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-rw-r--r--linux-user/elfload.c789
1 files changed, 257 insertions, 532 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index b8eef893d0..0c299a7c15 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -460,6 +460,7 @@ enum {
 static bool init_guest_commpage(void)
 {
     ARMCPU *cpu = ARM_CPU(thread_cpu);
+    int host_page_size = qemu_real_host_page_size();
     abi_ptr commpage;
     void *want;
     void *addr;
@@ -472,10 +473,12 @@ static bool init_guest_commpage(void)
         return true;
     }
 
-    commpage = HI_COMMPAGE & -qemu_host_page_size;
+    commpage = HI_COMMPAGE & -host_page_size;
     want = g2h_untagged(commpage);
-    addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
-                MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
+    addr = mmap(want, host_page_size, PROT_READ | PROT_WRITE,
+                MAP_ANONYMOUS | MAP_PRIVATE |
+                (commpage < reserved_va ? MAP_FIXED : MAP_FIXED_NOREPLACE),
+                -1, 0);
 
     if (addr == MAP_FAILED) {
         perror("Allocating guest commpage");
@@ -488,12 +491,12 @@ static bool init_guest_commpage(void)
     /* Set kernel helper versions; rest of page is 0.  */
     __put_user(5, (uint32_t *)g2h_untagged(0xffff0ffcu));
 
-    if (mprotect(addr, qemu_host_page_size, PROT_READ)) {
+    if (mprotect(addr, host_page_size, PROT_READ)) {
         perror("Protecting guest commpage");
         exit(EXIT_FAILURE);
     }
 
-    page_set_flags(commpage, commpage | ~qemu_host_page_mask,
+    page_set_flags(commpage, commpage | (host_page_size - 1),
                    PAGE_READ | PAGE_EXEC | PAGE_VALID);
     return true;
 }
@@ -1532,10 +1535,14 @@ static bool init_guest_commpage(void)
                  0x3a, 0x68, 0x3b, 0x00,  /* trap 0 */
     };
 
-    void *want = g2h_untagged(LO_COMMPAGE & -qemu_host_page_size);
-    void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
-                      MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
+    int host_page_size = qemu_real_host_page_size();
+    void *want, *addr;
 
+    want = g2h_untagged(LO_COMMPAGE & -host_page_size);
+    addr = mmap(want, host_page_size, PROT_READ | PROT_WRITE,
+                MAP_ANONYMOUS | MAP_PRIVATE |
+                (reserved_va ? MAP_FIXED : MAP_FIXED_NOREPLACE),
+                -1, 0);
     if (addr == MAP_FAILED) {
         perror("Allocating guest commpage");
         exit(EXIT_FAILURE);
@@ -1544,9 +1551,9 @@ static bool init_guest_commpage(void)
         return false;
     }
 
-    memcpy(addr, kuser_page, sizeof(kuser_page));
+    memcpy(g2h_untagged(LO_COMMPAGE), kuser_page, sizeof(kuser_page));
 
-    if (mprotect(addr, qemu_host_page_size, PROT_READ)) {
+    if (mprotect(addr, host_page_size, PROT_READ)) {
         perror("Protecting guest commpage");
         exit(EXIT_FAILURE);
     }
@@ -1970,16 +1977,20 @@ static inline void init_thread(struct target_pt_regs *regs,
 
 static bool init_guest_commpage(void)
 {
-    void *want = g2h_untagged(LO_COMMPAGE);
-    void *addr = mmap(want, qemu_host_page_size, PROT_NONE,
-                      MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
+    /* If reserved_va, then we have already mapped 0 page on the host. */
+    if (!reserved_va) {
+        void *want, *addr;
 
-    if (addr == MAP_FAILED) {
-        perror("Allocating guest commpage");
-        exit(EXIT_FAILURE);
-    }
-    if (addr != want) {
-        return false;
+        want = g2h_untagged(LO_COMMPAGE);
+        addr = mmap(want, TARGET_PAGE_SIZE, PROT_NONE,
+                    MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED_NOREPLACE, -1, 0);
+        if (addr == MAP_FAILED) {
+            perror("Allocating guest commpage");
+            exit(EXIT_FAILURE);
+        }
+        if (addr != want) {
+            return false;
+        }
     }
 
     /*
@@ -2679,13 +2690,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
     NEW_AUX_ENT(AT_PHDR, (abi_ulong)(info->load_addr + exec->e_phoff));
     NEW_AUX_ENT(AT_PHENT, (abi_ulong)(sizeof (struct elf_phdr)));
     NEW_AUX_ENT(AT_PHNUM, (abi_ulong)(exec->e_phnum));
-    if ((info->alignment & ~qemu_host_page_mask) != 0) {
-        /* Target doesn't support host page size alignment */
-        NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE));
-    } else {
-        NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(MAX(TARGET_PAGE_SIZE,
-                                               qemu_host_page_size)));
-    }
+    NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE));
     NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_info ? interp_info->load_addr : 0));
     NEW_AUX_ENT(AT_FLAGS, (abi_ulong)0);
     NEW_AUX_ENT(AT_ENTRY, info->entry);
@@ -2893,7 +2898,7 @@ static bool pgb_addr_set(PGBAddrs *ga, abi_ulong guest_loaddr,
 
