linux-user: implemented ELF coredump support for ARM target

When target process is killed with signal (such signal that
should dump core) a coredump file is created.  This file is
similar than coredump generated by Linux (there are few exceptions
though).

Riku Voipio: added support for rlimit

Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Riku Voipio <riku.voipio@iki.fi>

9 files changed, 1101 insertions, 68 deletions

diff --git a/cpu-all.h b/cpu-all.h
index dc9b034cbc..8f078c415b 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -735,6 +735,8 @@ extern unsigned long qemu_host_page_mask;
 #define PAGE_RESERVED  0x0020
 
 void page_dump(FILE *f);
+int walk_memory_regions(void *,
+    int (*fn)(void *, unsigned long, unsigned long, unsigned long));
 int page_get_flags(target_ulong address);
 void page_set_flags(target_ulong start, target_ulong end, int flags);
 int page_check_range(target_ulong start, target_ulong len, int flags);
diff --git a/elf.h b/elf.h
index 182cad92de..b0420029df 100644
--- a/elf.h
+++ b/elf.h
@@ -1081,7 +1081,23 @@ typedef struct elf64_shdr {
 #define	EI_CLASS	4
 #define	EI_DATA		5
 #define	EI_VERSION	6
-#define	EI_PAD		7
+#define	EI_OSABI	7
+#define	EI_PAD		8
+
+#define ELFOSABI_NONE           0       /* UNIX System V ABI */
+#define ELFOSABI_SYSV           0       /* Alias.  */
+#define ELFOSABI_HPUX           1       /* HP-UX */
+#define ELFOSABI_NETBSD         2       /* NetBSD.  */
+#define ELFOSABI_LINUX          3       /* Linux.  */
+#define ELFOSABI_SOLARIS        6       /* Sun Solaris.  */
+#define ELFOSABI_AIX            7       /* IBM AIX.  */
+#define ELFOSABI_IRIX           8       /* SGI Irix.  */
+#define ELFOSABI_FREEBSD        9       /* FreeBSD.  */
+#define ELFOSABI_TRU64          10      /* Compaq TRU64 UNIX.  */
+#define ELFOSABI_MODESTO        11      /* Novell Modesto.  */
+#define ELFOSABI_OPENBSD        12      /* OpenBSD.  */
+#define ELFOSABI_ARM            97      /* ARM */
+#define ELFOSABI_STANDALONE     255     /* Standalone (embedded) application */
 
 #define	ELFMAG0		0x7f		/* EI_MAG */
 #define	ELFMAG1		'E'
@@ -1108,6 +1124,7 @@ typedef struct elf64_shdr {
 #define NT_PRFPREG	2
 #define NT_PRPSINFO	3
 #define NT_TASKSTRUCT	4
+#define NT_AUXV		6
 #define NT_PRXFPREG     0x46e62b7f      /* copied from gdb5.1/include/elf/common.h */
 
 
diff --git a/exec.c b/exec.c
index 52f4e89251..9e7d66ac52 100644
--- a/exec.c
+++ b/exec.c
@@ -2131,36 +2131,36 @@ int tlb_set_page_exec(CPUState *env, target_ulong vaddr,
     return 0;
 }
 
-/* dump memory mappings */
-void page_dump(FILE *f)
+/*
+ * Walks guest process memory "regions" one by one
+ * and calls callback function 'fn' for each region.
+ */
+int walk_memory_regions(void *priv,
+    int (*fn)(void *, unsigned long, unsigned long, unsigned long))
 {
     unsigned long start, end;
+    PageDesc *p = NULL;
     int i, j, prot, prot1;
-    PageDesc *p;
+    int rc = 0;
 
-    fprintf(f, "%-8s %-8s %-8s %s\n",
-            "start", "end", "size", "prot");
-    start = -1;
-    end = -1;
+    start = end = -1;
     prot = 0;
-    for(i = 0; i <= L1_SIZE; i++) {
-        if (i < L1_SIZE)
-            p = l1_map[i];
-        else
-            p = NULL;
-        for(j = 0;j < L2_SIZE; j++) {
-            if (!p)
-                prot1 = 0;
-            else
-                prot1 = p[j].flags;
+
+    for (i = 0; i <= L1_SIZE; i++) {
+        p = (i < L1_SIZE) ? l1_map[i] : NULL;
+        for (j = 0; j < L2_SIZE; j++) {
+            prot1 = (p == NULL) ? 0 : p[j].flags;
+            /*
+             * "region" is one continuous chunk of memory
+             * that has same protection flags set.
+             */
             if (prot1 != prot) {
                 end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
                 if (start != -1) {
-                    fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
-                            start, end, end - start,
-                            prot & PAGE_READ ? 'r' : '-',
-                            prot & PAGE_WRITE ? 'w' : '-',
-                            prot & PAGE_EXEC ? 'x' : '-');
+                    rc = (*fn)(priv, start, end, prot);
+                    /* callback can stop iteration by returning != 0 */
+                    if (rc != 0)
+                        return (rc);
                 }
                 if (prot1 != 0)
                     start = end;
@@ -2168,10 +2168,33 @@ void page_dump(FILE *f)
                     start = -1;
                 prot = prot1;
             }
-            if (!p)
+            if (p == NULL)
                 break;
         }
     }
+    return (rc);
+}
+
+static int dump_region(void *priv, unsigned long start,
+    unsigned long end, unsigned long prot)
+{
+    FILE *f = (FILE *)priv;
+
+    (void) fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
+        start, end, end - start,
+        ((prot & PAGE_READ) ? 'r' : '-'),
+        ((prot & PAGE_WRITE) ? 'w' : '-'),
+        ((prot & PAGE_EXEC) ? 'x' : '-'));
+
+    return (0);
+}
+
+/* dump memory mappings */
+void page_dump(FILE *f)
+{
+    (void) fprintf(f, "%-8s %-8s %-8s %s\n",
+            "start", "end", "size", "prot");
+    walk_memory_regions(f, dump_region);
 }
 
