mm/debug.c - linux/kernel/git/bpf/bpf-next - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * mm/debug.c
  *
  * mm/ specific debug routines.
  *
  */

 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/trace_events.h>
 #include <linux/memcontrol.h>
 #include <trace/events/mmflags.h>
 #include <linux/migrate.h>
 #include <linux/page_owner.h>
 #include <linux/ctype.h>

 #include "internal.h"

 const char *migrate_reason_names[MR_TYPES] = {
 	"compaction",
 	"memory_failure",
 	"memory_hotplug",
 	"syscall_or_cpuset",
 	"mempolicy_mbind",
 	"numa_misplaced",
 	"cma",
 };

 const struct trace_print_flags pageflag_names[] = {
 	__def_pageflag_names,
 	{0, NULL}
 };

 const struct trace_print_flags gfpflag_names[] = {
 	__def_gfpflag_names,
 	{0, NULL}
 };

 const struct trace_print_flags vmaflag_names[] = {
 	__def_vmaflag_names,
 	{0, NULL}
 };

 static void __dump_page(struct page *page)
 {
 	struct page *head = compound_head(page);
 	struct address_space *mapping;
 	bool compound = PageCompound(page);
 	/*
 	 * Accessing the pageblock without the zone lock. It could change to
 	 * "isolate" again in the meantime, but since we are just dumping the
 	 * state for debugging, it should be fine to accept a bit of
 	 * inaccuracy here due to racing.
 	 */
 	bool page_cma = is_migrate_cma_page(page);
 	int mapcount;
 	char *type = "";

 	if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
 		/*
 		 * Corrupt page, so we cannot call page_mapping. Instead, do a
 		 * safe subset of the steps that page_mapping() does. Caution:
 		 * this will be misleading for tail pages, PageSwapCache pages,
 		 * and potentially other situations. (See the page_mapping()
 		 * implementation for what's missing here.)
 		 */
 		unsigned long tmp = (unsigned long)page->mapping;

 		if (tmp & PAGE_MAPPING_ANON)
 			mapping = NULL;
 		else
 			mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
 		head = page;
 		compound = false;
 	} else {
 		mapping = page_mapping(page);
 	}

 	/*
 	 * Avoid VM_BUG_ON() in page_mapcount().
 	 * page->_mapcount space in struct page is used by sl[aou]b pages to
 	 * encode own info.
 	 */
 	mapcount = PageSlab(head) ? 0 : page_mapcount(page);

 	pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
 			page, page_ref_count(head), mapcount, mapping,
 			page_to_pgoff(page), page_to_pfn(page));
 	if (compound) {
 		if (hpage_pincount_available(page)) {
 			pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
 					head, compound_order(head),
 					head_compound_mapcount(head),
 					head_compound_pincount(head));
 		} else {
 			pr_warn("head:%p order:%u compound_mapcount:%d\n",
 					head, compound_order(head),
 					head_compound_mapcount(head));
 		}
 	}

 #ifdef CONFIG_MEMCG
 	if (head->memcg_data)
 		pr_warn("memcg:%lx\n", head->memcg_data);
 #endif
 	if (PageKsm(page))
 		type = "ksm ";
 	else if (PageAnon(page))
 		type = "anon ";
 	else if (mapping) {
 		struct inode *host;
 		const struct address_space_operations *a_ops;
 		struct hlist_node *dentry_first;
 		struct dentry *dentry_ptr;
 		struct dentry dentry;
 		unsigned long ino;

 		/*
 		 * mapping can be invalid pointer and we don't want to crash
 		 * accessing it, so probe everything depending on it carefully
 		 */
 		if (get_kernel_nofault(host, &mapping->host) ||
 		    get_kernel_nofault(a_ops, &mapping->a_ops)) {
 			pr_warn("failed to read mapping contents, not a valid kernel address?\n");
 			goto out_mapping;
 		}

 		if (!host) {
 			pr_warn("aops:%ps\n", a_ops);
 			goto out_mapping;
 		}

 		if (get_kernel_nofault(dentry_first, &host->i_dentry.first) ||
 		    get_kernel_nofault(ino, &host->i_ino)) {
 			pr_warn("aops:%ps with invalid host inode %px\n",
 					a_ops, host);
 			goto out_mapping;
 		}

 		if (!dentry_first) {
 			pr_warn("aops:%ps ino:%lx\n", a_ops, ino);
 			goto out_mapping;
 		}

 		dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
 		if (get_kernel_nofault(dentry, dentry_ptr)) {
 			pr_warn("aops:%ps ino:%lx with invalid dentry %px\n",
 					a_ops, ino, dentry_ptr);
 		} else {
 			/*
 			 * if dentry is corrupted, the %pd handler may still
 			 * crash, but it's unlikely that we reach here with a
 			 * corrupted struct page
 			 */
 			pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n",
 					a_ops, ino, &dentry);
 		}
 	}
 out_mapping:
 	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);