     /* Add any HI_COMMPAGE not covered by reserved_va. */
     if (reserved_va < HI_COMMPAGE) {
-        ga->bounds[n][0] = HI_COMMPAGE & qemu_host_page_mask;
+        ga->bounds[n][0] = HI_COMMPAGE & qemu_real_host_page_mask();
         ga->bounds[n][1] = HI_COMMPAGE + TARGET_PAGE_SIZE - 1;
         n++;
     }
@@ -3017,8 +3022,6 @@ static void pgb_dynamic(const char *image_name, uintptr_t guest_loaddr,
     uintptr_t brk, ret;
     PGBAddrs ga;
 
-    assert(QEMU_IS_ALIGNED(guest_loaddr, align));
-
     /* Try the identity map first. */
     if (pgb_addr_set(&ga, guest_loaddr, guest_hiaddr, true)) {
         brk = (uintptr_t)sbrk(0);
@@ -3075,7 +3078,7 @@ void probe_guest_base(const char *image_name, abi_ulong guest_loaddr,
                       abi_ulong guest_hiaddr)
 {
     /* In order to use host shmat, we must be able to honor SHMLBA.  */
-    uintptr_t align = MAX(SHMLBA, qemu_host_page_size);
+    uintptr_t align = MAX(SHMLBA, TARGET_PAGE_SIZE);
 
     /* Sanity check the guest binary. */
     if (reserved_va) {
@@ -3912,8 +3915,9 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
                and some applications "depend" upon this behavior.  Since
                we do not have the power to recompile these, we emulate
                the SVr4 behavior.  Sigh.  */
-            target_mmap(0, qemu_host_page_size, PROT_READ | PROT_EXEC,
-                        MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+            target_mmap(0, TARGET_PAGE_SIZE, PROT_READ | PROT_EXEC,
+                        MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_ANONYMOUS,
+                        -1, 0);
         }
 #ifdef TARGET_MIPS
         info->interp_fp_abi = interp_info.fp_abi;
@@ -3963,6 +3967,8 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
 }
 
 #ifdef USE_ELF_CORE_DUMP
+#include "exec/translate-all.h"
+
 /*
  * Definitions to generate Intel SVR4-like core files.
  * These mostly have the same names as the SVR4 types with "target_elf_"
@@ -4002,18 +4008,6 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
  * Example for ARM target is provided in this file.
  */
 
-/* An ELF note in memory */
-struct memelfnote {
-    const char *name;
-    size_t     namesz;
-    size_t     namesz_rounded;
-    int        type;
-    size_t     datasz;
-    size_t     datasz_rounded;
-    void       *data;
-    size_t     notesz;
-};
-
 struct target_elf_siginfo {
     abi_int    si_signo; /* signal number */
     abi_int    si_code;  /* extra code */
@@ -4053,77 +4047,6 @@ struct target_elf_prpsinfo {
     char    pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
 };
 
-/* Here is the structure in which status of each thread is captured. */
-struct elf_thread_status {
-    QTAILQ_ENTRY(elf_thread_status)  ets_link;
-    struct target_elf_prstatus prstatus;   /* NT_PRSTATUS */
-#if 0
-    elf_fpregset_t fpu;             /* NT_PRFPREG */
-    struct task_struct *thread;
-    elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
-#endif
-    struct memelfnote notes[1];
-    int num_notes;
-};
-
-struct elf_note_info {
-    struct memelfnote   *notes;
-    struct target_elf_prstatus *prstatus;  /* NT_PRSTATUS */
-    struct target_elf_prpsinfo *psinfo;    /* NT_PRPSINFO */
-
-    QTAILQ_HEAD(, elf_thread_status) thread_list;
-#if 0
-    /*
-     * Current version of ELF coredump doesn't support
-     * dumping fp regs etc.
-     */
-    elf_fpregset_t *fpu;
-    elf_fpxregset_t *xfpu;
-    int thread_status_size;
-#endif
-    int notes_size;
-    int numnote;
-};
-
-struct vm_area_struct {
-    target_ulong   vma_start;  /* start vaddr of memory region */
-    target_ulong   vma_end;    /* end vaddr of memory region */
-    abi_ulong      vma_flags;  /* protection etc. flags for the region */
-    QTAILQ_ENTRY(vm_area_struct) vma_link;
-};
-
-struct mm_struct {
-    QTAILQ_HEAD(, vm_area_struct) mm_mmap;
-    int mm_count;           /* number of mappings */
-};
-
-static struct mm_struct *vma_init(void);
-static void vma_delete(struct mm_struct *);
-static int vma_add_mapping(struct mm_struct *, target_ulong,
-                           target_ulong, abi_ulong);
-static int vma_get_mapping_count(const struct mm_struct *);
-static struct vm_area_struct *vma_first(const struct mm_struct *);
-static struct vm_area_struct *vma_next(struct vm_area_struct *);
-static abi_ulong vma_dump_size(const struct vm_area_struct *);
-static int vma_walker(void *priv, target_ulong start, target_ulong end,
-                      unsigned long flags);
-
-static void fill_elf_header(struct elfhdr *, int, uint16_t, uint32_t);
-static void fill_note(struct memelfnote *, const char *, int,
-                      unsigned int, void *);
-static void fill_prstatus(struct target_elf_prstatus *, const TaskState *, int);
-static int fill_psinfo(struct target_elf_prpsinfo *, const TaskState *);
-static void fill_auxv_note(struct memelfnote *, const TaskState *);
-static void fill_elf_note_phdr(struct elf_phdr *, int, off_t);
-static size_t note_size(const struct memelfnote *);
-static void free_note_info(struct elf_note_info *);
-static int fill_note_info(struct elf_note_info *, long, const CPUArchState *);
-static void fill_thread_info(struct elf_note_info *, const CPUArchState *);
-
-static int dump_write(int, const void *, size_t);
-static int write_note(struct memelfnote *, int);
-static int write_note_info(struct elf_note_info *, int);
-
 #ifdef BSWAP_NEEDED
 static void bswap_prstatus(struct target_elf_prstatus *prstatus)
 {
@@ -4166,145 +4089,66 @@ static inline void bswap_note(struct elf_note *en) { }
 #endif /* BSWAP_NEEDED */
 
