Fixed MTP to work with TWRP

fs/proc/kcore.c

@@ -0,0 +1,644 @@
+/*
+ *	fs/proc/kcore.c kernel ELF core dumper
+ *
+ *	Modelled on fs/exec.c:aout_core_dump()
+ *	Jeremy Fitzhardinge <jeremy@sw.oz.au>
+ *	ELF version written by David Howells <David.Howells@nexor.co.uk>
+ *	Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com>
+ *	Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com>
+ *	Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/proc_fs.h>
+#include <linux/kcore.h>
+#include <linux/user.h>
+#include <linux/capability.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/notifier.h>
+#include <linux/vmalloc.h>
+#include <linux/highmem.h>
+#include <linux/printk.h>
+#include <linux/bootmem.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <linux/list.h>
+#include <linux/ioport.h>
+#include <linux/memory.h>
+#include <asm/sections.h>
+#include "internal.h"
+
+#define CORE_STR "CORE"
+
+#ifndef ELF_CORE_EFLAGS
+#define ELF_CORE_EFLAGS	0
+#endif
+
+static struct proc_dir_entry *proc_root_kcore;
+
+
+#ifndef kc_vaddr_to_offset
+#define	kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
+#endif
+#ifndef	kc_offset_to_vaddr
+#define	kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET)
+#endif
+
+/* An ELF note in memory */
+struct memelfnote
+{
+	const char *name;
+	int type;
+	unsigned int datasz;
+	void *data;
+};
+
+static LIST_HEAD(kclist_head);
+static DEFINE_RWLOCK(kclist_lock);
+static int kcore_need_update = 1;
+
+void
+kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
+{
+	new->addr = (unsigned long)addr;
+	new->size = size;
+	new->type = type;
+
+	write_lock(&kclist_lock);
+	list_add_tail(&new->list, &kclist_head);
+	write_unlock(&kclist_lock);
+}
+
+static size_t get_kcore_size(int *nphdr, size_t *elf_buflen)
+{
+	size_t try, size;
+	struct kcore_list *m;
+
+	*nphdr = 1; /* PT_NOTE */
+	size = 0;
+
+	list_for_each_entry(m, &kclist_head, list) {
+		try = kc_vaddr_to_offset((size_t)m->addr + m->size);
+		if (try > size)
+			size = try;
+		*nphdr = *nphdr + 1;
+	}
+	*elf_buflen =	sizeof(struct elfhdr) + 
+			(*nphdr + 2)*sizeof(struct elf_phdr) + 
+			3 * ((sizeof(struct elf_note)) +
+			     roundup(sizeof(CORE_STR), 4)) +
+			roundup(sizeof(struct elf_prstatus), 4) +
+			roundup(sizeof(struct elf_prpsinfo), 4) +
+			roundup(sizeof(struct task_struct), 4);
+	*elf_buflen = PAGE_ALIGN(*elf_buflen);
+	return size + *elf_buflen;
+}
+
+static void free_kclist_ents(struct list_head *head)
+{
+	struct kcore_list *tmp, *pos;
+
+	list_for_each_entry_safe(pos, tmp, head, list) {
+		list_del(&pos->list);
+		kfree(pos);
+	}
+}
+/*
+ * Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list.
+ */
+static void __kcore_update_ram(struct list_head *list)
+{
+	int nphdr;
+	size_t size;
+	struct kcore_list *tmp, *pos;
+	LIST_HEAD(garbage);
+
+	write_lock(&kclist_lock);
+	if (kcore_need_update) {
+		list_for_each_entry_safe(pos, tmp, &kclist_head, list) {
+			if (pos->type == KCORE_RAM
+				|| pos->type == KCORE_VMEMMAP)
+				list_move(&pos->list, &garbage);
+		}
+		list_splice_tail(list, &kclist_head);
+	} else
+		list_splice(list, &garbage);
+	kcore_need_update = 0;
+	proc_root_kcore->size = get_kcore_size(&nphdr, &size);
+	write_unlock(&kclist_lock);
+
+	free_kclist_ents(&garbage);
+}
+
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * If no highmem, we can assume [0...max_low_pfn) continuous range of memory
+ * because memory hole is not as big as !HIGHMEM case.