 int page_get_flags(target_ulong address)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 190ad143e0..8996c16126 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1,4 +1,6 @@
 /* This is the Linux kernel elf-loading code, ported into user space */
+#include <sys/time.h>
+#include <sys/param.h>
 
 #include <stdio.h>
 #include <sys/types.h>
@@ -6,8 +8,10 @@
 #include <errno.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
 #include "qemu.h"
 #include "disas.h"
@@ -21,6 +25,8 @@
 #undef ELF_ARCH
 #endif
 
+#define ELF_OSABI   ELFOSABI_SYSV
+
 /* from personality.h */
 
 /*
@@ -160,7 +166,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
 }
 #endif
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE	4096
 
 #endif
@@ -198,6 +203,37 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
     regs->ARM_r10 = infop->start_data;
 }
 
+typedef uint32_t elf_greg_t;
+typedef uint16_t target_uid_t;
+typedef uint16_t target_gid_t;
+typedef int32_t  target_pid_t;
+
+#define ELF_NREG    18
+typedef elf_greg_t  elf_gregset_t[ELF_NREG];
+
+static void elf_core_copy_regs(elf_gregset_t *regs, const CPUState *env)
+{
+    (*regs)[0] = env->regs[0];
+    (*regs)[1] = env->regs[1];
+    (*regs)[2] = env->regs[2];
+    (*regs)[3] = env->regs[3];
+    (*regs)[4] = env->regs[4];
+    (*regs)[5] = env->regs[5];
+    (*regs)[6] = env->regs[6];
+    (*regs)[7] = env->regs[7];
+    (*regs)[8] = env->regs[8];
+    (*regs)[9] = env->regs[9];
+    (*regs)[10] = env->regs[10];
+    (*regs)[11] = env->regs[11];
+    (*regs)[12] = env->regs[12];
+    (*regs)[13] = env->regs[13];
+    (*regs)[14] = env->regs[14];
+    (*regs)[15] = env->regs[15];
+
+    (*regs)[16] = cpsr_read((CPUState *)env);
+    (*regs)[17] = env->regs[0]; /* XXX */
+}
+
 #define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE	4096
 
@@ -418,7 +454,6 @@ static inline void init_thread(struct target_pt_regs *_regs, struct image_info *
     _regs->gpr[5] = pos;
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE	4096
 
 #endif
@@ -448,7 +483,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
     regs->regs[29] = infop->start_stack;
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE        4096
 
 #endif /* TARGET_MIPS */
@@ -470,7 +504,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
 
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE        4096
 
 #endif /* TARGET_MICROBLAZE */
@@ -492,7 +525,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
   regs->regs[15] = infop->start_stack;
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE        4096
 
 #endif
@@ -512,7 +544,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
   regs->erp = infop->entry;
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE        8192
 
 #endif
@@ -537,7 +568,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
     regs->pc = infop->entry;
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE	8192
 
 #endif
@@ -562,7 +592,6 @@ static inline void init_thread(struct target_pt_regs *regs, struct image_info *i
            regs->unique, infop->start_data);
 }
 
-#define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE        8192
 
 #endif /* TARGET_ALPHA */
@@ -680,6 +709,20 @@ static void bswap_sym(struct elf_sym *sym)
 }
 #endif
 
+#ifdef USE_ELF_CORE_DUMP
+static int elf_core_dump(int, const CPUState *);
+
+#ifdef BSWAP_NEEDED
+static void bswap_note(struct elf_note *en)
+{
+    bswaptls(&en->n_namesz);
+    bswaptls(&en->n_descsz);
+    bswaptls(&en->n_type);
+}
+#endif /* BSWAP_NEEDED */
+
+#endif /* USE_ELF_CORE_DUMP */
+
 /*
  * 'copy_elf_strings()' copies argument/envelope strings from user
  * memory to free pages in kernel mem. These are in a format ready
@@ -904,6 +947,8 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
 #endif
 #undef NEW_AUX_ENT
 
+        info->saved_auxv = sp;
+
         sp = loader_build_argptr(envc, argc, sp, p, !ibcs);
         return sp;
 }
@@ -1586,9 +1631,876 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
 
     info->entry = elf_entry;
 
+#ifdef USE_ELF_CORE_DUMP
+    bprm->core_dump = &elf_core_dump;
+#endif
+
     return 0;
 }
 
