Merge commit 'v2.6.30' into for-2.6.31
[safe/jmp/linux-2.6] / fs / binfmt_elf.c
index b25707f..40381df 100644 (file)
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
-#include <linux/stat.h>
-#include <linux/time.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
-#include <linux/a.out.h>
 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/binfmts.h>
 #include <linux/string.h>
 #include <linux/file.h>
-#include <linux/fcntl.h>
-#include <linux/ptrace.h>
 #include <linux/slab.h>
-#include <linux/shm.h>
 #include <linux/personality.h>
 #include <linux/elfcore.h>
 #include <linux/init.h>
 #include <linux/highuid.h>
-#include <linux/smp.h>
 #include <linux/compiler.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 #include <linux/security.h>
-#include <linux/syscalls.h>
 #include <linux/random.h>
 #include <linux/elf.h>
 #include <linux/utsname.h>
@@ -132,6 +124,15 @@ static int padzero(unsigned long elf_bss)
 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
 #endif
 
+#ifndef ELF_BASE_PLATFORM
+/*
+ * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
+ * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
+ * will be copied to the user stack in the same manner as AT_PLATFORM.
+ */
+#define ELF_BASE_PLATFORM NULL
+#endif
+
 static int
 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
                unsigned long load_addr, unsigned long interp_load_addr)
@@ -143,11 +144,15 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
        elf_addr_t __user *envp;
        elf_addr_t __user *sp;
        elf_addr_t __user *u_platform;
+       elf_addr_t __user *u_base_platform;
+       elf_addr_t __user *u_rand_bytes;
        const char *k_platform = ELF_PLATFORM;
+       const char *k_base_platform = ELF_BASE_PLATFORM;
+       unsigned char k_rand_bytes[16];
        int items;
        elf_addr_t *elf_info;
        int ei_index = 0;
-       struct task_struct *tsk = current;
+       const struct cred *cred = current_cred();
        struct vm_area_struct *vma;
 
        /*
@@ -173,6 +178,28 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
                        return -EFAULT;
        }
 
+       /*
+        * If this architecture has a "base" platform capability
+        * string, copy it to userspace.
+        */
+       u_base_platform = NULL;
+       if (k_base_platform) {
+               size_t len = strlen(k_base_platform) + 1;
+
+               u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
+               if (__copy_to_user(u_base_platform, k_base_platform, len))
+                       return -EFAULT;
+       }
+
+       /*
+        * Generate 16 random bytes for userspace PRNG seeding.
+        */
+       get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
+       u_rand_bytes = (elf_addr_t __user *)
+                      STACK_ALLOC(p, sizeof(k_rand_bytes));
+       if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
+               return -EFAULT;
+
        /* Create the ELF interpreter info */
        elf_info = (elf_addr_t *)current->mm->saved_auxv;
        /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
@@ -200,15 +227,21 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
        NEW_AUX_ENT(AT_BASE, interp_load_addr);
        NEW_AUX_ENT(AT_FLAGS, 0);
        NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
-       NEW_AUX_ENT(AT_UID, tsk->uid);
-       NEW_AUX_ENT(AT_EUID, tsk->euid);
-       NEW_AUX_ENT(AT_GID, tsk->gid);
-       NEW_AUX_ENT(AT_EGID, tsk->egid);
+       NEW_AUX_ENT(AT_UID, cred->uid);
+       NEW_AUX_ENT(AT_EUID, cred->euid);
+       NEW_AUX_ENT(AT_GID, cred->gid);
+       NEW_AUX_ENT(AT_EGID, cred->egid);
        NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
+       NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
+       NEW_AUX_ENT(AT_EXECFN, bprm->exec);
        if (k_platform) {
                NEW_AUX_ENT(AT_PLATFORM,
                            (elf_addr_t)(unsigned long)u_platform);
        }
+       if (k_base_platform) {
+               NEW_AUX_ENT(AT_BASE_PLATFORM,
+                           (elf_addr_t)(unsigned long)u_base_platform);
+       }
        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
                NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
        }
@@ -256,7 +289,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
                        return -EFAULT;
                len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
                if (!len || len > MAX_ARG_STRLEN)
-                       return 0;
+                       return -EINVAL;
                p += len;
        }
        if (__put_user(0, argv))
@@ -268,7 +301,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
                        return -EFAULT;
                len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
                if (!len || len > MAX_ARG_STRLEN)
-                       return 0;
+                       return -EINVAL;
                p += len;
        }
        if (__put_user(0, envp))
@@ -536,7 +569,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
        unsigned long error;
        struct elf_phdr *elf_ppnt, *elf_phdata;
        unsigned long elf_bss, elf_brk;
-       int elf_exec_fileno;
        int retval, i;
        unsigned int size;
        unsigned long elf_entry;
@@ -548,7 +580,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
        struct {
                struct elfhdr elf_ex;
                struct elfhdr interp_elf_ex;
-               struct exec interp_ex;
        } *loc;
 
