arch/powerpc/platforms/cell/spufs/coredump.c

   1 /*
   2  * SPU core dump code
   3  *
   4  * (C) Copyright 2006 IBM Corp.
   5  *
   6  * Author: Dwayne Grant McConnell <decimal@us.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/elf.h>
  24 #include <linux/file.h>
  25 #include <linux/fdtable.h>
  26 #include <linux/fs.h>
  27 #include <linux/gfp.h>
  28 #include <linux/list.h>
  29 #include <linux/syscalls.h>
  30 #include <linux/coredump.h>
  31 #include <linux/binfmts.h>
  32
  33 #include <linux/uaccess.h>
  34
  35 #include "spufs.h"
  36
  37 static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
  38                                 size_t size, loff_t *off)
  39 {
  40         u64 data;
  41         int ret;
  42
  43         if (spufs_coredump_read[num].read)
  44                 return spufs_coredump_read[num].read(ctx, buffer, size, off);
  45
  46         data = spufs_coredump_read[num].get(ctx);
  47         ret = snprintf(buffer, size, "0x%.16llx", data);
  48         if (ret >= size)
  49                 return size;
  50         return ++ret; /* count trailing NULL */
  51 }
  52
  53 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
  54 {
  55         int i, sz, total = 0;
  56         char *name;
  57         char fullname[80];
  58
  59         for (i = 0; spufs_coredump_read[i].name != NULL; i++) {
  60                 name = spufs_coredump_read[i].name;
  61                 sz = spufs_coredump_read[i].size;
  62
  63                 sprintf(fullname, "SPU/%d/%s", dfd, name);
  64
  65                 total += sizeof(struct elf_note);
  66                 total += roundup(strlen(fullname) + 1, 4);
  67                 total += roundup(sz, 4);
  68         }
  69
  70         return total;
  71 }
  72
  73 static int match_context(const void *v, struct file *file, unsigned fd)
  74 {
  75         struct spu_context *ctx;
  76         if (file->f_op != &spufs_context_fops)
  77                 return 0;
  78         ctx = SPUFS_I(file_inode(file))->i_ctx;
  79         if (ctx->flags & SPU_CREATE_NOSCHED)
  80                 return 0;
  81         return fd + 1;
  82 }
  83
  84 /*
  85  * The additional architecture-specific notes for Cell are various
  86  * context files in the spu context.
  87  *
  88  * This function iterates over all open file descriptors and sees
  89  * if they are a directory in spufs.  In that case we use spufs
  90  * internal functionality to dump them without needing to actually
  91  * open the files.
  92  */
  93 /*
  94  * descriptor table is not shared, so files can't change or go away.
  95  */
  96 static struct spu_context *coredump_next_context(int *fd)
  97 {
  98         struct file *file;
  99         int n = iterate_fd(current->files, *fd, match_context, NULL);
 100         if (!n)
 101                 return NULL;
 102         *fd = n - 1;
 103         file = fcheck(*fd);
 104         return SPUFS_I(file_inode(file))->i_ctx;
 105 }
 106
 107 int spufs_coredump_extra_notes_size(void)
 108 {
 109         struct spu_context *ctx;
 110         int size = 0, rc, fd;
 111
 112         fd = 0;
 113         while ((ctx = coredump_next_context(&fd)) != NULL) {
 114                 rc = spu_acquire_saved(ctx);
 115                 if (rc)
 116                         break;
 117                 rc = spufs_ctx_note_size(ctx, fd);
 118                 spu_release_saved(ctx);
 119                 if (rc < 0)
 120                         break;
 121
 122                 size += rc;
 123
 124                 /* start searching the next fd next time */
 125                 fd++;
 126         }
 127
 128         return size;
 129 }
 130
 131 static int spufs_arch_write_note(struct spu_context *ctx, int i,
 132                                   struct coredump_params *cprm, int dfd)
 133 {
 134         loff_t pos = 0;
 135         int sz, rc, total = 0;
 136         const int bufsz = PAGE_SIZE;
 137         char *name;
 138         char fullname[80], *buf;
 139         struct elf_note en;
 140         size_t skip;
 141
 142         buf = (void *)get_zeroed_page(GFP_KERNEL);
 143         if (!buf)
 144                 return -ENOMEM;
 145
 146         name = spufs_coredump_read[i].name;
 147         sz = spufs_coredump_read[i].size;
 148
 149         sprintf(fullname, "SPU/%d/%s", dfd, name);
 150         en.n_namesz = strlen(fullname) + 1;
 151         en.n_descsz = sz;
 152         en.n_type = NT_SPU;
 153
 154         if (!dump_emit(cprm, &en, sizeof(en)))
 155                 goto Eio;
 156
 157         if (!dump_emit(cprm, fullname, en.n_namesz))
 158                 goto Eio;
 159
 160         if (!dump_align(cprm, 4))
 161                 goto Eio;
 162
 163         do {
 164                 rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
 165                 if (rc > 0) {
 166                         if (!dump_emit(cprm, buf, rc))
 167                                 goto Eio;
 168                         total += rc;
 169                 }
 170         } while (rc == bufsz && total < sz);
 171
 172         if (rc < 0)
 173                 goto out;
 174
 175         skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;
 176         if (!dump_skip(cprm, skip))
 177                 goto Eio;
 178 out:
 179         free_page((unsigned long)buf);
 180         return rc;
 181 Eio:
 182         free_page((unsigned long)buf);
 183         return -EIO;
 184 }
 185
 186 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)
 187 {
 188         struct spu_context *ctx;
 189         int fd, j, rc;
 190
 191         fd = 0;
 192         while ((ctx = coredump_next_context(&fd)) != NULL) {
 193                 rc = spu_acquire_saved(ctx);
 194                 if (rc)
 195                         return rc;
 196
 197                 for (j = 0; spufs_coredump_read[j].name != NULL; j++) {
 198                         rc = spufs_arch_write_note(ctx, j, cprm, fd);
 199                         if (rc) {
 200                                 spu_release_saved(ctx);
 201                                 return rc;
 202                         }
 203                 }
 204
 205                 spu_release_saved(ctx);
 206
 207                 /* start searching the next fd next time */
 208                 fd++;
 209         }
 210
 211         return 0;
 212 }