+#ifdef USE_ELF_CORE_DUMP
+
+/*
+ * Definitions to generate Intel SVR4-like core files.
+ * These mostly have the same names as the SVR4 types with "elf_"
+ * tacked on the front to prevent clashes with linux definitions,
+ * and the typedef forms have been avoided.  This is mostly like
+ * the SVR4 structure, but more Linuxy, with things that Linux does
+ * not support and which gdb doesn't really use excluded.
+ *
+ * Fields we don't dump (their contents is zero) in linux-user qemu
+ * are marked with XXX.
+ *
+ * Core dump code is copied from linux kernel (fs/binfmt_elf.c).
+ *
+ * Porting ELF coredump for target is (quite) simple process.  First you
+ * define ELF_USE_CORE_DUMP in target ELF code (where init_thread() for
+ * the target resides):
+ *
+ * #define USE_ELF_CORE_DUMP
+ *
+ * Next you define type of register set used for dumping.  ELF specification
+ * says that it needs to be array of elf_greg_t that has size of ELF_NREG.
+ *
+ * typedef <target_regtype> elf_greg_t;
+ * #define ELF_NREG <number of registers>
+ * typedef elf_greg_t elf_gregset_t[ELF_NREG];
+ *
+ * Then define following types to match target types.  Actual types can
+ * be found from linux kernel (arch/<ARCH>/include/asm/posix_types.h):
+ *
+ * typedef <target_uid_type> target_uid_t;
+ * typedef <target_gid_type> target_gid_t;
+ * typedef <target_pid_type> target_pid_t;
+ *
+ * Last step is to implement target specific function that copies registers
+ * from given cpu into just specified register set.  Prototype is:
+ *
+ * static void elf_core_copy_regs(elf_gregset_t *regs, const CPUState *env);
+ *
+ * Parameters:
+ *     regs - copy register values into here (allocated and zeroed by caller)
+ *     env - copy registers from here
+ *
+ * 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;
+    void       *data;
+    size_t     notesz;
+};
+
+struct elf_siginfo {
+    int  si_signo; /* signal number */
+    int  si_code;  /* extra code */
+    int  si_errno; /* errno */
+};
+
+struct elf_prstatus {
+    struct elf_siginfo pr_info;      /* Info associated with signal */
+    short              pr_cursig;    /* Current signal */
+    target_ulong       pr_sigpend;   /* XXX */
+    target_ulong       pr_sighold;   /* XXX */
+    target_pid_t       pr_pid;
+    target_pid_t       pr_ppid;
+    target_pid_t       pr_pgrp;
+    target_pid_t       pr_sid;
+    struct target_timeval pr_utime;  /* XXX User time */
+    struct target_timeval pr_stime;  /* XXX System time */
+    struct target_timeval pr_cutime; /* XXX Cumulative user time */
+    struct target_timeval pr_cstime; /* XXX Cumulative system time */
+    elf_gregset_t      pr_reg;       /* GP registers */
+    int                pr_fpvalid;   /* XXX */
+};
+
+#define ELF_PRARGSZ     (80) /* Number of chars for args */
+
+struct elf_prpsinfo {
+    char         pr_state;       /* numeric process state */
+    char         pr_sname;       /* char for pr_state */
+    char         pr_zomb;        /* zombie */
+    char         pr_nice;        /* nice val */
+    target_ulong pr_flag;        /* flags */
+    target_uid_t pr_uid;
+    target_gid_t pr_gid;
+    target_pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid;
+    /* Lots missing */
+    char    pr_fname[16];           /* filename of executable */
+    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 {
+    TAILQ_ENTRY(elf_thread_status)  ets_link;
+    struct 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 elf_prstatus *prstatus;  /* NT_PRSTATUS */
+    struct elf_prpsinfo *psinfo;    /* NT_PRPSINFO */
+
+    TAILQ_HEAD(thread_list_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 {
+    abi_ulong   vma_start;  /* start vaddr of memory region */
+    abi_ulong   vma_end;    /* end vaddr of memory region */
+    abi_ulong   vma_flags;  /* protection etc. flags for the region */
+    TAILQ_ENTRY(vm_area_struct) vma_link;
+};
+
+struct mm_struct {
+    TAILQ_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 *, abi_ulong,
+    abi_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, unsigned long start, unsigned long 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 elf_prstatus *, const TaskState *, int);
+static int fill_psinfo(struct 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 CPUState *);
+static void fill_thread_info(struct elf_note_info *, const CPUState *);
+static int core_dump_filename(const TaskState *, char *, size_t);
+
+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 elf_prstatus *);
+static void bswap_psinfo(struct elf_prpsinfo *);
+
+static void bswap_prstatus(struct elf_prstatus *prstatus)
+{
+    prstatus->pr_info.si_signo = tswapl(prstatus->pr_info.si_signo);
+    prstatus->pr_info.si_code = tswapl(prstatus->pr_info.si_code);
+    prstatus->pr_info.si_errno = tswapl(prstatus->pr_info.si_errno);
+    prstatus->pr_cursig = tswap16(prstatus->pr_cursig);
+    prstatus->pr_sigpend = tswapl(prstatus->pr_sigpend);
