Commit f8f0d0b6 authored by Steven Price's avatar Steven Price Committed by Linus Torvalds
Browse files

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 45dcd209 ("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: default avatarSteven Price <steven.price@arm.com>
Reviewed-by: default avatarCatalin 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9c7869c7

arch/arm64/mm/dump.c

+3 −3
Original line number Diff line number Diff line
@@ -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,

arch/x86/mm/dump_pagetables.c

+10 −9
Original line number Diff line number Diff line
@@ -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

include/linux/ptdump.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

mm/ptdump.c

+8 −8
Original line number Diff line number Diff line
@@ -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);

}

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