 /*
- * Minimal support for linux memory regions.  These are needed
- * when we are finding out what memory exactly belongs to
- * emulated process.  No locks needed here, as long as
- * thread that received the signal is stopped.
- */
-
-static struct mm_struct *vma_init(void)
-{
-    struct mm_struct *mm;
-
-    if ((mm = g_malloc(sizeof (*mm))) == NULL)
-        return (NULL);
-
-    mm->mm_count = 0;
-    QTAILQ_INIT(&mm->mm_mmap);
-
-    return (mm);
-}
-
-static void vma_delete(struct mm_struct *mm)
-{
-    struct vm_area_struct *vma;
-
-    while ((vma = vma_first(mm)) != NULL) {
-        QTAILQ_REMOVE(&mm->mm_mmap, vma, vma_link);
-        g_free(vma);
-    }
-    g_free(mm);
-}
-
-static int vma_add_mapping(struct mm_struct *mm, target_ulong start,
-                           target_ulong end, abi_ulong flags)
-{
-    struct vm_area_struct *vma;
-
-    if ((vma = g_malloc0(sizeof (*vma))) == NULL)
-        return (-1);
-
-    vma->vma_start = start;
-    vma->vma_end = end;
-    vma->vma_flags = flags;
-
-    QTAILQ_INSERT_TAIL(&mm->mm_mmap, vma, vma_link);
-    mm->mm_count++;
-
-    return (0);
-}
-
-static struct vm_area_struct *vma_first(const struct mm_struct *mm)
-{
-    return (QTAILQ_FIRST(&mm->mm_mmap));
-}
-
-static struct vm_area_struct *vma_next(struct vm_area_struct *vma)
-{
-    return (QTAILQ_NEXT(vma, vma_link));
-}
-
-static int vma_get_mapping_count(const struct mm_struct *mm)
-{
-    return (mm->mm_count);
-}
-
-/*
  * Calculate file (dump) size of given memory region.
  */
-static abi_ulong vma_dump_size(const struct vm_area_struct *vma)
+static size_t vma_dump_size(target_ulong start, target_ulong end,
+                            unsigned long flags)
 {
-    /* if we cannot even read the first page, skip it */
-    if (!access_ok_untagged(VERIFY_READ, vma->vma_start, TARGET_PAGE_SIZE))
-        return (0);
+    /* The area must be readable. */
+    if (!(flags & PAGE_READ)) {
+        return 0;
+    }
 
     /*
      * Usually we don't dump executable pages as they contain
      * non-writable code that debugger can read directly from
-     * target library etc.  However, thread stacks are marked
-     * also executable so we read in first page of given region
-     * and check whether it contains elf header.  If there is
-     * no elf header, we dump it.
+     * target library etc. If there is no elf header, we dump it.
      */
-    if (vma->vma_flags & PROT_EXEC) {
-        char page[TARGET_PAGE_SIZE];
-
-        if (copy_from_user(page, vma->vma_start, sizeof (page))) {
-            return 0;
-        }
-        if ((page[EI_MAG0] == ELFMAG0) &&
-            (page[EI_MAG1] == ELFMAG1) &&
-            (page[EI_MAG2] == ELFMAG2) &&
-            (page[EI_MAG3] == ELFMAG3)) {
-            /*
-             * Mappings are possibly from ELF binary.  Don't dump
-             * them.
-             */
-            return (0);
-        }
+    if (!(flags & PAGE_WRITE_ORG) &&
+        (flags & PAGE_EXEC) &&
+        memcmp(g2h_untagged(start), ELFMAG, SELFMAG) == 0) {
+        return 0;
     }
 