        loc = kmalloc(sizeof(*loc), GFP_KERNEL);
@@ -592,12 +623,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
                goto out_free_ph;
        }
 
-       retval = get_unused_fd();
-       if (retval < 0)
-               goto out_free_ph;
-       get_file(bprm->file);
-       fd_install(elf_exec_fileno = retval, bprm->file);
-
        elf_ppnt = elf_phdata;
        elf_bss = 0;
        elf_brk = 0;
@@ -616,13 +641,13 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
                        retval = -ENOEXEC;
                        if (elf_ppnt->p_filesz > PATH_MAX || 
                            elf_ppnt->p_filesz < 2)
-                               goto out_free_file;
+                               goto out_free_ph;
 
                        retval = -ENOMEM;
                        elf_interpreter = kmalloc(elf_ppnt->p_filesz,
                                                  GFP_KERNEL);
                        if (!elf_interpreter)
-                               goto out_free_file;
+                               goto out_free_ph;
 
                        retval = kernel_read(bprm->file, elf_ppnt->p_offset,
                                             elf_interpreter,
@@ -656,7 +681,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
                         * switch really is going to happen - do this in
                         * flush_thread().      - akpm
                         */
-                       SET_PERSONALITY(loc->elf_ex, 0);
+                       SET_PERSONALITY(loc->elf_ex);
 
                        interpreter = open_exec(elf_interpreter);
                        retval = PTR_ERR(interpreter);
@@ -680,7 +705,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
                        }
 
                        /* Get the exec headers */
-                       loc->interp_ex = *((struct exec *)bprm->buf);
                        loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
                        break;
                }
@@ -708,7 +732,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
                        goto out_free_dentry;
        } else {
                /* Executables without an interpreter also need a personality  */
-               SET_PERSONALITY(loc->elf_ex, 0);
+               SET_PERSONALITY(loc->elf_ex);
        }
 
        /* Flush all traces of the currently running executable */
@@ -722,7 +746,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 
        /* Do this immediately, since STACK_TOP as used in setup_arg_pages
           may depend on the personality.  */
-       SET_PERSONALITY(loc->elf_ex, 0);
+       SET_PERSONALITY(loc->elf_ex);
        if (elf_read_implies_exec(loc->elf_ex, executable_stack))
                current->personality |= READ_IMPLIES_EXEC;
 
@@ -918,19 +942,17 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 
        kfree(elf_phdata);
 
-       sys_close(elf_exec_fileno);
-
        set_binfmt(&elf_format);
 
 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
-       retval = arch_setup_additional_pages(bprm, executable_stack);
+       retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
        if (retval < 0) {
                send_sig(SIGKILL, current, 0);
                goto out;
        }
 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
 
