[PATCH v2] arm64: ptdump: Support userspace page tables
From: Vincent Whitchurch <hidden>
Date: 2021-10-14 08:14:51
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
The kernel_page_tables debugfs file can be used to examine the page
table entries for mappings in kernel space but there is currently no
easy way to check userspace mappings. /proc/*/pagemap provides some
information but it does not include architecture-specific details such
as the memory type (Normal, Device etc).
Add a user_page_tables debugfs file to dump out the userspace page
tables for the current process. This is enabled by the same config
options as kernel_page_tables.
Signed-off-by: Vincent Whitchurch <redacted>
---
Notes:
v2: Reworded commit message.
arch/arm64/mm/ptdump.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 1c403536c9bb..91a62f07eae2 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c@@ -309,6 +309,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, void ptdump_walk(struct seq_file *s, struct ptdump_info *info) { + struct mm_struct *mm = info->mm ?: current->mm; unsigned long end = ~0UL; struct pg_state st;
@@ -328,7 +329,7 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info) } }; - ptdump_walk_pgd(&st.ptdump, info->mm, NULL); + ptdump_walk_pgd(&st.ptdump, mm, NULL); } static void __init ptdump_initialize(void)
@@ -347,6 +348,16 @@ static struct ptdump_info kernel_ptdump_info = { .base_addr = PAGE_OFFSET, }; +static struct addr_marker user_address_markers[] = { + { 0, "Userspace memory start" }, + { 0 /* TASK_SIZE_64 */, "Userspace memory end" }, + { -1, NULL }, +}; + +static struct ptdump_info user_ptdump_info = { + .markers = user_address_markers, +}; + void ptdump_check_wx(void) { struct pg_state st = {
@@ -381,8 +392,10 @@ static int __init ptdump_init(void) #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START; #endif + user_address_markers[1].start_address = TASK_SIZE_64; ptdump_initialize(); ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); + ptdump_debugfs_register(&user_ptdump_info, "user_page_tables"); return 0; } device_initcall(ptdump_init);
--
2.28.0
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