release/src-rt-6.x/linux/linux-2.6/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/fs.h>
  26 #include <linux/list.h>
  27 #include <linux/module.h>
  28 #include <linux/syscalls.h>
  29
  30 #include <asm/uaccess.h>
  31
  32 #include "spufs.h"
  33
  34 struct spufs_ctx_info {
  35         struct list_head list;
  36         int dfd;
  37         int memsize; /* in bytes */
  38         struct spu_context *ctx;
  39 };
  40
  41 static LIST_HEAD(ctx_info_list);
  42
  43 static ssize_t do_coredump_read(int num, struct spu_context *ctx, void __user *buffer,
  44                                 size_t size, loff_t *off)
  45 {
  46         u64 data;
  47         int ret;
  48
  49         if (spufs_coredump_read[num].read)
  50                 return spufs_coredump_read[num].read(ctx, buffer, size, off);
  51
  52         data = spufs_coredump_read[num].get(ctx);
  53         ret = copy_to_user(buffer, &data, 8);
  54         return ret ? -EFAULT : 8;
  55 }
  56
  57 /*
  58  * These are the only things you should do on a core-file: use only these
  59  * functions to write out all the necessary info.
  60  */
  61 static int spufs_dump_write(struct file *file, const void *addr, int nr)
  62 {
  63         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
  64 }
  65
  66 static int spufs_dump_seek(struct file *file, loff_t off)
  67 {
  68         if (file->f_op->llseek) {
  69                 if (file->f_op->llseek(file, off, 0) != off)
  70                         return 0;
  71         } else
  72                 file->f_pos = off;
  73         return 1;
  74 }
  75
  76 static void spufs_fill_memsize(struct spufs_ctx_info *ctx_info)
  77 {
  78         struct spu_context *ctx;
  79         unsigned long long lslr;
  80
  81         ctx = ctx_info->ctx;
  82         lslr = ctx->csa.priv2.spu_lslr_RW;
  83         ctx_info->memsize = lslr + 1;
  84 }
  85
  86 static int spufs_ctx_note_size(struct spufs_ctx_info *ctx_info)
  87 {
  88         int dfd, memsize, i, sz, total = 0;
  89         char *name;
  90         char fullname[80];
  91
  92         dfd = ctx_info->dfd;
  93         memsize = ctx_info->memsize;
  94
  95         for (i = 0; spufs_coredump_read[i].name; i++) {
  96                 name = spufs_coredump_read[i].name;
  97                 sz = spufs_coredump_read[i].size;
  98
  99                 sprintf(fullname, "SPU/%d/%s", dfd, name);
 100
 101                 total += sizeof(struct elf_note);
 102                 total += roundup(strlen(fullname) + 1, 4);
 103                 if (!strcmp(name, "mem"))
 104                         total += roundup(memsize, 4);
 105                 else
 106                         total += roundup(sz, 4);
 107         }
 108
 109         return total;
 110 }
 111
 112 static int spufs_add_one_context(struct file *file, int dfd)
 113 {
 114         struct spu_context *ctx;
 115         struct spufs_ctx_info *ctx_info;
 116         int size;
 117
 118         ctx = SPUFS_I(file->f_dentry->d_inode)->i_ctx;
 119         if (ctx->flags & SPU_CREATE_NOSCHED)
 120                 return 0;
 121
 122         ctx_info = kzalloc(sizeof(*ctx_info), GFP_KERNEL);
 123         if (unlikely(!ctx_info))
 124                 return -ENOMEM;
 125
 126         ctx_info->dfd = dfd;
 127         ctx_info->ctx = ctx;
 128
 129         spufs_fill_memsize(ctx_info);
 130
 131         size = spufs_ctx_note_size(ctx_info);
 132         list_add(&ctx_info->list, &ctx_info_list);
 133         return size;
 134 }
 135
 136 /*
 137  * The additional architecture-specific notes for Cell are various
 138  * context files in the spu context.
 139  *
 140  * This function iterates over all open file descriptors and sees
 141  * if they are a directory in spufs.  In that case we use spufs
 142  * internal functionality to dump them without needing to actually
 143  * open the files.
 144  */
 145 static int spufs_arch_notes_size(void)
 146 {
 147         struct fdtable *fdt = files_fdtable(current->files);
 148         int size = 0, fd;
 149
 150         for (fd = 0; fd < fdt->max_fds; fd++) {
 151                 if (FD_ISSET(fd, fdt->open_fds)) {
 152                         struct file *file = fcheck(fd);
 153
 154                         if (file && file->f_op == &spufs_context_fops) {
 155                                 int rval = spufs_add_one_context(file, fd);
 156                                 if (rval < 0)
 157                                         break;
 158                                 size += rval;
 159                         }
 160                 }
 161         }
 162
 163         return size;
 164 }
 165
 166 static void spufs_arch_write_note(struct spufs_ctx_info *ctx_info, int i,
 167                                 struct file *file)
 168 {
 169         struct spu_context *ctx;
 170         loff_t pos = 0;
 171         int sz, dfd, rc, total = 0;
 172         const int bufsz = PAGE_SIZE;
 173         char *name;
 174         char fullname[80], *buf;
 175         struct elf_note en;
 176
 177         buf = (void *)get_zeroed_page(GFP_KERNEL);
 178         if (!buf)
 179                 return;
 180
 181         dfd = ctx_info->dfd;
 182         name = spufs_coredump_read[i].name;
 183
 184         if (!strcmp(name, "mem"))
 185                 sz = ctx_info->memsize;
 186         else
 187                 sz = spufs_coredump_read[i].size;
 188
 189         ctx = ctx_info->ctx;
 190         if (!ctx)
 191                 goto out;
 192
 193         sprintf(fullname, "SPU/%d/%s", dfd, name);
 194         en.n_namesz = strlen(fullname) + 1;
 195         en.n_descsz = sz;
 196         en.n_type = NT_SPU;
 197
 198         if (!spufs_dump_write(file, &en, sizeof(en)))
 199                 goto out;
 200         if (!spufs_dump_write(file, fullname, en.n_namesz))
 201                 goto out;
 202         if (!spufs_dump_seek(file, roundup((unsigned long)file->f_pos, 4)))
 203                 goto out;
 204
 205         do {
 206                 rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
 207                 if (rc > 0) {
 208                         if (!spufs_dump_write(file, buf, rc))
 209                                 goto out;
 210                         total += rc;
 211                 }
 212         } while (rc == bufsz && total < sz);
 213
 214         spufs_dump_seek(file, roundup((unsigned long)file->f_pos
 215                                                 - total + sz, 4));
 216 out:
 217         free_page((unsigned long)buf);
 218 }
 219
 220 static void spufs_arch_write_notes(struct file *file)
 221 {
 222         int j;
 223         struct spufs_ctx_info *ctx_info, *next;
 224
 225         list_for_each_entry_safe(ctx_info, next, &ctx_info_list, list) {
 226                 spu_acquire_saved(ctx_info->ctx);
 227                 for (j = 0; j < spufs_coredump_num_notes; j++)
 228                         spufs_arch_write_note(ctx_info, j, file);
 229                 spu_release(ctx_info->ctx);
 230                 list_del(&ctx_info->list);
 231                 kfree(ctx_info);
 232         }
 233 }
 234
 235 struct spu_coredump_calls spufs_coredump_calls = {
 236         .arch_notes_size = spufs_arch_notes_size,
 237         .arch_write_notes = spufs_arch_write_notes,
 238         .owner = THIS_MODULE,
 239 };