-       compute_creds(bprm);
+       install_exec_creds(bprm);
        current->flags &= ~PF_FORKNOEXEC;
        retval = create_elf_tables(bprm, &loc->elf_ex,
                          load_addr, interp_load_addr);
@@ -977,12 +999,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 #endif
 
        start_thread(regs, elf_entry, bprm->p);
-       if (unlikely(current->ptrace & PT_PTRACED)) {
-               if (current->ptrace & PT_TRACE_EXEC)
-                       ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
-               else
-                       send_sig(SIGTRAP, current, 0);
-       }
        retval = 0;
 out:
        kfree(loc);
@@ -996,8 +1012,6 @@ out_free_dentry:
                fput(interpreter);
 out_free_interp:
        kfree(elf_interpreter);
-out_free_file:
-       sys_close(elf_exec_fileno);
 out_free_ph:
        kfree(elf_phdata);
        goto out;
@@ -1136,16 +1150,24 @@ static int dump_seek(struct file *file, loff_t off)
 static unsigned long vma_dump_size(struct vm_area_struct *vma,
                                   unsigned long mm_flags)
 {
+#define FILTER(type)   (mm_flags & (1UL << MMF_DUMP_##type))
+
        /* The vma can be set up to tell us the answer directly.  */
        if (vma->vm_flags & VM_ALWAYSDUMP)
                goto whole;
 
+       /* Hugetlb memory check */
+       if (vma->vm_flags & VM_HUGETLB) {
+               if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
+                       goto whole;
+               if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
+                       goto whole;
+       }
+
        /* Do not dump I/O mapped devices or special mappings */
        if (vma->vm_flags & (VM_IO | VM_RESERVED))
                return 0;
 
-#define FILTER(type)   (mm_flags & (1UL << MMF_DUMP_##type))
-
        /* By default, dump shared memory if mapped from an anonymous file. */
        if (vma->vm_flags & VM_SHARED) {
                if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
@@ -1168,9 +1190,11 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
         * check for an ELF header.  If we find one, dump the first page to
         * aid in determining what was mapped here.
         */
-       if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
+       if (FILTER(ELF_HEADERS) &&
+           vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
                u32 __user *header = (u32 __user *) vma->vm_start;
                u32 word;
+               mm_segment_t fs = get_fs();
                /*
                 * Doing it this way gets the constant folded by GCC.
                 */
@@ -1183,7 +1207,15 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
                magic.elfmag[EI_MAG1] = ELFMAG1;
                magic.elfmag[EI_MAG2] = ELFMAG2;
                magic.elfmag[EI_MAG3] = ELFMAG3;
-               if (get_user(word, header) == 0 && word == magic.cmp)
+               /*
+                * Switch to the user "segment" for get_user(),
+                * then put back what elf_core_dump() had in place.
+                */
+               set_fs(USER_DS);
+               if (unlikely(get_user(word, header)))
+                       word = 0;
+               set_fs(fs);
+               if (word == magic.cmp)
                        return PAGE_SIZE;
        }
 
@@ -1313,20 +1345,15 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
        prstatus->pr_pgrp = task_pgrp_vnr(p);
        prstatus->pr_sid = task_session_vnr(p);
        if (thread_group_leader(p)) {
+               struct task_cputime cputime;
+
                /*
-                * This is the record for the group leader.  Add in the
-                * cumulative times of previous dead threads.  This total
-                * won't include the time of each live thread whose state
-                * is included in the core dump.  The final total reported
-                * to our parent process when it calls wait4 will include
-                * those sums as well as the little bit more time it takes
-                * this and each other thread to finish dying after the
-                * core dump synchronization phase.
+                * This is the record for the group leader.  It shows the
+                * group-wide total, not its individual thread total.
                 */
-               cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
-                                  &prstatus->pr_utime);
-               cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
-                                  &prstatus->pr_stime);
+               thread_group_cputime(p, &cputime);
+               cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
+               cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
        } else {
                cputime_to_timeval(p->utime, &prstatus->pr_utime);
                cputime_to_timeval(p->stime, &prstatus->pr_stime);
@@ -1338,6 +1365,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
                       struct mm_struct *mm)
 {
+       const struct cred *cred;
        unsigned int i, len;
        