-    return (vma->vma_end - vma->vma_start);
+    return end - start;
 }
 
-static int vma_walker(void *priv, target_ulong start, target_ulong end,
-                      unsigned long flags)
+static size_t size_note(const char *name, size_t datasz)
 {
-    struct mm_struct *mm = (struct mm_struct *)priv;
+    size_t namesz = strlen(name) + 1;
 
-    vma_add_mapping(mm, start, end, flags);
-    return (0);
+    namesz = ROUND_UP(namesz, 4);
+    datasz = ROUND_UP(datasz, 4);
+
+    return sizeof(struct elf_note) + namesz + datasz;
 }
 
-static void fill_note(struct memelfnote *note, const char *name, int type,
-                      unsigned int sz, void *data)
+static void *fill_note(void **pptr, int type, const char *name, size_t datasz)
 {
-    unsigned int namesz;
+    void *ptr = *pptr;
+    struct elf_note *n = ptr;
+    size_t namesz = strlen(name) + 1;
 
-    namesz = strlen(name) + 1;
-    note->name = name;
-    note->namesz = namesz;
-    note->namesz_rounded = roundup(namesz, sizeof (int32_t));
-    note->type = type;
-    note->datasz = sz;
-    note->datasz_rounded = roundup(sz, sizeof (int32_t));
+    n->n_namesz = namesz;
+    n->n_descsz = datasz;
+    n->n_type = type;
+    bswap_note(n);
 
-    note->data = data;
+    ptr += sizeof(*n);
+    memcpy(ptr, name, namesz);
 
-    /*
-     * We calculate rounded up note size here as specified by
-     * ELF document.
-     */
-    note->notesz = sizeof (struct elf_note) +
-        note->namesz_rounded + note->datasz_rounded;
+    namesz = ROUND_UP(namesz, 4);
+    datasz = ROUND_UP(datasz, 4);
+
+    *pptr = ptr + namesz + datasz;
+    return ptr + namesz;
 }
 
 static void fill_elf_header(struct elfhdr *elf, int segs, uint16_t machine,
                             uint32_t flags)
 {
-    (void) memset(elf, 0, sizeof(*elf));
+    memcpy(elf->e_ident, ELFMAG, SELFMAG);
 
-    (void) 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;
@@ -4322,95 +4166,79 @@ static void fill_elf_header(struct elfhdr *elf, int segs, uint16_t machine,
     bswap_ehdr(elf);
 }
 
-static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, off_t offset)
+static void fill_elf_note_phdr(struct elf_phdr *phdr, size_t sz, off_t offset)
 {
     phdr->p_type = PT_NOTE;
     phdr->p_offset = offset;
-    phdr->p_vaddr = 0;
-    phdr->p_paddr = 0;
     phdr->p_filesz = sz;
-    phdr->p_memsz = 0;
-    phdr->p_flags = 0;
-    phdr->p_align = 0;
 
     bswap_phdr(phdr, 1);
 }
 
-static size_t note_size(const struct memelfnote *note)
+static void fill_prstatus_note(void *data, const TaskState *ts,
+                               CPUState *cpu, int signr)
 {
-    return (note->notesz);
-}
+    /*
+     * Because note memory is only aligned to 4, and target_elf_prstatus
+     * may well have higher alignment requirements, fill locally and
+     * memcpy to the destination afterward.
+     */
+    struct target_elf_prstatus prstatus = {
+        .pr_info.si_signo = signr,
+        .pr_cursig = signr,
+        .pr_pid = ts->ts_tid,
+        .pr_ppid = getppid(),
+        .pr_pgrp = getpgrp(),
+        .pr_sid = getsid(0),
+    };
 
-static void fill_prstatus(struct target_elf_prstatus *prstatus,
-                          const TaskState *ts, int signr)
-{
-    (void) memset(prstatus, 0, sizeof (*prstatus));
-    prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
-    prstatus->pr_pid = ts->ts_tid;
-    prstatus->pr_ppid = getppid();
-    prstatus->pr_pgrp = getpgrp();
-    prstatus->pr_sid = getsid(0);
-
-    bswap_prstatus(prstatus);
+    elf_core_copy_regs(&prstatus.pr_reg, cpu_env(cpu));
+    bswap_prstatus(&prstatus);
+    memcpy(data, &prstatus, sizeof(prstatus));
 }
 
