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
do_coredump_read(int num,struct spu_context * ctx,void * buffer,size_t size,loff_t * off)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
spufs_ctx_note_size(struct spu_context * ctx,int dfd)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
match_context(const void * v,struct file * file,unsigned fd)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 */
coredump_next_context(int * fd)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
spufs_coredump_extra_notes_size(void)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
spufs_arch_write_note(struct spu_context * ctx,int i,struct coredump_params * cprm,int dfd)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
141 buf = (void *)get_zeroed_page(GFP_KERNEL);
142 if (!buf)
143 return -ENOMEM;
144
145 name = spufs_coredump_read[i].name;
146 sz = spufs_coredump_read[i].size;
147
148 sprintf(fullname, "SPU/%d/%s", dfd, name);
149 en.n_namesz = strlen(fullname) + 1;
150 en.n_descsz = sz;
151 en.n_type = NT_SPU;
152
153 if (!dump_emit(cprm, &en, sizeof(en)))
154 goto Eio;
155
156 if (!dump_emit(cprm, fullname, en.n_namesz))
157 goto Eio;
158
159 if (!dump_align(cprm, 4))
160 goto Eio;
161
162 do {
163 rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
164 if (rc > 0) {
165 if (!dump_emit(cprm, buf, rc))
166 goto Eio;
167 total += rc;
168 }
169 } while (rc == bufsz && total < sz);
170
171 if (rc < 0)
172 goto out;
173
174 if (!dump_skip(cprm,
175 roundup(cprm->written - total + sz, 4) - cprm->written))
176 goto Eio;
177 out:
178 free_page((unsigned long)buf);
179 return rc;
180 Eio:
181 free_page((unsigned long)buf);
182 return -EIO;
183 }
184
spufs_coredump_extra_notes_write(struct coredump_params * cprm)185 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)
186 {
187 struct spu_context *ctx;
188 int fd, j, rc;
189
190 fd = 0;
191 while ((ctx = coredump_next_context(&fd)) != NULL) {
192 rc = spu_acquire_saved(ctx);
193 if (rc)
194 return rc;
195
196 for (j = 0; spufs_coredump_read[j].name != NULL; j++) {
197 rc = spufs_arch_write_note(ctx, j, cprm, fd);
198 if (rc) {
199 spu_release_saved(ctx);
200 return rc;
201 }
202 }
203
204 spu_release_saved(ctx);
205
206 /* start searching the next fd next time */
207 fd++;
208 }
209
210 return 0;
211 }
212