        /* first copy the parameters from user space */
@@ -1365,8 +1393,11 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
        psinfo->pr_nice = task_nice(p);
        psinfo->pr_flag = p->flags;
-       SET_UID(psinfo->pr_uid, p->uid);
-       SET_GID(psinfo->pr_gid, p->gid);
+       rcu_read_lock();
+       cred = __task_cred(p);
+       SET_UID(psinfo->pr_uid, cred->uid);
+       SET_GID(psinfo->pr_gid, cred->gid);
+       rcu_read_unlock();
        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
        
        return 0;
@@ -1480,7 +1511,7 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
        const struct user_regset_view *view = task_user_regset_view(dump_task);
        struct elf_thread_core_info *t;
        struct elf_prpsinfo *psinfo;
-       struct task_struct *g, *p;
+       struct core_thread *ct;
        unsigned int i;
 
        info->size = 0;
@@ -1519,31 +1550,26 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
        /*
         * Allocate a structure for each thread.
         */
-       rcu_read_lock();
-       do_each_thread(g, p)
-               if (p->mm == dump_task->mm) {
-                       t = kzalloc(offsetof(struct elf_thread_core_info,
-                                            notes[info->thread_notes]),
-                                   GFP_ATOMIC);
-                       if (unlikely(!t)) {
-                               rcu_read_unlock();
-                               return 0;
-                       }
-                       t->task = p;
-                       if (p == dump_task || !info->thread) {
-                               t->next = info->thread;
-                               info->thread = t;
-                       } else {
-                               /*
-                                * Make sure to keep the original task at
-                                * the head of the list.
-                                */
-                               t->next = info->thread->next;
-                               info->thread->next = t;
-                       }
+       for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
+               t = kzalloc(offsetof(struct elf_thread_core_info,
+                                    notes[info->thread_notes]),
+                           GFP_KERNEL);
+               if (unlikely(!t))
+                       return 0;
+
+               t->task = ct->task;
+               if (ct->task == dump_task || !info->thread) {
+                       t->next = info->thread;
+                       info->thread = t;
+               } else {
+                       /*
+                        * Make sure to keep the original task at
+                        * the head of the list.
+                        */
+                       t->next = info->thread->next;
+                       info->thread->next = t;
                }
-       while_each_thread(g, p);
-       rcu_read_unlock();
+       }
 
        /*
         * Now fill in each thread's information.
@@ -1690,7 +1716,6 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
 {
 #define        NUM_NOTES       6
        struct list_head *t;
-       struct task_struct *g, *p;
 
        info->notes = NULL;
        info->prstatus = NULL;
@@ -1722,20 +1747,19 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
 
        info->thread_status_size = 0;
        if (signr) {
+               struct core_thread *ct;
                struct elf_thread_status *ets;
-               rcu_read_lock();
-               do_each_thread(g, p)
-                       if (current->mm == p->mm && current != p) {
-                               ets = kzalloc(sizeof(*ets), GFP_ATOMIC);
-                               if (!ets) {
-                                       rcu_read_unlock();
-                                       return 0;
-                               }
-                               ets->thread = p;
-                               list_add(&ets->list, &info->thread_list);
-                       }
-               while_each_thread(g, p);
-               rcu_read_unlock();
+
+               for (ct = current->mm->core_state->dumper.next;
+                                               ct; ct = ct->next) {
+                       ets = kzalloc(sizeof(*ets), GFP_KERNEL);
+                       if (!ets)
+                               return 0;
+
+                       ets->thread = ct->task;
+                       list_add(&ets->list, &info->thread_list);
+               }
+
                list_for_each(t, &info->thread_list) {
                        int sz;
 
@@ -1900,7 +1924,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
        /* alloc memory for large data structures: too large to be on stack */
        elf = kmalloc(sizeof(*elf), GFP_KERNEL);
        if (!elf)
-               goto cleanup;
+               goto out;
        
        segs = current->mm->map_count;
 #ifdef ELF_CORE_EXTRA_PHDRS
@@ -2034,8 +2058,9 @@ end_coredump:
        set_fs(fs);
 
 cleanup:
-       kfree(elf);
        free_note_info(&info);
+       kfree(elf);
+out:
        return has_dumped;
 }