powerpc/ptdump: Dump PXX level info for kernel_page_tables

riteshharjani · maddy-kerneldev · commit 3d44be297e7e · 2025-11-18T12:35:53.000+05:30
This patch adds PGD/PUD/PMD/PTE level information while dumping kernel page tables. Before this patch it was hard to identify which entries belongs to which page table level e.g. ~ # dmesg |grep -i radix [0.000000] radix-mmu: Mapped 0x0000000000000000-0x0000000005400000 with 2.00 MiB pages (exec) [0.000000] radix-mmu: Mapped 0x0000000005400000-0x0000000040000000 with 2.00 MiB pages [0.000000] radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages [0.000000] radix-mmu: Initializing Radix MMU Before: ---[ Start of kernel VM ]--- 0xc000000000000000-0xc000000003ffffff XXX 64M r X pte valid present dirty accessed 0xc000000004000000-0xc00000003fffffff XXX 960M r w pte valid present dirty accessed 0xc000000040000000-0xc0000000ffffffff XXX 3G r w pte valid present dirty accessed ... ---[ vmemmap start ]--- 0xc00c000000000000-0xc00c0000003fffff XXX 4M r w pte valid present dirty accessed After: ---[ Start of kernel VM ]--- 0xc000000000000000-0xc000000003ffffff XXX 64M PMD r X pte valid present dirty accessed 0xc000000004000000-0xc00000003fffffff XXX 960M PMD r w pte valid present dirty accessed 0xc000000040000000-0xc0000000ffffffff XXX 3G PUD r w pte valid present dirty accessed ... ---[ vmemmap start ]--- 0xc00c000000000000-0xc00c0000003fffff XXX 4M PMD r w pte valid present dirty accessed Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/95defb675ee5607ef3923a1e6aeac39311b8fad4.1761834163.git.ritesh.list@gmail.com
diff --git a/arch/powerpc/mm/ptdump/8xx.c b/arch/powerpc/mm/ptdump/8xx.c
@@ -71,18 +71,23 @@ static const struct flag_info flag_array[] = {
 
 struct ptdump_pg_level pg_level[5] = {
 	{ /* pgd */
+		.name	= "PGD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* p4d */
+		.name	= "P4D",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pud */
+		.name	= "PUD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pmd */
+		.name	= "PMD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pte */
+		.name	= "PTE",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	},
diff --git a/arch/powerpc/mm/ptdump/book3s64.c b/arch/powerpc/mm/ptdump/book3s64.c
@@ -104,18 +104,23 @@ static const struct flag_info flag_array[] = {
 
 struct ptdump_pg_level pg_level[5] = {
 	{ /* pgd */
+		.name	= "PGD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* p4d */
+		.name	= "P4D",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pud */
+		.name	= "PUD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pmd */
+		.name	= "PMD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pte */
+		.name	= "PTE",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	},
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
@@ -178,6 +178,7 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
 	pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
 	pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
 	pt_dump_size(st->seq, addr - st->start_address);
+	pt_dump_seq_printf(st->seq, "%s ", pg_level[st->level].name);
 }
 
 static void note_prot_wx(struct pg_state *st, unsigned long addr)
diff --git a/arch/powerpc/mm/ptdump/ptdump.h b/arch/powerpc/mm/ptdump/ptdump.h
@@ -13,6 +13,7 @@ struct flag_info {
 
 struct ptdump_pg_level {
 	const struct flag_info *flag;
+	char name[4];
 	size_t num;
 	u64 mask;
 };
diff --git a/arch/powerpc/mm/ptdump/shared.c b/arch/powerpc/mm/ptdump/shared.c
@@ -69,18 +69,23 @@ static const struct flag_info flag_array[] = {
 
 struct ptdump_pg_level pg_level[5] = {
 	{ /* pgd */
+		.name	= "PGD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* p4d */
+		.name	= "P4D",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pud */
+		.name	= "PUD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pmd */
+		.name	= "PMD",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	}, { /* pte */
+		.name	= "PTE",
 		.flag	= flag_array,
 		.num	= ARRAY_SIZE(flag_array),
 	},

Original file line number	Diff line number	Diff line change
`@@ -178,6 +178,7 @@ static void dump_addr(struct pg_state *st, unsigned long addr)`
`178`	`178`	`pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);`
`179`	`179`	`pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);`
`180`	`180`	`pt_dump_size(st->seq, addr - st->start_address);`
	`181`	`+ pt_dump_seq_printf(st->seq, "%s ", pg_level[st->level].name);`
`181`	`182`	`}`
`182`	`183`
`183`	`184`	`static void note_prot_wx(struct pg_state *st, unsigned long addr)`