+ * (HIGHMEM is special because part of memory is _invisible_ from the kernel.)
+ */
+static int kcore_update_ram(void)
+{
+	LIST_HEAD(head);
+	struct kcore_list *ent;
+	int ret = 0;
+
+	ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+	if (!ent)
+		return -ENOMEM;
+	ent->addr = (unsigned long)__va(0);
+	ent->size = max_low_pfn << PAGE_SHIFT;
+	ent->type = KCORE_RAM;
+	list_add(&ent->list, &head);
+	__kcore_update_ram(&head);
+	return ret;
+}
+
+#else /* !CONFIG_HIGHMEM */
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/* calculate vmemmap's address from given system ram pfn and register it */
+static int
+get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
+{
+	unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT;
+	unsigned long nr_pages = ent->size >> PAGE_SHIFT;
+	unsigned long start, end;
+	struct kcore_list *vmm, *tmp;
+
+
+	start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK;
+	end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1;
+	end = PAGE_ALIGN(end);
+	/* overlap check (because we have to align page */
+	list_for_each_entry(tmp, head, list) {
+		if (tmp->type != KCORE_VMEMMAP)
+			continue;
+		if (start < tmp->addr + tmp->size)
+			if (end > tmp->addr)
+				end = tmp->addr;
+	}
+	if (start < end) {
+		vmm = kmalloc(sizeof(*vmm), GFP_KERNEL);
+		if (!vmm)
+			return 0;
+		vmm->addr = start;
+		vmm->size = end - start;
+		vmm->type = KCORE_VMEMMAP;
+		list_add_tail(&vmm->list, head);
+	}
+	return 1;
+
+}
+#else
+static int
+get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
+{
+	return 1;
+}
+
+#endif
+
+static int
+kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+	struct list_head *head = (struct list_head *)arg;
+	struct kcore_list *ent;
+
+	ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+	if (!ent)
+		return -ENOMEM;
+	ent->addr = (unsigned long)__va((pfn << PAGE_SHIFT));
+	ent->size = nr_pages << PAGE_SHIFT;
+
+	/* Sanity check: Can happen in 32bit arch...maybe */
+	if (ent->addr < (unsigned long) __va(0))
+		goto free_out;
+
+	/* cut not-mapped area. ....from ppc-32 code. */
+	if (ULONG_MAX - ent->addr < ent->size)
+		ent->size = ULONG_MAX - ent->addr;
+
+	/* cut when vmalloc() area is higher than direct-map area */
+	if (VMALLOC_START > (unsigned long)__va(0)) {
+		if (ent->addr > VMALLOC_START)
+			goto free_out;
+		if (VMALLOC_START - ent->addr < ent->size)
+			ent->size = VMALLOC_START - ent->addr;
+	}
+
+	ent->type = KCORE_RAM;
+	list_add_tail(&ent->list, head);
+
+	if (!get_sparsemem_vmemmap_info(ent, head)) {
+		list_del(&ent->list);
+		goto free_out;
+	}
+
+	return 0;
+free_out:
+	kfree(ent);
+	return 1;
+}
+
+static int kcore_update_ram(void)
+{
+	int nid, ret;
+	unsigned long end_pfn;
+	LIST_HEAD(head);
+
+	/* Not inialized....update now */
+	/* find out "max pfn" */
+	end_pfn = 0;
+	for_each_node_state(nid, N_MEMORY) {
+		unsigned long node_end;
+		node_end = node_end_pfn(nid);
+		if (end_pfn < node_end)
+			end_pfn = node_end;
+	}
+	/* scan 0 to max_pfn */
+	ret = walk_system_ram_range(0, end_pfn, &head, kclist_add_private);
+	if (ret) {
+		free_kclist_ents(&head);
+		return -ENOMEM;
+	}
+	__kcore_update_ram(&head);
