -1, NULL},
},
+ .level = -1,
.check_wx = true,
.ptdump = {
.note_page = note_page,
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index a0b8ffc927bb..411f6a758998 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -180,7 +180,7 @@ static struct addr_marker address_markers[] = {
static void printk_prot(struct seq_file *m, pgprotval_t pr, int level, bool dmsg)
{
static const char * const level_name[] =
- { "cr3", "pgd", "p4d", "pud", "pmd", "pte" };
+ { "pgd", "p4d", "pud", "pmd", "pte" };
if (!(pr & _PAGE_PRESENT)) {
/* Not present */
@@ -204,12 +204,12 @@ static void printk_prot(struct seq_file *m, pgprotval_t pr, int level, bool dmsg
pt_dump_cont_printf(m, dmsg, " ");
/* Bit 7 has a different meaning on level 3 vs 4 */
- if (level <= 4 && pr & _PAGE_PSE)
+ if (level <= 3 && pr & _PAGE_PSE)
pt_dump_cont_printf(m, dmsg, "PSE ");
else
pt_dump_cont_printf(m, dmsg, " ");
- if ((level == 5 && pr & _PAGE_PAT) ||
- ((level == 4 || level == 3) && pr & _PAGE_PAT_LARGE))
+ if ((level == 4 && pr & _PAGE_PAT) ||
+ ((level == 3 || level == 2) && pr & _PAGE_PAT_LARGE))
pt_dump_cont_printf(m, dmsg, "PAT ");
else
pt_dump_cont_printf(m, dmsg, " ");
@@ -271,15 +271,15 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
new_prot = val & PTE_FLAGS_MASK;
- if (level > 1) {
- new_eff = effective_prot(st->prot_levels[level - 2],
+ if (level > 0) {
+ new_eff = effective_prot(st->prot_levels[level - 1],
new_prot);
} else {
new_eff = new_prot;
}
- if (level > 0)
- st->prot_levels[level - 1] = new_eff;
+ if (level >= 0)
+ st->prot_levels[level] = new_eff;
/*
* If we have a "break" in the series, we need to flush the state that
@@ -289,7 +289,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
cur = st->current_prot;
eff = st->effective_prot;
- if (!st->level) {
+ if (st->level == -1) {
/* First entry */
st->current_prot = new_prot;
st->effective_prot = new_eff;
@@ -380,6 +380,7 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
.note_page = note_page,
.range = ptdump_ranges
},
+ .level = -1,
.to_dmesg = dmesg,
.check_wx = checkwx,
.seq = m
diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index a0fb8dd2be97..b28f3f2acf90 100644
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h
@@ -11,6 +11,7 @@ struct ptdump_range {
};
struct ptdump_state {
+ /* level is 0:PGD to 4:PTE, or -1 if unknown */
void (*note_page)(struct ptdump_state *st, unsigned long addr,
int level, unsigned long val);
const struct ptdump_range *range;
diff --git a/mm/ptdump.c b/mm/ptdump.c
index 868638b8e404..ad18a9839d6f 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -17,7 +17,7 @@ static inline int note_kasan_page_table(struct mm_walk *walk,
{
struct ptdump_state *st = walk->private;
- st->note_page(st, addr, 5, pte_val(kasan_early_shadow_pte[0]));
+ st->note_page(st, addr, 4, pte_val(kasan_early_shadow_pte[0]));
walk->action = ACTION_CONTINUE;
@@ -37,7 +37,7 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
#endif
if (pgd_leaf(val))
- st->note_page(st, addr, 1, pgd_val(val));
+ st->note_page(st, addr, 0, pgd_val(val));
return 0;
}
@@ -54,7 +54,7 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
#endif
if (p4d_leaf(val))
- st->note_page(st, addr, 2, p4d_val(val));
+ st->note_page(st, addr, 1, p4d_val(val));
return 0;
}
@@ -71,7 +71,7 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
#endif
if (pud_leaf(val))
- st->note_page(st, addr, 3, pud_val(val));
+ st->note_page(st, addr, 2, pud_val(val));
return 0;
}
@@ -88,7 +88,7 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
#endif
if (pmd_leaf(val))
- st->note_page(st, addr, 4, pmd_val(val));
+ st->note_page(st, addr, 3, pmd_val(val));
return 0;
}
@@ -98,7 +98,7 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
{
struct ptdump_state *st = walk->private;
- st->note_page(st, addr, 5, pte_val(READ_ONCE(*pte)));
+ st->note_page(st, addr, 4, pte_val(READ_ONCE(*pte)));
return 0;
}
@@ -108,7 +108,7 @@ static int ptdump_hole(unsigned long addr, unsigned long next,
{
struct ptdump_state *st = walk->private;
- st->note_page(st, addr, depth + 1, 0);
+ st->note_page(st, addr, depth, 0);
return 0;
}
@@ -135,5 +135,5 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm)
up_read(&mm->mmap_sem);
/* Flush out the last page */
- st->note_page(st, 0, 0, 0);
+ st->note_page(st, 0, -1, 0);
}