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
37static 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
53static 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
73static 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 */
96static 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
107int 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
131static 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;
177out:
178	free_page((unsigned long)buf);
179	return rc;
180Eio:
181	free_page((unsigned long)buf);
182	return -EIO;
183}
184
185int 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