+	return ret;
+}
+#endif /* CONFIG_HIGHMEM */
+
+/*****************************************************************************/
+/*
+ * determine size of ELF note
+ */
+static int notesize(struct memelfnote *en)
+{
+	int sz;
+
+	sz = sizeof(struct elf_note);
+	sz += roundup((strlen(en->name) + 1), 4);
+	sz += roundup(en->datasz, 4);
+
+	return sz;
+} /* end notesize() */
+
+/*****************************************************************************/
+/*
+ * store a note in the header buffer
+ */
+static char *storenote(struct memelfnote *men, char *bufp)
+{
+	struct elf_note en;
+
+#define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
+
+	en.n_namesz = strlen(men->name) + 1;
+	en.n_descsz = men->datasz;
+	en.n_type = men->type;
+
+	DUMP_WRITE(&en, sizeof(en));
+	DUMP_WRITE(men->name, en.n_namesz);
+
+	/* XXX - cast from long long to long to avoid need for libgcc.a */
+	bufp = (char*) roundup((unsigned long)bufp,4);
+	DUMP_WRITE(men->data, men->datasz);
+	bufp = (char*) roundup((unsigned long)bufp,4);
+
+#undef DUMP_WRITE
+
+	return bufp;
+} /* end storenote() */
+
+/*
+ * store an ELF coredump header in the supplied buffer
+ * nphdr is the number of elf_phdr to insert
+ */
+static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
+{
+	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
+	struct elf_prpsinfo prpsinfo;	/* NT_PRPSINFO */
+	struct elf_phdr *nhdr, *phdr;
+	struct elfhdr *elf;
+	struct memelfnote notes[3];
+	off_t offset = 0;
+	struct kcore_list *m;
+
+	/* setup ELF header */
+	elf = (struct elfhdr *) bufp;
+	bufp += sizeof(struct elfhdr);
+	offset += sizeof(struct elfhdr);
+	memcpy(elf->e_ident, ELFMAG, SELFMAG);
+	elf->e_ident[EI_CLASS]	= ELF_CLASS;
+	elf->e_ident[EI_DATA]	= ELF_DATA;
+	elf->e_ident[EI_VERSION]= EV_CURRENT;
+	elf->e_ident[EI_OSABI] = ELF_OSABI;
+	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+	elf->e_type	= ET_CORE;
+	elf->e_machine	= ELF_ARCH;
+	elf->e_version	= EV_CURRENT;
+	elf->e_entry	= 0;
+	elf->e_phoff	= sizeof(struct elfhdr);
+	elf->e_shoff	= 0;
+	elf->e_flags	= ELF_CORE_EFLAGS;
+	elf->e_ehsize	= sizeof(struct elfhdr);
+	elf->e_phentsize= sizeof(struct elf_phdr);
+	elf->e_phnum	= nphdr;
+	elf->e_shentsize= 0;
+	elf->e_shnum	= 0;
+	elf->e_shstrndx	= 0;
+
+	/* setup ELF PT_NOTE program header */
+	nhdr = (struct elf_phdr *) bufp;
+	bufp += sizeof(struct elf_phdr);
+	offset += sizeof(struct elf_phdr);
+	nhdr->p_type	= PT_NOTE;
+	nhdr->p_offset	= 0;
+	nhdr->p_vaddr	= 0;
+	nhdr->p_paddr	= 0;
+	nhdr->p_filesz	= 0;
+	nhdr->p_memsz	= 0;
+	nhdr->p_flags	= 0;
+	nhdr->p_align	= 0;
+
+	/* setup ELF PT_LOAD program header for every area */
+	list_for_each_entry(m, &kclist_head, list) {
+		phdr = (struct elf_phdr *) bufp;
+		bufp += sizeof(struct elf_phdr);
+		offset += sizeof(struct elf_phdr);
+
+		phdr->p_type	= PT_LOAD;
+		phdr->p_flags	= PF_R|PF_W|PF_X;
+		phdr->p_offset	= kc_vaddr_to_offset(m->addr) + dataoff;
+		phdr->p_vaddr	= (size_t)m->addr;
+		phdr->p_paddr	= 0;
+		phdr->p_filesz	= phdr->p_memsz	= m->size;
+		phdr->p_align	= PAGE_SIZE;
+	}
+
+	/*
+	 * Set up the notes in similar form to SVR4 core dumps made
+	 * with info from their /proc.