+    prstatus->pr_sighold = tswapl(prstatus->pr_sighold);
+    prstatus->pr_pid = tswap32(prstatus->pr_pid);
+    prstatus->pr_ppid = tswap32(prstatus->pr_ppid);
+    prstatus->pr_pgrp = tswap32(prstatus->pr_pgrp);
+    prstatus->pr_sid = tswap32(prstatus->pr_sid);
+    /* cpu times are not filled, so we skip them */
+    /* regs should be in correct format already */
+    prstatus->pr_fpvalid = tswap32(prstatus->pr_fpvalid);
+}
+
+static void bswap_psinfo(struct elf_prpsinfo *psinfo)
+{
+    psinfo->pr_flag = tswapl(psinfo->pr_flag);
+    psinfo->pr_uid = tswap16(psinfo->pr_uid);
+    psinfo->pr_gid = tswap16(psinfo->pr_gid);
+    psinfo->pr_pid = tswap32(psinfo->pr_pid);
+    psinfo->pr_ppid = tswap32(psinfo->pr_ppid);
+    psinfo->pr_pgrp = tswap32(psinfo->pr_pgrp);
+    psinfo->pr_sid = tswap32(psinfo->pr_sid);
+}
+#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 = qemu_malloc(sizeof (*mm))) == NULL)
+        return (NULL);
+
+    mm->mm_count = 0;
+    TAILQ_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) {
+        TAILQ_REMOVE(&mm->mm_mmap, vma, vma_link);
+        qemu_free(vma);
+    }
+    qemu_free(mm);
+}
+
+static int vma_add_mapping(struct mm_struct *mm, abi_ulong start,
+    abi_ulong end, abi_ulong flags)
+{
+    struct vm_area_struct *vma;
+
+    if ((vma = qemu_mallocz(sizeof (*vma))) == NULL)
+        return (-1);
+
+    vma->vma_start = start;
+    vma->vma_end = end;
+    vma->vma_flags = flags;
+
+    TAILQ_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 (TAILQ_FIRST(&mm->mm_mmap));
+}
+
+static struct vm_area_struct *vma_next(struct vm_area_struct *vma)
+{
+    return (TAILQ_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)
+{
+    /* if we cannot even read the first page, skip it */
+    if (!access_ok(VERIFY_READ, vma->vma_start, TARGET_PAGE_SIZE))
+        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.
+     */
+    if (vma->vma_flags & PROT_EXEC) {
+        char page[TARGET_PAGE_SIZE];
+
+        copy_from_user(page, vma->vma_start, sizeof (page));
+        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);
+        }
+    }
+
+    return (vma->vma_end - vma->vma_start);
+}
+
+static int vma_walker(void *priv, unsigned long start, unsigned long end,
+    unsigned long flags)
+{
+    struct mm_struct *mm = (struct mm_struct *)priv;
+
+    /*
+     * Don't dump anything that qemu has reserved for internal use.
+     */
+    if (flags & PAGE_RESERVED)
+        return (0);
+
+    vma_add_mapping(mm, start, end, flags);
+    return (0);
+}
+
+static void fill_note(struct memelfnote *note, const char *name, int type,
+    unsigned int sz, void *data)
+{
+    unsigned int namesz;
+
+    namesz = strlen(name) + 1;
+    note->name = name;
+    note->namesz = namesz;
+    note->namesz_rounded = roundup(namesz, sizeof (int32_t));
+    note->type = type;
+    note->datasz = roundup(sz, sizeof (int32_t));;
+    note->data = data;
+
+    /*
+     * We calculate rounded up note size here as specified by
+     * ELF document.
+     */
+    note->notesz = sizeof (struct elf_note) +
+        note->namesz_rounded + note->datasz;
+}
+
+static void fill_elf_header(struct elfhdr *elf, int segs, uint16_t machine,
+    uint32_t flags)
+{
+    (void) memset(elf, 0, sizeof(*elf));
+
+    (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;
+    elf->e_ident[EI_OSABI] = ELF_OSABI;
+
+    elf->e_type = ET_CORE;
+    elf->e_machine = machine;
+    elf->e_version = EV_CURRENT;
+    elf->e_phoff = sizeof(struct elfhdr);
+    elf->e_flags = flags;
+    elf->e_ehsize = sizeof(struct elfhdr);
+    elf->e_phentsize = sizeof(struct elf_phdr);
+    elf->e_phnum = segs;
+
+#ifdef BSWAP_NEEDED
+    bswap_ehdr(elf);
+#endif
+}
+
+static void fill_elf_note_phdr(struct elf_phdr *phdr, int 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;
+
+#ifdef BSWAP_NEEDED
+    bswap_phdr(phdr);
+#endif
+}
+
+static size_t note_size(const struct memelfnote *note)
+{
+    return (note->notesz);
+}
+
+static void fill_prstatus(struct 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);
+
+#ifdef BSWAP_NEEDED
+    bswap_prstatus(prstatus);
+#endif
+}
+
+static int fill_psinfo(struct elf_prpsinfo *psinfo, const TaskState *ts)
+{
+    char *filename, *base_filename;
+    unsigned int i, len;
+
+    (void) memset(psinfo, 0, sizeof (*psinfo));
+
+    len = ts->info->arg_end - ts->info->arg_start;
+    if (len >= ELF_PRARGSZ)
+        len = ELF_PRARGSZ - 1;
+    if (copy_from_user(&psinfo->pr_psargs, ts->info->arg_start, 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();
+
+    filename = strdup(ts->bprm->filename);
+    base_filename = strdup(basename(filename));
+    (void) strncpy(psinfo->pr_fname, base_filename,
+        sizeof(psinfo->pr_fname));
+    free(base_filename);
+    free(filename);
+
+#ifdef BSWAP_NEEDED
+    bswap_psinfo(psinfo);
+#endif
+    return (0);
+}
+
+static void fill_auxv_note(struct memelfnote *note, const TaskState *ts)