 	pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
 		page_cma ? " CMA" : "");
 	print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
 			sizeof(unsigned long), page,
 			sizeof(struct page), false);
 	if (head != page)
 		print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
 			sizeof(unsigned long), head,
 			sizeof(struct page), false);
 }

 void dump_page(struct page *page, const char *reason)
 {
 	if (PagePoisoned(page))
 		pr_warn("page:%p is uninitialized and poisoned", page);
 	else
 		__dump_page(page);
 	if (reason)
 		pr_warn("page dumped because: %s\n", reason);
 	dump_page_owner(page);
 }
 EXPORT_SYMBOL(dump_page);

 #ifdef CONFIG_DEBUG_VM

 void dump_vma(const struct vm_area_struct *vma)
 {
 	pr_emerg("vma %px start %px end %px\n"
 		"next %px prev %px mm %px\n"
 		"prot %lx anon_vma %px vm_ops %px\n"
 		"pgoff %lx file %px private_data %px\n"
 		"flags: %#lx(%pGv)\n",
 		vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next,
 		vma->vm_prev, vma->vm_mm,
 		(unsigned long)pgprot_val(vma->vm_page_prot),
 		vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
 		vma->vm_file, vma->vm_private_data,
 		vma->vm_flags, &vma->vm_flags);
 }
 EXPORT_SYMBOL(dump_vma);

 void dump_mm(const struct mm_struct *mm)
 {
 	pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
 #ifdef CONFIG_MMU
 		"get_unmapped_area %px\n"
 #endif
 		"mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
 		"pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
 		"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
 		"pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
 		"start_code %lx end_code %lx start_data %lx end_data %lx\n"
 		"start_brk %lx brk %lx start_stack %lx\n"
 		"arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
 		"binfmt %px flags %lx core_state %px\n"
 #ifdef CONFIG_AIO
 		"ioctx_table %px\n"
 #endif
 #ifdef CONFIG_MEMCG
 		"owner %px "
 #endif
 		"exe_file %px\n"
 #ifdef CONFIG_MMU_NOTIFIER
 		"notifier_subscriptions %px\n"
 #endif
 #ifdef CONFIG_NUMA_BALANCING
 		"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
 #endif
 		"tlb_flush_pending %d\n"
 		"def_flags: %#lx(%pGv)\n",

 		mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,
 #ifdef CONFIG_MMU
 		mm->get_unmapped_area,
 #endif
 		mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
 		mm->pgd, atomic_read(&mm->mm_users),
 		atomic_read(&mm->mm_count),
 		mm_pgtables_bytes(mm),
 		mm->map_count,
 		mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
 		(u64)atomic64_read(&mm->pinned_vm),
 		mm->data_vm, mm->exec_vm, mm->stack_vm,
 		mm->start_code, mm->end_code, mm->start_data, mm->end_data,
 		mm->start_brk, mm->brk, mm->start_stack,
 		mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
 		mm->binfmt, mm->flags, mm->core_state,
 #ifdef CONFIG_AIO
 		mm->ioctx_table,
 #endif
 #ifdef CONFIG_MEMCG
 		mm->owner,
 #endif
 		mm->exe_file,
 #ifdef CONFIG_MMU_NOTIFIER
 		mm->notifier_subscriptions,
 #endif
 #ifdef CONFIG_NUMA_BALANCING
 		mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
 #endif
 		atomic_read(&mm->tlb_flush_pending),
 		mm->def_flags, &mm->def_flags
 	);
 }

 static bool page_init_poisoning __read_mostly = true;

 static int __init setup_vm_debug(char *str)
 {
 	bool __page_init_poisoning = true;

 	/*
 	 * Calling vm_debug with no arguments is equivalent to requesting
 	 * to enable all debugging options we can control.
 	 */
 	if (*str++ != '=' || !*str)
 		goto out;

 	__page_init_poisoning = false;
 	if (*str == '-')
 		goto out;

 	while (*str) {
 		switch (tolower(*str)) {
 		case'p':
 			__page_init_poisoning = true;
 			break;
 		default:
 			pr_err("vm_debug option '%c' unknown. skipped\n",
 			       *str);
 		}

 		str++;
 	}
 out:
 	if (page_init_poisoning && !__page_init_poisoning)
 		pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");

 	page_init_poisoning = __page_init_poisoning;

 	return 1;
 }
 __setup("vm_debug", setup_vm_debug);

 void page_init_poison(struct page *page, size_t size)
 {
 	if (page_init_poisoning)
 		memset(page, PAGE_POISON_PATTERN, size);
 }
 EXPORT_SYMBOL_GPL(page_init_poison);
 #endif		/* CONFIG_DEBUG_VM */
	// SPDX-License-Identifier: GPL-2.0
	/*
	* mm/debug.c
	*
	* mm/ specific debug routines.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/trace_events.h>
	#include <linux/memcontrol.h>
	#include <trace/events/mmflags.h>
	#include <linux/migrate.h>
	#include <linux/page_owner.h>
	#include <linux/ctype.h>

