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 <asm/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 } 213