+{
+    elf_addr_t auxv = (elf_addr_t)ts->info->saved_auxv;
+    elf_addr_t orig_auxv = auxv;
+    abi_ulong val;
+    void *ptr;
+    int i, 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.
+     */
+
+    /* find out lenght of the vector, AT_NULL is terminator */
+    i = len = 0;
+    do {
+        get_user_ual(val, auxv);
+        i += 2;
+        auxv += 2 * sizeof (elf_addr_t);
+    } while (val != AT_NULL);
+    len = i * sizeof (elf_addr_t);
+
+    /* 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);
+    }
+}
+
+/*
+ * Constructs name of coredump file.  We have following convention
+ * for the name:
+ *     qemu_<basename-of-target-binary>_<date>-<time>_<pid>.core
+ *
+ * Returns 0 in case of success, -1 otherwise (errno is set).
+ */
+static int core_dump_filename(const TaskState *ts, char *buf,
+    size_t bufsize)
+{
+    char timestamp[64];
+    char *filename = NULL;
+    char *base_filename = NULL;
+    struct timeval tv;
+    struct tm tm;
+
+    assert(bufsize >= PATH_MAX);
+
+    if (gettimeofday(&tv, NULL) < 0) {
+        (void) fprintf(stderr, "unable to get current timestamp: %s",
+            strerror(errno));
+        return (-1);
+    }
+
+    filename = strdup(ts->bprm->filename);
+    base_filename = strdup(basename(filename));
+    (void) strftime(timestamp, sizeof (timestamp), "%Y%m%d-%H%M%S",
+        localtime_r(&tv.tv_sec, &tm));
+    (void) snprintf(buf, bufsize, "qemu_%s_%s_%d.core",
+        base_filename, timestamp, (int)getpid());
+    free(base_filename);
+    free(filename);
+
+    return (0);
+}
+
+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 ;
+        }
+    }
+
+    /*
+     * In normal conditions, single write(2) should do but
+     * in case of socket etc. this mechanism is more portable.
+     */
+    do {
+        bytes_written = write(fd, bufp, bytes_left);
+        if (bytes_written < 0) {
+            if (errno == EINTR)
+                continue;
+            return (-1);
+        } else if (bytes_written == 0) { /* eof */
+            return (-1);
+        }
+        bufp += bytes_written;
+        bytes_left -= bytes_written;
+    } while (bytes_left > 0);
+
+    return (0);
+}
+
+static int write_note(struct memelfnote *men, int fd)
+{
+    struct elf_note en;
+
+    en.n_namesz = men->namesz;
+    en.n_type = men->type;
+    en.n_descsz = men->datasz;
+
+#ifdef BSWAP_NEEDED
+    bswap_note(&en);
+#endif
+
+    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) != 0)
+        return (-1);
+
+    return (0);
+}
+
+static void fill_thread_info(struct elf_note_info *info, const CPUState *env)
+{
+    TaskState *ts = (TaskState *)env->opaque;
+    struct elf_thread_status *ets;
+
+    ets = qemu_mallocz(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);
+
+    TAILQ_INSERT_TAIL(&info->thread_list, ets, ets_link);
+
+    info->notes_size += note_size(&ets->notes[0]);
+}
+
+static int fill_note_info(struct elf_note_info *info,
+    long signr, const CPUState *env)
+{
+#define NUMNOTES 3
+    CPUState *cpu = NULL;
+    TaskState *ts = (TaskState *)env->opaque;
+    int i;
+
+    (void) memset(info, 0, sizeof (*info));
+
+    TAILQ_INIT(&info->thread_list);
+
+    info->notes = qemu_mallocz(NUMNOTES * sizeof (struct memelfnote));
+    if (info->notes == NULL)
+        return (-ENOMEM);
+    info->prstatus = qemu_mallocz(sizeof (*info->prstatus));
+    if (info->prstatus == NULL)
+        return (-ENOMEM);
+    info->psinfo = qemu_mallocz(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 */
+    cpu_list_lock();
+    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        if (cpu == thread_env)
+            continue;
+        fill_thread_info(info, cpu);
+    }
+    cpu_list_unlock();
+
+    return (0);
+}
+
+static void free_note_info(struct elf_note_info *info)
+{
+    struct elf_thread_status *ets;
+
+    while (!TAILQ_EMPTY(&info->thread_list)) {
+        ets = TAILQ_FIRST(&info->thread_list);
+        TAILQ_REMOVE(&info->thread_list, ets, ets_link);
+        qemu_free(ets);
+    }
+
+    qemu_free(info->prstatus);
+    qemu_free(info->psinfo);
+    qemu_free(info->notes);
+}
+
+static int write_note_info(struct elf_note_info *info, int fd)
+{
+    struct elf_thread_status *ets;
+    int i, error = 0;
+
+    /* 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 */
+    for (ets = info->thread_list.tqh_first; ets != NULL;
+        ets = ets->ets_link.tqe_next) {
+        if ((error = write_note(&ets->notes[0], fd)) != 0)
+            return (error);
+    }
+
+    return (0);
+}
+
+/*
+ * Write out ELF coredump.
+ *
+ * See documentation of ELF object file format in:
+ * http://www.caldera.com/developers/devspecs/gabi41.pdf
+ *
+ * Coredump format in linux is following:
+ *
+ * 0   +----------------------+         \
+ *     | ELF header           | ET_CORE  |
+ *     +----------------------+          |