	#include "internal.h"

	const char *migrate_reason_names[MR_TYPES] = {
	"compaction",
	"memory_failure",
	"memory_hotplug",
	"syscall_or_cpuset",
	"mempolicy_mbind",
	"numa_misplaced",
	"cma",
	};

	const struct trace_print_flags pageflag_names[] = {
	__def_pageflag_names,
	{0, NULL}
	};

	const struct trace_print_flags gfpflag_names[] = {
	__def_gfpflag_names,
	{0, NULL}
	};

	const struct trace_print_flags vmaflag_names[] = {
	__def_vmaflag_names,
	{0, NULL}
	};

	static void __dump_page(struct page *page)
	{
	struct page *head = compound_head(page);
	struct address_space *mapping;
	bool compound = PageCompound(page);
	/*
	* Accessing the pageblock without the zone lock. It could change to
	* "isolate" again in the meantime, but since we are just dumping the
	* state for debugging, it should be fine to accept a bit of
	* inaccuracy here due to racing.
	*/
	bool page_cma = is_migrate_cma_page(page);
	int mapcount;
	char *type = "";

	if (page < head \|\| (page >= head + MAX_ORDER_NR_PAGES)) {
	/*
	* Corrupt page, so we cannot call page_mapping. Instead, do a
	* safe subset of the steps that page_mapping() does. Caution:
	* this will be misleading for tail pages, PageSwapCache pages,
	* and potentially other situations. (See the page_mapping()
	* implementation for what's missing here.)
	*/
	unsigned long tmp = (unsigned long)page->mapping;

	if (tmp & PAGE_MAPPING_ANON)
	mapping = NULL;
	else
	mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS);
	head = page;
	compound = false;
	} else {
	mapping = page_mapping(page);
	}

	/*
	* Avoid VM_BUG_ON() in page_mapcount().
	* page->_mapcount space in struct page is used by sl[aou]b pages to
	* encode own info.
	*/
	mapcount = PageSlab(head) ? 0 : page_mapcount(page);

	pr_warn("page:%p refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n",
	page, page_ref_count(head), mapcount, mapping,
	page_to_pgoff(page), page_to_pfn(page));
	if (compound) {
	if (hpage_pincount_available(page)) {
	pr_warn("head:%p order:%u compound_mapcount:%d compound_pincount:%d\n",
	head, compound_order(head),
	head_compound_mapcount(head),
	head_compound_pincount(head));
	} else {
	pr_warn("head:%p order:%u compound_mapcount:%d\n",
	head, compound_order(head),
	head_compound_mapcount(head));
	}
	}

	#ifdef CONFIG_MEMCG
	if (head->memcg_data)
	pr_warn("memcg:%lx\n", head->memcg_data);
	#endif
	if (PageKsm(page))
	type = "ksm ";
	else if (PageAnon(page))
	type = "anon ";
	else if (mapping) {
	struct inode *host;
	const struct address_space_operations *a_ops;
	struct hlist_node *dentry_first;
	struct dentry *dentry_ptr;
	struct dentry dentry;
	unsigned long ino;

	/*
	* mapping can be invalid pointer and we don't want to crash
	* accessing it, so probe everything depending on it carefully
	*/
	if (get_kernel_nofault(host, &mapping->host) \|\|
	get_kernel_nofault(a_ops, &mapping->a_ops)) {
	pr_warn("failed to read mapping contents, not a valid kernel address?\n");
	goto out_mapping;
	}

	if (!host) {
	pr_warn("aops:%ps\n", a_ops);
	goto out_mapping;
	}

	if (get_kernel_nofault(dentry_first, &host->i_dentry.first) \|\|
	get_kernel_nofault(ino, &host->i_ino)) {
	pr_warn("aops:%ps with invalid host inode %px\n",
	a_ops, host);
	goto out_mapping;
	}

	if (!dentry_first) {
	pr_warn("aops:%ps ino:%lx\n", a_ops, ino);
	goto out_mapping;
	}

	dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias);
	if (get_kernel_nofault(dentry, dentry_ptr)) {
	pr_warn("aops:%ps ino:%lx with invalid dentry %px\n",
	a_ops, ino, dentry_ptr);
	} else {
	/*
	* if dentry is corrupted, the %pd handler may still
	* crash, but it's unlikely that we reach here with a
	* corrupted struct page
	*/
	pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n",
	a_ops, ino, &dentry);
	}
	}
	out_mapping:
	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);

	pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
	page_cma ? " CMA" : "");
	print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
	sizeof(unsigned long), page,
	sizeof(struct page), false);
	if (head != page)
	print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
	sizeof(unsigned long), head,
	sizeof(struct page), false);
	}

	void dump_page(struct page page, const char reason)
	{
	if (PagePoisoned(page))
	pr_warn("page:%p is uninitialized and poisoned", page);
	else
	__dump_page(page);
	if (reason)
	pr_warn("page dumped because: %s\n", reason);
	dump_page_owner(page);
	}
	EXPORT_SYMBOL(dump_page);

	#ifdef CONFIG_DEBUG_VM

	void dump_vma(const struct vm_area_struct *vma)
	{
	pr_emerg("vma %px start %px end %px\n"
	"next %px prev %px mm %px\n"
	"prot %lx anon_vma %px vm_ops %px\n"
	"pgoff %lx file %px private_data %px\n"
	"flags: %#lx(%pGv)\n",
	vma, (void )vma->vm_start, (void )vma->vm_end, vma->vm_next,
	vma->vm_prev, vma->vm_mm,
	(unsigned long)pgprot_val(vma->vm_page_prot),
	vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
	vma->vm_file, vma->vm_private_data,
	vma->vm_flags, &vma->vm_flags);
	}
	EXPORT_SYMBOL(dump_vma);

	void dump_mm(const struct mm_struct *mm)
	{
	pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
	#ifdef CONFIG_MMU
	"get_unmapped_area %px\n"
	#endif
	"mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
	"pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
	"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
	"pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
	"start_code %lx end_code %lx start_data %lx end_data %lx\n"
	"start_brk %lx brk %lx start_stack %lx\n"
	"arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
	"binfmt %px flags %lx core_state %px\n"
	#ifdef CONFIG_AIO
	"ioctx_table %px\n"
	#endif
	#ifdef CONFIG_MEMCG
	"owner %px "
	#endif
	"exe_file %px\n"
	#ifdef CONFIG_MMU_NOTIFIER
	"notifier_subscriptions %px\n"
	#endif
	#ifdef CONFIG_NUMA_BALANCING
	"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
	#endif
	"tlb_flush_pending %d\n"
	"def_flags: %#lx(%pGv)\n",

	mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,
	#ifdef CONFIG_MMU
	mm->get_unmapped_area,
	#endif
	mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
	mm->pgd, atomic_read(&mm->mm_users),
	atomic_read(&mm->mm_count),
	mm_pgtables_bytes(mm),
	mm->map_count,
	mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
	(u64)atomic64_read(&mm->pinned_vm),
	mm->data_vm, mm->exec_vm, mm->stack_vm,
	mm->start_code, mm->end_code, mm->start_data, mm->end_data,
	mm->start_brk, mm->brk, mm->start_stack,
	mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
	mm->binfmt, mm->flags, mm->core_state,
	#ifdef CONFIG_AIO
	mm->ioctx_table,
	#endif
	#ifdef CONFIG_MEMCG
	mm->owner,
	#endif
	mm->exe_file,
	#ifdef CONFIG_MMU_NOTIFIER
	mm->notifier_subscriptions,
	#endif
	#ifdef CONFIG_NUMA_BALANCING
	mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
	#endif
	atomic_read(&mm->tlb_flush_pending),
	mm->def_flags, &mm->def_flags
	);
	}

	static bool page_init_poisoning __read_mostly = true;

	static int __init setup_vm_debug(char *str)
	{
	bool __page_init_poisoning = true;

	/*
	* Calling vm_debug with no arguments is equivalent to requesting
	* to enable all debugging options we can control.
	*/
	if (str++ != '=' \|\| !str)
	goto out;

	__page_init_poisoning = false;
	if (*str == '-')
	goto out;

	while (*str) {
	switch (tolower(*str)) {
	case'p':
	__page_init_poisoning = true;
	break;
	default:
	pr_err("vm_debug option '%c' unknown. skipped\n",
	*str);
	}

	str++;
	}
	out:
	if (page_init_poisoning && !__page_init_poisoning)
	pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");

	page_init_poisoning = __page_init_poisoning;

	return 1;
	}
	__setup("vm_debug", setup_vm_debug);

	void page_init_poison(struct page *page, size_t size)
	{
	if (page_init_poisoning)
	memset(page, PAGE_POISON_PATTERN, size);
	}
	EXPORT_SYMBOL_GPL(page_init_poison);
	#endif /* CONFIG_DEBUG_VM */