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-rw-r--r--fs/proc/kcore.c404
1 files changed, 404 insertions, 0 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
new file mode 100644
index 00000000000..1c7da988fcc
--- /dev/null
+++ b/fs/proc/kcore.c
@@ -0,0 +1,404 @@
+/*
+ * 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/config.h>
+#include <linux/mm.h>
+#include <linux/proc_fs.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/vmalloc.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+
+static int open_kcore(struct inode * inode, struct file * filp)
+{
+ return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
+}
+
+static ssize_t read_kcore(struct file *, char __user *, size_t, loff_t *);
+
+struct file_operations proc_kcore_operations = {
+ .read = read_kcore,
+ .open = open_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
+
+#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
+
+/* An ELF note in memory */
+struct memelfnote
+{
+ const char *name;
+ int type;
+ unsigned int datasz;
+ void *data;
+};
+
+static struct kcore_list *kclist;
+static DEFINE_RWLOCK(kclist_lock);
+
+void
+kclist_add(struct kcore_list *new, void *addr, size_t size)
+{
+ new->addr = (unsigned long)addr;
+ new->size = size;
+
+ write_lock(&kclist_lock);
+ new->next = kclist;
+ kclist = new;
+ 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;
+
+ for (m=kclist; m; m=m->next) {
+ 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) + 4) +
+ sizeof(struct elf_prstatus) +
+ sizeof(struct elf_prpsinfo) +
+ sizeof(struct task_struct);
+ *elf_buflen = PAGE_ALIGN(*elf_buflen);
+ return size + *elf_buflen;
+}
+
+
+/*****************************************************************************/
+/*
+ * determine size of ELF note
+ */
+static int notesize(struct memelfnote *en)
+{
+ int sz;
+
+ sz = sizeof(struct elf_note);
+ sz += roundup(strlen(en->name), 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);
+ 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;
+#if defined(CONFIG_H8300)
+ elf->e_flags = ELF_FLAGS;
+#else
+ elf->e_flags = 0;
+#endif
+ 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 */
+ for (m=kclist; m; m=m->next) {
+ 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";
+ 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";
+ 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");
+ strncpy(prpsinfo.pr_psargs, saved_command_line, ELF_PRARGSZ);
+
+ nhdr->p_filesz += notesize(&notes[1]);
+ bufp = storenote(&notes[1], bufp);
+
+ /* set up the task structure */
+ notes[2].name = "CORE";
+ 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);
+ proc_root_kcore->size = 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 = kmalloc(elf_buflen, GFP_ATOMIC);
+ if (!elf_buf) {
+ read_unlock(&kclist_lock);
+ return -ENOMEM;
+ }
+ memset(elf_buf, 0, elf_buflen);
+ 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);
+ for (m=kclist; m; m=m->next) {
+ if (start >= m->addr && start < (m->addr+m->size))
+ break;
+ }
+ read_unlock(&kclist_lock);
+
+ if (m == NULL) {
+ if (clear_user(buffer, tsz))
+ return -EFAULT;
+ } else if ((start >= VMALLOC_START) && (start < VMALLOC_END)) {
+ char * elf_buf;
+ struct vm_struct *m;
+ unsigned long curstart = start;
+ unsigned long cursize = tsz;
+
+ elf_buf = kmalloc(tsz, GFP_KERNEL);
+ if (!elf_buf)
+ return -ENOMEM;
+ memset(elf_buf, 0, tsz);
+
+ read_lock(&vmlist_lock);
+ for (m=vmlist; m && cursize; m=m->next) {
+ unsigned long vmstart;
+ unsigned long vmsize;
+ unsigned long msize = m->size - PAGE_SIZE;
+
+ if (((unsigned long)m->addr + msize) <
+ curstart)
+ continue;
+ if ((unsigned long)m->addr > (curstart +
+ cursize))
+ break;
+ vmstart = (curstart < (unsigned long)m->addr ?
+ (unsigned long)m->addr : curstart);
+ if (((unsigned long)m->addr + msize) >
+ (curstart + cursize))
+ vmsize = curstart + cursize - vmstart;
+ else
+ vmsize = (unsigned long)m->addr +
+ msize - vmstart;
+ curstart = vmstart + vmsize;
+ cursize -= vmsize;
+ /* don't dump ioremap'd stuff! (TA) */
+ if (m->flags & VM_IOREMAP)
+ continue;
+ memcpy(elf_buf + (vmstart - start),
+ (char *)vmstart, vmsize);
+ }
+ read_unlock(&vmlist_lock);
+ 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 distingush 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,
+ tsz - 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;
+}
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