-static int fill_psinfo(struct target_elf_prpsinfo *psinfo, const TaskState *ts)
+static void fill_prpsinfo_note(void *data, const TaskState *ts)
 {
+    /*
+     * Because note memory is only aligned to 4, and target_elf_prpsinfo
+     * may well have higher alignment requirements, fill locally and
+     * memcpy to the destination afterward.
+     */
+    struct target_elf_prpsinfo psinfo;
     char *base_filename;
-    unsigned int i, len;
-
-    (void) memset(psinfo, 0, sizeof (*psinfo));
+    size_t len;
 
     len = ts->info->env_strings - ts->info->arg_strings;
-    if (len >= ELF_PRARGSZ)
-        len = ELF_PRARGSZ - 1;
-    if (copy_from_user(&psinfo->pr_psargs, ts->info->arg_strings, len)) {
-        return -EFAULT;
-    }
-    for (i = 0; i < len; i++)
-        if (psinfo->pr_psargs[i] == 0)
-            psinfo->pr_psargs[i] = ' ';
-    psinfo->pr_psargs[len] = 0;
-
-    psinfo->pr_pid = getpid();
-    psinfo->pr_ppid = getppid();
-    psinfo->pr_pgrp = getpgrp();
-    psinfo->pr_sid = getsid(0);
-    psinfo->pr_uid = getuid();
-    psinfo->pr_gid = getgid();
+    len = MIN(len, ELF_PRARGSZ);
+    memcpy(&psinfo.pr_psargs, g2h_untagged(ts->info->arg_strings), len);
+    for (size_t i = 0; i < len; i++) {
+        if (psinfo.pr_psargs[i] == 0) {
+            psinfo.pr_psargs[i] = ' ';
+        }
+    }
+
+    psinfo.pr_pid = getpid();
+    psinfo.pr_ppid = getppid();
+    psinfo.pr_pgrp = getpgrp();
+    psinfo.pr_sid = getsid(0);
+    psinfo.pr_uid = getuid();
+    psinfo.pr_gid = getgid();
 
     base_filename = g_path_get_basename(ts->bprm->filename);
     /*
      * Using strncpy here is fine: at max-length,
      * this field is not NUL-terminated.
      */
-    (void) strncpy(psinfo->pr_fname, base_filename,
-                   sizeof(psinfo->pr_fname));
-
+    strncpy(psinfo.pr_fname, base_filename, sizeof(psinfo.pr_fname));
     g_free(base_filename);
-    bswap_psinfo(psinfo);
-    return (0);
+
+    bswap_psinfo(&psinfo);
+    memcpy(data, &psinfo, sizeof(psinfo));
 }
 
-static void fill_auxv_note(struct memelfnote *note, const TaskState *ts)
+static void fill_auxv_note(void *data, const TaskState *ts)
 {
-    elf_addr_t auxv = (elf_addr_t)ts->info->saved_auxv;
-    elf_addr_t orig_auxv = auxv;
-    void *ptr;
-    int len = ts->info->auxv_len;
-
-    /*
-     * Auxiliary vector is stored in target process stack.  It contains
-     * {type, value} pairs that we need to dump into note.  This is not
-     * strictly necessary but we do it here for sake of completeness.
-     */
-
-    /* read in whole auxv vector and copy it to memelfnote */
-    ptr = lock_user(VERIFY_READ, orig_auxv, len, 0);
-    if (ptr != NULL) {
-        fill_note(note, "CORE", NT_AUXV, len, ptr);
-        unlock_user(ptr, auxv, len);
-    }
+    memcpy(data, g2h_untagged(ts->info->saved_auxv), ts->info->auxv_len);
 }
 
 /*
@@ -4434,27 +4262,9 @@ static int dump_write(int fd, const void *ptr, size_t size)
 {
     const char *bufp = (const char *)ptr;
     ssize_t bytes_written, bytes_left;
-    struct rlimit dumpsize;
-    off_t pos;
 
     bytes_written = 0;
-    getrlimit(RLIMIT_CORE, &dumpsize);
-    if ((pos = lseek(fd, 0, SEEK_CUR))==-1) {
-        if (errno == ESPIPE) { /* not a seekable stream */
-            bytes_left = size;
-        } else {
-            return pos;
-        }
-    } else {
-        if (dumpsize.rlim_cur <= pos) {
-            return -1;
-        } else if (dumpsize.rlim_cur == RLIM_INFINITY) {
-            bytes_left = size;
-        } else {
-            size_t limit_left=dumpsize.rlim_cur - pos;
-            bytes_left = limit_left >= size ? size : limit_left ;
-        }
-    }
+    bytes_left = size;
 
     /*
      * In normal conditions, single write(2) should do but
@@ -4476,135 +4286,76 @@ static int dump_write(int fd, const void *ptr, size_t size)
     return (0);
 }
 
-static int write_note(struct memelfnote *men, int fd)
+static int wmr_page_unprotect_regions(void *opaque, target_ulong start,
+                                      target_ulong end, unsigned long flags)
 {
-    struct elf_note en;
-
-    en.n_namesz = men->namesz;
-    en.n_type = men->type;
-    en.n_descsz = men->datasz;
+    if ((flags & (PAGE_WRITE | PAGE_WRITE_ORG)) == PAGE_WRITE_ORG) {
+        size_t step = MAX(TARGET_PAGE_SIZE, qemu_real_host_page_size());
 