+ *     | ELF program headers  |          |--- headers
+ *     | - NOTE section       |          |
+ *     | - PT_LOAD sections   |          |
+ *     +----------------------+         /
+ *     | NOTEs:               |
+ *     | - NT_PRSTATUS        |
+ *     | - NT_PRSINFO         |
+ *     | - NT_AUXV            |
+ *     +----------------------+ <-- aligned to target page
+ *     | Process memory dump  |
+ *     :                      :
+ *     .                      .
+ *     :                      :
+ *     |                      |
+ *     +----------------------+
+ *
+ * NT_PRSTATUS -> struct elf_prstatus (per thread)
+ * NT_PRSINFO  -> struct elf_prpsinfo
+ * NT_AUXV is array of { type, value } pairs (see fill_auxv_note()).
+ *
+ * Format follows System V format as close as possible.  Current
+ * version limitations are as follows:
+ *     - no floating point registers are dumped
+ *
+ * Function returns 0 in case of success, negative errno otherwise.
+ *
+ * TODO: make this work also during runtime: it should be
+ * possible to force coredump from running process and then
+ * continue processing.  For example qemu could set up SIGUSR2
+ * handler (provided that target process haven't registered
+ * handler for that) that does the dump when signal is received.
+ */
+static int elf_core_dump(int signr, const CPUState *env)
+{
+    const TaskState *ts = (const TaskState *)env->opaque;
+    struct vm_area_struct *vma = NULL;
+    char corefile[PATH_MAX];
+    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;
+    int fd = -1;
+
+    errno = 0;
+    getrlimit(RLIMIT_CORE, &dumpsize);
+    if (dumpsize.rlim_cur == 0)
+       return 0;
+
+    if (core_dump_filename(ts, corefile, sizeof (corefile)) < 0)
+        return (-errno);
+
+    if ((fd = open(corefile, O_WRONLY | O_CREAT,
+        S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
+        return (-errno);
+
+    /*
+     * Walk through target process memory mappings and
+     * set up structure containing this information.  After
+     * this point vma_xxx functions can be used.
+     */
+    if ((mm = vma_init()) == NULL)
+        goto out;
+
+    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;
+
+    /* fill in in-memory version of notes */
+    if (fill_note_info(&info, signr, env) < 0)
+        goto out;
+
+    offset += sizeof (elf);                             /* elf header */
+    offset += (segs + 1) * sizeof (struct elf_phdr);    /* program headers */
+
+    /* write out notes program header */
+    fill_elf_note_phdr(&phdr, info.notes_size, offset);
+
+    offset += info.notes_size;
+    if (dump_write(fd, &phdr, sizeof (phdr)) != 0)
+        goto out;
+
+    /*
+     * ELF specification wants data to start at page boundary so
+     * we align it here.
+     */
+    offset = roundup(offset, ELF_EXEC_PAGESIZE);
+
+    /*
+     * 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;
+
+        dump_write(fd, &phdr, sizeof (phdr));
+    }
+
+    /*
+     * Next we write notes just after program headers.  No
+     * alignment needed here.
+     */
+    if (write_note_info(&info, fd) < 0)
+        goto out;
+
+    /* align data to page boundary */
+    data_offset = lseek(fd, 0, SEEK_CUR);
+    data_offset = TARGET_PAGE_ALIGN(data_offset);
+    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_FMT_lx "\n",
+                    addr);
+                errno = -error;
+                goto out;
+            }
+            if (dump_write(fd, page, TARGET_PAGE_SIZE) < 0)
+                goto out;
+        }
+    }
+
+out:
+    free_note_info(&info);
+    if (mm != NULL)
+        vma_delete(mm);
+    (void) close(fd);
+
+    if (errno != 0)
+        return (-errno);
+    return (0);
+}
+
+#endif /* USE_ELF_CORE_DUMP */
+
 static int load_aout_interp(void * exptr, int interp_fd)
 {
     printf("a.out interpreter not yet supported\n");
diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c
index ada7c697d2..14c433ea23 100644
--- a/linux-user/linuxload.c
+++ b/linux-user/linuxload.c
@@ -115,6 +115,7 @@ static int prepare_binprm(struct linux_binprm *bprm)
 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
                               abi_ulong stringp, int push_ptr)
 {
+    TaskState *ts = (TaskState *)thread_env->opaque;
     int n = sizeof(abi_ulong);
     abi_ulong envp;
     abi_ulong argv;
@@ -133,13 +134,14 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
     sp -= n;
     /* FIXME - handle put_user() failures */
     put_user_ual(argc, sp);
-
+    ts->info->arg_start = stringp;
     while (argc-- > 0) {
         /* FIXME - handle put_user() failures */
         put_user_ual(stringp, argv);
         argv += n;
         stringp += target_strlen(stringp) + 1;
     }
+    ts->info->arg_end = stringp;
     /* FIXME - handle put_user() failures */
     put_user_ual(0, argv);
     while (envc-- > 0) {
@@ -155,45 +157,45 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 }
 
