1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SPU core dump code
4 *
5 * (C) Copyright 2006 IBM Corp.
6 *
7 * Author: Dwayne Grant McConnell <decimal@us.ibm.com>
8 */
9
10 #include <linux/elf.h>
11 #include <linux/file.h>
12 #include <linux/fdtable.h>
13 #include <linux/fs.h>
14 #include <linux/gfp.h>
15 #include <linux/list.h>
16 #include <linux/syscalls.h>
17 #include <linux/coredump.h>
18 #include <linux/binfmts.h>
19
20 #include <linux/uaccess.h>
21
22 #include "spufs.h"
23
do_coredump_read(int num,struct spu_context * ctx,void * buffer,size_t size,loff_t * off)24 static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
25 size_t size, loff_t *off)
26 {
27 u64 data;
28 int ret;
29
30 if (spufs_coredump_read[num].read)
31 return spufs_coredump_read[num].read(ctx, buffer, size, off);
32
33 data = spufs_coredump_read[num].get(ctx);
34 ret = snprintf(buffer, size, "0x%.16llx", data);
35 if (ret >= size)
36 return size;
37 return ++ret; /* count trailing NULL */
38 }
39
spufs_ctx_note_size(struct spu_context * ctx,int dfd)40 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
41 {
42 int i, sz, total = 0;
43 char *name;
44 char fullname[80];
45
46 for (i = 0; spufs_coredump_read[i].name != NULL; i++) {
47 name = spufs_coredump_read[i].name;
48 sz = spufs_coredump_read[i].size;
49
50 sprintf(fullname, "SPU/%d/%s", dfd, name);
51
52 total += sizeof(struct elf_note);
53 total += roundup(strlen(fullname) + 1, 4);
54 total += roundup(sz, 4);
55 }
56
57 return total;
58 }
59
match_context(const void * v,struct file * file,unsigned fd)60 static int match_context(const void *v, struct file *file, unsigned fd)
61 {
62 struct spu_context *ctx;
63 if (file->f_op != &spufs_context_fops)
64 return 0;
65 ctx = SPUFS_I(file_inode(file))->i_ctx;
66 if (ctx->flags & SPU_CREATE_NOSCHED)
67 return 0;
68 return fd + 1;
69 }
70
71 /*
72 * The additional architecture-specific notes for Cell are various
73 * context files in the spu context.
74 *
75 * This function iterates over all open file descriptors and sees
76 * if they are a directory in spufs. In that case we use spufs
77 * internal functionality to dump them without needing to actually
78 * open the files.
79 */
80 /*
81 * descriptor table is not shared, so files can't change or go away.
82 */
coredump_next_context(int * fd)83 static struct spu_context *coredump_next_context(int *fd)
84 {
85 struct file *file;
86 int n = iterate_fd(current->files, *fd, match_context, NULL);
87 if (!n)
88 return NULL;
89 *fd = n - 1;
90 file = fcheck(*fd);
91 return SPUFS_I(file_inode(file))->i_ctx;
92 }
93
spufs_coredump_extra_notes_size(void)94 int spufs_coredump_extra_notes_size(void)
95 {
96 struct spu_context *ctx;
97 int size = 0, rc, fd;
98
99 fd = 0;
100 while ((ctx = coredump_next_context(&fd)) != NULL) {
101 rc = spu_acquire_saved(ctx);
102 if (rc)
103 break;
104 rc = spufs_ctx_note_size(ctx, fd);
105 spu_release_saved(ctx);
106 if (rc < 0)
107 break;
108
109 size += rc;
110
111 /* start searching the next fd next time */
112 fd++;
113 }
114
115 return size;
116 }
117
spufs_arch_write_note(struct spu_context * ctx,int i,struct coredump_params * cprm,int dfd)118 static int spufs_arch_write_note(struct spu_context *ctx, int i,
119 struct coredump_params *cprm, int dfd)
120 {
121 loff_t pos = 0;
122 int sz, rc, total = 0;
123 const int bufsz = PAGE_SIZE;
124 char *name;
125 char fullname[80], *buf;
126 struct elf_note en;
127 size_t skip;
128
129 buf = (void *)get_zeroed_page(GFP_KERNEL);
130 if (!buf)
131 return -ENOMEM;
132
133 name = spufs_coredump_read[i].name;
134 sz = spufs_coredump_read[i].size;
135
136 sprintf(fullname, "SPU/%d/%s", dfd, name);
137 en.n_namesz = strlen(fullname) + 1;
138 en.n_descsz = sz;
139 en.n_type = NT_SPU;
140
141 if (!dump_emit(cprm, &en, sizeof(en)))
142 goto Eio;
143
144 if (!dump_emit(cprm, fullname, en.n_namesz))
145 goto Eio;
146
147 if (!dump_align(cprm, 4))
148 goto Eio;
149
150 do {
151 rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
152 if (rc > 0) {
153 if (!dump_emit(cprm, buf, rc))
154 goto Eio;
155 total += rc;
156 }
157 } while (rc == bufsz && total < sz);
158
159 if (rc < 0)
160 goto out;
161
162 skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;
163 if (!dump_skip(cprm, skip))
164 goto Eio;
165
166 rc = 0;
167 out:
168 free_page((unsigned long)buf);
169 return rc;
170 Eio:
171 free_page((unsigned long)buf);
172 return -EIO;
173 }
174
spufs_coredump_extra_notes_write(struct coredump_params * cprm)175 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)
176 {
177 struct spu_context *ctx;
178 int fd, j, rc;
179
180 fd = 0;
181 while ((ctx = coredump_next_context(&fd)) != NULL) {
182 rc = spu_acquire_saved(ctx);
183 if (rc)
184 return rc;
185
186 for (j = 0; spufs_coredump_read[j].name != NULL; j++) {
187 rc = spufs_arch_write_note(ctx, j, cprm, fd);
188 if (rc) {
189 spu_release_saved(ctx);
190 return rc;
191 }
192 }
193
194 spu_release_saved(ctx);
195
196 /* start searching the next fd next time */
197 fd++;
198 }
199
200 return 0;
201 }
202