-    bswap_note(&en);
-
-    if (dump_write(fd, &en, sizeof(en)) != 0)
-        return (-1);
-    if (dump_write(fd, men->name, men->namesz_rounded) != 0)
-        return (-1);
-    if (dump_write(fd, men->data, men->datasz_rounded) != 0)
-        return (-1);
-
-    return (0);
-}
-
-static void fill_thread_info(struct elf_note_info *info, const CPUArchState *env)
-{
-    CPUState *cpu = env_cpu((CPUArchState *)env);
-    TaskState *ts = (TaskState *)cpu->opaque;
-    struct elf_thread_status *ets;
-
-    ets = g_malloc0(sizeof (*ets));
-    ets->num_notes = 1; /* only prstatus is dumped */
-    fill_prstatus(&ets->prstatus, ts, 0);
-    elf_core_copy_regs(&ets->prstatus.pr_reg, env);
-    fill_note(&ets->notes[0], "CORE", NT_PRSTATUS, sizeof (ets->prstatus),
-              &ets->prstatus);
-
-    QTAILQ_INSERT_TAIL(&info->thread_list, ets, ets_link);
-
-    info->notes_size += note_size(&ets->notes[0]);
+        while (1) {
+            page_unprotect(start, 0);
+            if (end - start <= step) {
+                break;
+            }
+            start += step;
+        }
+    }
+    return 0;
 }
 
-static void init_note_info(struct elf_note_info *info)
-{
-    /* Initialize the elf_note_info structure so that it is at
-     * least safe to call free_note_info() on it. Must be
-     * called before calling fill_note_info().
-     */
-    memset(info, 0, sizeof (*info));
-    QTAILQ_INIT(&info->thread_list);
-}
+typedef struct {
+    unsigned count;
+    size_t size;
+} CountAndSizeRegions;
 
-static int fill_note_info(struct elf_note_info *info,
-                          long signr, const CPUArchState *env)
+static int wmr_count_and_size_regions(void *opaque, target_ulong start,
+                                      target_ulong end, unsigned long flags)
 {
-#define NUMNOTES 3
-    CPUState *cpu = env_cpu((CPUArchState *)env);
-    TaskState *ts = (TaskState *)cpu->opaque;
-    int i;
-
-    info->notes = g_new0(struct memelfnote, NUMNOTES);
-    if (info->notes == NULL)
-        return (-ENOMEM);
-    info->prstatus = g_malloc0(sizeof (*info->prstatus));
-    if (info->prstatus == NULL)
-        return (-ENOMEM);
-    info->psinfo = g_malloc0(sizeof (*info->psinfo));
-    if (info->prstatus == NULL)
-        return (-ENOMEM);
-
-    /*
-     * First fill in status (and registers) of current thread
-     * including process info & aux vector.
-     */
-    fill_prstatus(info->prstatus, ts, signr);
-    elf_core_copy_regs(&info->prstatus->pr_reg, env);
-    fill_note(&info->notes[0], "CORE", NT_PRSTATUS,
-              sizeof (*info->prstatus), info->prstatus);
-    fill_psinfo(info->psinfo, ts);
-    fill_note(&info->notes[1], "CORE", NT_PRPSINFO,
-              sizeof (*info->psinfo), info->psinfo);
-    fill_auxv_note(&info->notes[2], ts);
-    info->numnote = 3;
-
-    info->notes_size = 0;
-    for (i = 0; i < info->numnote; i++)
-        info->notes_size += note_size(&info->notes[i]);
-
-    /* read and fill status of all threads */
-    WITH_QEMU_LOCK_GUARD(&qemu_cpu_list_lock) {
-        CPU_FOREACH(cpu) {
-            if (cpu == thread_cpu) {
-                continue;
-            }
-            fill_thread_info(info, cpu_env(cpu));
-        }
-    }
+    CountAndSizeRegions *css = opaque;
 
-    return (0);
+    css->count++;
+    css->size += vma_dump_size(start, end, flags);
+    return 0;
 }
 
-static void free_note_info(struct elf_note_info *info)
+typedef struct {
+    struct elf_phdr *phdr;
+    off_t offset;
+} FillRegionPhdr;
+
+static int wmr_fill_region_phdr(void *opaque, target_ulong start,
+                                target_ulong end, unsigned long flags)
 {
-    struct elf_thread_status *ets;
+    FillRegionPhdr *d = opaque;
+    struct elf_phdr *phdr = d->phdr;
 
-    while (!QTAILQ_EMPTY(&info->thread_list)) {
-        ets = QTAILQ_FIRST(&info->thread_list);
-        QTAILQ_REMOVE(&info->thread_list, ets, ets_link);
-        g_free(ets);
-    }
+    phdr->p_type = PT_LOAD;
+    phdr->p_vaddr = start;
+    phdr->p_paddr = 0;
+    phdr->p_filesz = vma_dump_size(start, end, flags);
+    phdr->p_offset = d->offset;
+    d->offset += phdr->p_filesz;
+    phdr->p_memsz = end - start;
+    phdr->p_flags = (flags & PAGE_READ ? PF_R : 0)
+                  | (flags & PAGE_WRITE_ORG ? PF_W : 0)
+                  | (flags & PAGE_EXEC ? PF_X : 0);
+    phdr->p_align = ELF_EXEC_PAGESIZE;
 