 int loader_exec(const char * filename, char ** argv, char ** envp,
-             struct target_pt_regs * regs, struct image_info *infop)
+             struct target_pt_regs * regs, struct image_info *infop,
+             struct linux_binprm *bprm)
 {
-    struct linux_binprm bprm;
     int retval;
     int i;
 
-    bprm.p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
+    bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
     for (i=0 ; i<MAX_ARG_PAGES ; i++)       /* clear page-table */
-            bprm.page[i] = 0;
+            bprm->page[i] = 0;
     retval = open(filename, O_RDONLY);
     if (retval < 0)
         return retval;
-    bprm.fd = retval;
-    bprm.filename = (char *)filename;
-    bprm.argc = count(argv);
-    bprm.argv = argv;
-    bprm.envc = count(envp);
-    bprm.envp = envp;
+    bprm->fd = retval;
+    bprm->filename = (char *)filename;
+    bprm->argc = count(argv);
+    bprm->argv = argv;
+    bprm->envc = count(envp);
+    bprm->envp = envp;
 
-    retval = prepare_binprm(&bprm);
+    retval = prepare_binprm(bprm);
 
     infop->host_argv = argv;
 
     if(retval>=0) {
-        if (bprm.buf[0] == 0x7f
-                && bprm.buf[1] == 'E'
-                && bprm.buf[2] == 'L'
-                && bprm.buf[3] == 'F') {
+        if (bprm->buf[0] == 0x7f
+                && bprm->buf[1] == 'E'
+                && bprm->buf[2] == 'L'
+                && bprm->buf[3] == 'F') {
 #ifndef TARGET_HAS_ELFLOAD32
-            retval = load_elf_binary(&bprm,regs,infop);
+            retval = load_elf_binary(bprm,regs,infop);
 #else
-            retval = load_elf_binary_multi(&bprm, regs, infop);
+            retval = load_elf_binary_multi(bprm, regs, infop);
 #endif
 #if defined(TARGET_HAS_BFLT)
-        } else if (bprm.buf[0] == 'b'
-                && bprm.buf[1] == 'F'
-                && bprm.buf[2] == 'L'
-                && bprm.buf[3] == 'T') {
-            retval = load_flt_binary(&bprm,regs,infop);
+        } else if (bprm->buf[0] == 'b'
+                && bprm->buf[1] == 'F'
+                && bprm->buf[2] == 'L'
+                && bprm->buf[3] == 'T') {
+            retval = load_flt_binary(bprm,regs,infop);
 #endif
         } else {
             fprintf(stderr, "Unknown binary format\n");
@@ -209,7 +211,7 @@ int loader_exec(const char * filename, char ** argv, char ** envp,
 
     /* Something went wrong, return the inode and free the argument pages*/
     for (i=0 ; i<MAX_ARG_PAGES ; i++) {
-        free(bprm.page[i]);
+        free(bprm->page[i]);
     }
     return(retval);
 }
diff --git a/linux-user/main.c b/linux-user/main.c
index 4832d3f860..7eabd0c22f 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <sys/syscall.h>
 
 #include "qemu.h"
 #include "qemu-common.h"
@@ -2319,6 +2320,27 @@ static void usage(void)
 
 THREAD CPUState *thread_env;
 
+void task_settid(TaskState *ts)
+{
+    if (ts->ts_tid == 0) {
+#ifdef USE_NPTL
+        ts->ts_tid = (pid_t)syscall(SYS_gettid);
+#else
+        /* when no threads are used, tid becomes pid */
+        ts->ts_tid = getpid();
+#endif
+    }
+}
+
+void stop_all_tasks(void)
+{
+    /*
+     * We trust that when using NPTL, start_exclusive()
+     * handles thread stopping correctly.
+     */
+    start_exclusive();
+}
+
 /* Assumes contents are already zeroed.  */
 void init_task_state(TaskState *ts)
 {
@@ -2338,6 +2360,7 @@ int main(int argc, char **argv, char **envp)
     const char *cpu_model;
     struct target_pt_regs regs1, *regs = &regs1;
     struct image_info info1, *info = &info1;
+    struct linux_binprm bprm;
     TaskState ts1, *ts = &ts1;
     CPUState *env;
     int optind;
@@ -2467,6 +2490,8 @@ int main(int argc, char **argv, char **envp)
     /* Zero out image_info */
     memset(info, 0, sizeof(struct image_info));
 
+    memset(&bprm, 0, sizeof (bprm));
+
     /* Scan interp_prefix dir for replacement files. */
     init_paths(interp_prefix);
 
@@ -2543,7 +2568,16 @@ int main(int argc, char **argv, char **envp)
     }
     target_argv[target_argc] = NULL;
 
-    if (loader_exec(filename, target_argv, target_environ, regs, info) != 0) {
+    memset(ts, 0, sizeof(TaskState));
+    init_task_state(ts);
+    /* build Task State */
+    ts->info = info;
+    ts->bprm = &bprm;
+    env->opaque = ts;
+    task_settid(ts);
+
+    if (loader_exec(filename, target_argv, target_environ, regs,
+        info, &bprm) != 0) {
         printf("Error loading %s\n", filename);
         _exit(1);
     }
@@ -2579,12 +2613,6 @@ int main(int argc, char **argv, char **envp)
     syscall_init();
     signal_init();
 
-    /* build Task State */
-    memset(ts, 0, sizeof(TaskState));
-    init_task_state(ts);
-    ts->info = info;
-    env->opaque = ts;
-
 #if defined(TARGET_I386)
     cpu_x86_set_cpl(env, 3);
 
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index d83a2a4b3d..e04a31c69c 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -18,6 +18,7 @@
 #include "syscall.h"
 #include "target_signal.h"
 #include "gdbstub.h"
+#include "sys-queue.h"
 