+	 */
+	nhdr->p_offset	= offset;
+
+	/* set up the process status */
+	notes[0].name = CORE_STR;
+	notes[0].type = NT_PRSTATUS;
+	notes[0].datasz = sizeof(struct elf_prstatus);
+	notes[0].data = &prstatus;
+
+	memset(&prstatus, 0, sizeof(struct elf_prstatus));
+
+	nhdr->p_filesz	= notesize(&notes[0]);
+	bufp = storenote(&notes[0], bufp);
+
+	/* set up the process info */
+	notes[1].name	= CORE_STR;
+	notes[1].type	= NT_PRPSINFO;
+	notes[1].datasz	= sizeof(struct elf_prpsinfo);
+	notes[1].data	= &prpsinfo;
+
+	memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo));
+	prpsinfo.pr_state	= 0;
+	prpsinfo.pr_sname	= 'R';
+	prpsinfo.pr_zomb	= 0;
+
+	strcpy(prpsinfo.pr_fname, "vmlinux");
+	strlcpy(prpsinfo.pr_psargs, saved_command_line, sizeof(prpsinfo.pr_psargs));
+
+	nhdr->p_filesz	+= notesize(&notes[1]);
+	bufp = storenote(&notes[1], bufp);
+
+	/* set up the task structure */
+	notes[2].name	= CORE_STR;
+	notes[2].type	= NT_TASKSTRUCT;
+	notes[2].datasz	= sizeof(struct task_struct);
+	notes[2].data	= current;
+
+	nhdr->p_filesz	+= notesize(&notes[2]);
+	bufp = storenote(&notes[2], bufp);
+
+} /* end elf_kcore_store_hdr() */
+
+/*****************************************************************************/
+/*
+ * read from the ELF header and then kernel memory
+ */
+static ssize_t
+read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
+{
+	ssize_t acc = 0;
+	size_t size, tsz;
+	size_t elf_buflen;
+	int nphdr;
+	unsigned long start;
+
+	read_lock(&kclist_lock);
+	size = get_kcore_size(&nphdr, &elf_buflen);
+
+	if (buflen == 0 || *fpos >= size) {
+		read_unlock(&kclist_lock);
+		return 0;
+	}
+
+	/* trim buflen to not go beyond EOF */
+	if (buflen > size - *fpos)
+		buflen = size - *fpos;
+
+	/* construct an ELF core header if we'll need some of it */
+	if (*fpos < elf_buflen) {
+		char * elf_buf;
+
+		tsz = elf_buflen - *fpos;
+		if (buflen < tsz)
+			tsz = buflen;
+		elf_buf = kzalloc(elf_buflen, GFP_ATOMIC);
+		if (!elf_buf) {
+			read_unlock(&kclist_lock);
+			return -ENOMEM;
+		}
+		elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen);
+		read_unlock(&kclist_lock);
+		if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
+			kfree(elf_buf);
+			return -EFAULT;
+		}
+		kfree(elf_buf);
+		buflen -= tsz;
+		*fpos += tsz;
+		buffer += tsz;
+		acc += tsz;
+
+		/* leave now if filled buffer already */
+		if (buflen == 0)
+			return acc;
+	} else
+		read_unlock(&kclist_lock);
+
+	/*
+	 * Check to see if our file offset matches with any of
+	 * the addresses in the elf_phdr on our list.