-    g_free(info->prstatus);
-    g_free(info->psinfo);
-    g_free(info->notes);
+    bswap_phdr(phdr, 1);
+    d->phdr = phdr + 1;
+    return 0;
 }
 
-static int write_note_info(struct elf_note_info *info, int fd)
+static int wmr_write_region(void *opaque, target_ulong start,
+                            target_ulong end, unsigned long flags)
 {
-    struct elf_thread_status *ets;
-    int i, error = 0;
+    int fd = *(int *)opaque;
+    size_t size = vma_dump_size(start, end, flags);
 
-    /* write prstatus, psinfo and auxv for current thread */
-    for (i = 0; i < info->numnote; i++)
-        if ((error = write_note(&info->notes[i], fd)) != 0)
-            return (error);
-
-    /* write prstatus for each thread */
-    QTAILQ_FOREACH(ets, &info->thread_list, ets_link) {
-        if ((error = write_note(&ets->notes[0], fd)) != 0)
-            return (error);
+    if (!size) {
+        return 0;
     }
-
-    return (0);
+    return dump_write(fd, g2h_untagged(start), size);
 }
 
 /*
@@ -4654,151 +4405,125 @@ static int elf_core_dump(int signr, const CPUArchState *env)
 {
     const CPUState *cpu = env_cpu((CPUArchState *)env);
     const TaskState *ts = (const TaskState *)cpu->opaque;
-    struct vm_area_struct *vma = NULL;
-    g_autofree char *corefile = NULL;
-    struct elf_note_info info;
-    struct elfhdr elf;
-    struct elf_phdr phdr;
     struct rlimit dumpsize;
-    struct mm_struct *mm = NULL;
-    off_t offset = 0, data_offset = 0;
-    int segs = 0;
+    CountAndSizeRegions css;
+    off_t offset, note_offset, data_offset;
+    size_t note_size;
+    int cpus, ret;
     int fd = -1;
-
-    init_note_info(&info);
-
-    errno = 0;
+    CPUState *cpu_iter;
 
     if (prctl(PR_GET_DUMPABLE) == 0) {
         return 0;
     }
 
-    if (getrlimit(RLIMIT_CORE, &dumpsize) == 0 && dumpsize.rlim_cur == 0) {
+    if (getrlimit(RLIMIT_CORE, &dumpsize) < 0 || dumpsize.rlim_cur == 0) {
         return 0;
     }
 
-    corefile = core_dump_filename(ts);
+    cpu_list_lock();
+    mmap_lock();
 
-    if ((fd = open(corefile, O_WRONLY | O_CREAT,
-                   S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
-        return (-errno);
+    /* By unprotecting, we merge vmas that might be split. */
+    walk_memory_regions(NULL, wmr_page_unprotect_regions);
 
     /*
      * Walk through target process memory mappings and
-     * set up structure containing this information.  After
-     * this point vma_xxx functions can be used.
+     * set up structure containing this information.
      */
-    if ((mm = vma_init()) == NULL)
-        goto out;
+    memset(&css, 0, sizeof(css));
+    walk_memory_regions(&css, wmr_count_and_size_regions);
 
-    walk_memory_regions(mm, vma_walker);
-    segs = vma_get_mapping_count(mm);
-
-    /*
-     * Construct valid coredump ELF header.  We also
-     * add one more segment for notes.
-     */
-    fill_elf_header(&elf, segs + 1, ELF_MACHINE, 0);
-    if (dump_write(fd, &elf, sizeof (elf)) != 0)
-        goto out;
+    cpus = 0;
+    CPU_FOREACH(cpu_iter) {
+        cpus++;
+    }
 
-    /* fill in the in-memory version of notes */
-    if (fill_note_info(&info, signr, env) < 0)
-        goto out;
+    offset = sizeof(struct elfhdr);
+    offset += (css.count + 1) * sizeof(struct elf_phdr);
+    note_offset = offset;
 
-    offset += sizeof (elf);                             /* elf header */
-    offset += (segs + 1) * sizeof (struct elf_phdr);    /* program headers */
+    offset += size_note("CORE", ts->info->auxv_len);
+    offset += size_note("CORE", sizeof(struct target_elf_prpsinfo));
+    offset += size_note("CORE", sizeof(struct target_elf_prstatus)) * cpus;
+    note_size = offset - note_offset;
+    data_offset = ROUND_UP(offset, ELF_EXEC_PAGESIZE);
 
-    /* write out notes program header */
-    fill_elf_note_phdr(&phdr, info.notes_size, offset);
+    /* Do not dump if the corefile size exceeds the limit. */
+    if (dumpsize.rlim_cur != RLIM_INFINITY
+        && dumpsize.rlim_cur < data_offset + css.size) {
+        errno = 0;
+        goto out;
+    }
 