 #if defined(USE_NPTL)
 #define THREAD __thread
@@ -44,6 +45,9 @@ struct image_info {
         abi_ulong       entry;
         abi_ulong       code_offset;
         abi_ulong       data_offset;
+        abi_ulong       saved_auxv;
+        abi_ulong       arg_start;
+        abi_ulong       arg_end;
         char            **host_argv;
 	int		personality;
 };
@@ -87,7 +91,7 @@ struct emulated_sigtable {
 /* NOTE: we force a big alignment so that the stack stored after is
    aligned too */
 typedef struct TaskState {
-    struct TaskState *next;
+    pid_t ts_tid;     /* tid (or pid) of this task */
 #ifdef TARGET_ARM
     /* FPA state */
     FPA11 fpa;
@@ -114,6 +118,7 @@ typedef struct TaskState {
 #endif
     int used; /* non zero if used */
     struct image_info *info;
+    struct linux_binprm *bprm;
 
     struct emulated_sigtable sigtab[TARGET_NSIG];
     struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
@@ -125,6 +130,8 @@ typedef struct TaskState {
 
 extern char *exec_path;
 void init_task_state(TaskState *ts);
+void task_settid(TaskState *);
+void stop_all_tasks(void);
 extern const char *qemu_uname_release;
 
 /* ??? See if we can avoid exposing so much of the loader internals.  */
@@ -149,13 +156,15 @@ struct linux_binprm {
         char **argv;
         char **envp;
         char * filename;        /* Name of binary */
+        int (*core_dump)(int, const CPUState *); /* coredump routine */
 };
 
 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
                               abi_ulong stringp, int push_ptr);
 int loader_exec(const char * filename, char ** argv, char ** envp,
-             struct target_pt_regs * regs, struct image_info *infop);
+             struct target_pt_regs * regs, struct image_info *infop,
+             struct linux_binprm *);
 
 int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
                     struct image_info * info);
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 371927e2a2..6a34171aa0 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -27,6 +27,7 @@
 #include <errno.h>
 #include <assert.h>
 #include <sys/ucontext.h>
+#include <sys/resource.h>
 
 #include "qemu.h"
 #include "qemu-common.h"
@@ -287,6 +288,23 @@ static int fatal_signal (int sig)
     }
 }
 
+/* returns 1 if given signal should dump core if not handled */
+static int core_dump_signal(int sig)
+{
+    switch (sig) {
+    case TARGET_SIGABRT:
+    case TARGET_SIGFPE:
+    case TARGET_SIGILL:
+    case TARGET_SIGQUIT:
+    case TARGET_SIGSEGV:
+    case TARGET_SIGTRAP:
+    case TARGET_SIGBUS:
+        return (1);
+    default:
+        return (0);
+    }
+}
+
 void signal_init(void)
 {
     struct sigaction act;
@@ -352,13 +370,29 @@ static inline void free_sigqueue(CPUState *env, struct sigqueue *q)
 /* abort execution with signal */
 static void QEMU_NORETURN force_sig(int sig)
 {
-    int host_sig;
+    TaskState *ts = (TaskState *)thread_env->opaque;
+    int host_sig, core_dumped = 0;
     struct sigaction act;
     host_sig = target_to_host_signal(sig);
-    fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
-            sig, strsignal(host_sig));
     gdb_signalled(thread_env, sig);
 
+    /* dump core if supported by target binary format */
+    if (core_dump_signal(sig) && (ts->bprm->core_dump != NULL)) {
+        stop_all_tasks();
+        core_dumped =
+            ((*ts->bprm->core_dump)(sig, thread_env) == 0);
+    }
+    if (core_dumped) {
+        /* we already dumped the core of target process, we don't want
+         * a coredump of qemu itself */
+        struct rlimit nodump;
+        getrlimit(RLIMIT_CORE, &nodump);
+        nodump.rlim_cur=0;
+        setrlimit(RLIMIT_CORE, &nodump);
+        (void) fprintf(stderr, "qemu: uncaught target signal %d (%s) - %s\n",
+            sig, strsignal(host_sig), "core dumped" );
+    }
+
     /* The proper exit code for dieing from an uncaught signal is
      * -<signal>.  The kernel doesn't allow exit() or _exit() to pass
      * a negative value.  To get the proper exit code we need to
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 47d03f7f8d..56f2a3f7c6 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -3379,11 +3379,14 @@ static void *clone_func(void *arg)
 {
     new_thread_info *info = arg;
     CPUState *env;
+    TaskState *ts;
 
     env = info->env;
     thread_env = env;
+    ts = (TaskState *)thread_env->opaque;
     info->tid = gettid();
     env->host_tid = info->tid;
+    task_settid(ts);
     if (info->child_tidptr)
         put_user_u32(info->tid, info->child_tidptr);
     if (info->parent_tidptr)
@@ -3435,6 +3438,7 @@ static int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp,
         flags &= ~(CLONE_VFORK | CLONE_VM);
 
     if (flags & CLONE_VM) {
+        TaskState *parent_ts = (TaskState *)env->opaque;
 #if defined(USE_NPTL)
         new_thread_info info;
         pthread_attr_t attr;
@@ -3447,6 +3451,8 @@ static int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp,
         /* Init regs that differ from the parent.  */
         cpu_clone_regs(new_env, newsp);
         new_env->opaque = ts;
+        ts->bprm = parent_ts->bprm;
+        ts->info = parent_ts->info;
 #if defined(USE_NPTL)
         nptl_flags = flags;
         flags &= ~CLONE_NPTL_FLAGS2;