+	 */
+	start = kc_offset_to_vaddr(*fpos - elf_buflen);
+	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
+		tsz = buflen;
+		
+	while (buflen) {
+		struct kcore_list *m;
+
+		read_lock(&kclist_lock);
+		list_for_each_entry(m, &kclist_head, list) {
+			if (start >= m->addr && start < (m->addr+m->size))
+				break;
+		}
+		read_unlock(&kclist_lock);
+
+		if (&m->list == &kclist_head) {
+			if (clear_user(buffer, tsz))
+				return -EFAULT;
+		} else if (is_vmalloc_or_module_addr((void *)start)) {
+			char * elf_buf;
+
+			elf_buf = kzalloc(tsz, GFP_KERNEL);
+			if (!elf_buf)
+				return -ENOMEM;
+			vread(elf_buf, (char *)start, tsz);
+			/* we have to zero-fill user buffer even if no read */
+			if (copy_to_user(buffer, elf_buf, tsz)) {
+				kfree(elf_buf);
+				return -EFAULT;
+			}
+			kfree(elf_buf);
+		} else {
+			if (kern_addr_valid(start)) {
+				unsigned long n;
+
+				n = copy_to_user(buffer, (char *)start, tsz);
+				/*
+				 * We cannot distinguish between fault on source
+				 * and fault on destination. When this happens
+				 * we clear too and hope it will trigger the
+				 * EFAULT again.
+				 */
+				if (n) { 
+					if (clear_user(buffer + tsz - n,
+								n))
+						return -EFAULT;
+				}
+			} else {
+				if (clear_user(buffer, tsz))
+					return -EFAULT;
+			}
+		}
+		buflen -= tsz;
+		*fpos += tsz;
+		buffer += tsz;
+		acc += tsz;
+		start += tsz;
+		tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
+	}
+
+	return acc;
+}
+
+
+static int open_kcore(struct inode *inode, struct file *filp)
+{
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+	if (kcore_need_update)
+		kcore_update_ram();
+	if (i_size_read(inode) != proc_root_kcore->size) {
+		mutex_lock(&inode->i_mutex);
+		i_size_write(inode, proc_root_kcore->size);
+		mutex_unlock(&inode->i_mutex);
+	}
+	return 0;
+}
+
+
+static const struct file_operations proc_kcore_operations = {
+	.read		= read_kcore,
+	.open		= open_kcore,
+	.llseek		= default_llseek,
+};
+
+/* just remember that we have to update kcore */
+static int __meminit kcore_callback(struct notifier_block *self,
+				    unsigned long action, void *arg)
+{
+	switch (action) {
+	case MEM_ONLINE:
+	case MEM_OFFLINE:
+		write_lock(&kclist_lock);
+		kcore_need_update = 1;
+		write_unlock(&kclist_lock);
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block kcore_callback_nb __meminitdata = {
+	.notifier_call = kcore_callback,
+	.priority = 0,
+};
+
+static struct kcore_list kcore_vmalloc;
+
+#ifdef CONFIG_ARCH_PROC_KCORE_TEXT
+static struct kcore_list kcore_text;
+/*
+ * If defined, special segment is used for mapping kernel text instead of
+ * direct-map area. We need to create special TEXT section.
+ */
+static void __init proc_kcore_text_init(void)
+{
+	kclist_add(&kcore_text, _text, _end - _text, KCORE_TEXT);
+}
+#else
+static void __init proc_kcore_text_init(void)
+{
+}
+#endif
+
+#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
+/*
+ * MODULES_VADDR has no intersection with VMALLOC_ADDR.
+ */
+struct kcore_list kcore_modules;
+static void __init add_modules_range(void)
+{
+	if (MODULES_VADDR != VMALLOC_START && MODULES_END != VMALLOC_END) {
+		kclist_add(&kcore_modules, (void *)MODULES_VADDR,
+			MODULES_END - MODULES_VADDR, KCORE_VMALLOC);
+	}
+}
+#else
+static void __init add_modules_range(void)
+{
+}
+#endif
+
+static int __init proc_kcore_init(void)
+{
+	proc_root_kcore = proc_create("kcore", S_IRUSR, NULL,
+				      &proc_kcore_operations);
+	if (!proc_root_kcore) {
+		pr_err("couldn't create /proc/kcore\n");
+		return 0; /* Always returns 0. */
+	}
+	/* Store text area if it's special */
+	proc_kcore_text_init();
+	/* Store vmalloc area */
+	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
+		VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
+	add_modules_range();
+	/* Store direct-map area from physical memory map */
+	kcore_update_ram();
+	register_hotmemory_notifier(&kcore_callback_nb);
+
+	return 0;
+}
+fs_initcall(proc_kcore_init);