-    offset += info.notes_size;
-    if (dump_write(fd, &phdr, sizeof (phdr)) != 0)
+    {
+        g_autofree char *corefile = core_dump_filename(ts);
+        fd = open(corefile, O_WRONLY | O_CREAT | O_TRUNC,
+                  S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    }
+    if (fd < 0) {
         goto out;
+    }
 
     /*
-     * ELF specification wants data to start at page boundary so
-     * we align it here.
+     * There is a fair amount of alignment padding within the notes
+     * as well as preceeding the process memory.  Allocate a zeroed
+     * block to hold it all.  Write all of the headers directly into
+     * this buffer and then write it out as a block.
      */
-    data_offset = offset = roundup(offset, ELF_EXEC_PAGESIZE);
+    {
+        g_autofree void *header = g_malloc0(data_offset);
+        FillRegionPhdr frp;
+        void *hptr, *dptr;
+
+        /* Create elf file header. */
+        hptr = header;
+        fill_elf_header(hptr, css.count + 1, ELF_MACHINE, 0);
+        hptr += sizeof(struct elfhdr);
+
+        /* Create elf program headers. */
+        fill_elf_note_phdr(hptr, note_size, note_offset);
+        hptr += sizeof(struct elf_phdr);
+
+        frp.phdr = hptr;
+        frp.offset = data_offset;
+        walk_memory_regions(&frp, wmr_fill_region_phdr);
+        hptr = frp.phdr;
+
+        /* Create the notes. */
+        dptr = fill_note(&hptr, NT_AUXV, "CORE", ts->info->auxv_len);
+        fill_auxv_note(dptr, ts);
+
+        dptr = fill_note(&hptr, NT_PRPSINFO, "CORE",
+                         sizeof(struct target_elf_prpsinfo));
+        fill_prpsinfo_note(dptr, ts);
+
+        CPU_FOREACH(cpu_iter) {
+            dptr = fill_note(&hptr, NT_PRSTATUS, "CORE",
+                             sizeof(struct target_elf_prstatus));
+            fill_prstatus_note(dptr, ts, cpu_iter,
+                               cpu_iter == cpu ? signr : 0);
+        }
 
-    /*
-     * Write program headers for memory regions mapped in
-     * the target process.
-     */
-    for (vma = vma_first(mm); vma != NULL; vma = vma_next(vma)) {
-        (void) memset(&phdr, 0, sizeof (phdr));
-
-        phdr.p_type = PT_LOAD;
-        phdr.p_offset = offset;
-        phdr.p_vaddr = vma->vma_start;
-        phdr.p_paddr = 0;
-        phdr.p_filesz = vma_dump_size(vma);
-        offset += phdr.p_filesz;
-        phdr.p_memsz = vma->vma_end - vma->vma_start;
-        phdr.p_flags = vma->vma_flags & PROT_READ ? PF_R : 0;
-        if (vma->vma_flags & PROT_WRITE)
-            phdr.p_flags |= PF_W;
-        if (vma->vma_flags & PROT_EXEC)
-            phdr.p_flags |= PF_X;
-        phdr.p_align = ELF_EXEC_PAGESIZE;
-
-        bswap_phdr(&phdr, 1);
-        if (dump_write(fd, &phdr, sizeof(phdr)) != 0) {
+        if (dump_write(fd, header, data_offset) < 0) {
             goto out;
         }
     }
 
     /*
-     * Next we write notes just after program headers.  No
-     * alignment needed here.
+     * Finally write process memory into the corefile as well.
      */
-    if (write_note_info(&info, fd) < 0)
+    if (walk_memory_regions(&fd, wmr_write_region) < 0) {
         goto out;
-
-    /* align data to page boundary */
-    if (lseek(fd, data_offset, SEEK_SET) != data_offset)
-        goto out;
-
-    /*
-     * Finally we can dump process memory into corefile as well.
-     */
-    for (vma = vma_first(mm); vma != NULL; vma = vma_next(vma)) {
-        abi_ulong addr;
-        abi_ulong end;
-
-        end = vma->vma_start + vma_dump_size(vma);
-
-        for (addr = vma->vma_start; addr < end;
-             addr += TARGET_PAGE_SIZE) {
-            char page[TARGET_PAGE_SIZE];
-            int error;
-
-            /*
-             *  Read in page from target process memory and
-             *  write it to coredump file.
-             */
-            error = copy_from_user(page, addr, sizeof (page));
-            if (error != 0) {
-                (void) fprintf(stderr, "unable to dump " TARGET_ABI_FMT_lx "\n",
-                               addr);
-                errno = -error;
-                goto out;
-            }
-            if (dump_write(fd, page, TARGET_PAGE_SIZE) < 0)
-                goto out;
-        }
     }
+    errno = 0;
 
  out:
-    free_note_info(&info);
-    if (mm != NULL)
-        vma_delete(mm);
-    (void) close(fd);
-
-    if (errno != 0)
-        return (-errno);
-    return (0);
+    ret = -errno;
+    mmap_unlock();
+    cpu_list_unlock();
+    close(fd);
+    return ret;
 }
 #endif /* USE_ELF_CORE_DUMP */