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 <[email protected]>
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
spufs_ctx_note_size(struct spu_context * ctx,int dfd)24 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
25 {
26 int i, sz, total = 0;
27 char *name;
28 char fullname[80];
29
30 for (i = 0; spufs_coredump_read[i].name != NULL; i++) {
31 name = spufs_coredump_read[i].name;
32 sz = spufs_coredump_read[i].size;
33
34 sprintf(fullname, "SPU/%d/%s", dfd, name);
35
36 total += sizeof(struct elf_note);
37 total += roundup(strlen(fullname) + 1, 4);
38 total += roundup(sz, 4);
39 }
40
41 return total;
42 }
43
match_context(const void * v,struct file * file,unsigned fd)44 static int match_context(const void *v, struct file *file, unsigned fd)
45 {
46 struct spu_context *ctx;
47 if (file->f_op != &spufs_context_fops)
48 return 0;
49 ctx = SPUFS_I(file_inode(file))->i_ctx;
50 if (ctx->flags & SPU_CREATE_NOSCHED)
51 return 0;
52 return fd + 1;
53 }
54
55 /*
56 * The additional architecture-specific notes for Cell are various
57 * context files in the spu context.
58 *
59 * This function iterates over all open file descriptors and sees
60 * if they are a directory in spufs. In that case we use spufs
61 * internal functionality to dump them without needing to actually
62 * open the files.
63 */
64 /*
65 * descriptor table is not shared, so files can't change or go away.
66 */
coredump_next_context(int * fd)67 static struct spu_context *coredump_next_context(int *fd)
68 {
69 struct spu_context *ctx = NULL;
70 struct file *file;
71 int n = iterate_fd(current->files, *fd, match_context, NULL);
72 if (!n)
73 return NULL;
74 *fd = n - 1;
75
76 file = fget_raw(*fd);
77 if (file) {
78 ctx = SPUFS_I(file_inode(file))->i_ctx;
79 get_spu_context(ctx);
80 fput(file);
81 }
82
83 return ctx;
84 }
85
spufs_coredump_extra_notes_size(void)86 int spufs_coredump_extra_notes_size(void)
87 {
88 struct spu_context *ctx;
89 int size = 0, rc, fd;
90
91 fd = 0;
92 while ((ctx = coredump_next_context(&fd)) != NULL) {
93 rc = spu_acquire_saved(ctx);
94 if (rc) {
95 put_spu_context(ctx);
96 break;
97 }
98
99 rc = spufs_ctx_note_size(ctx, fd);
100 spu_release_saved(ctx);
101 if (rc < 0) {
102 put_spu_context(ctx);
103 break;
104 }
105
106 size += rc;
107
108 /* start searching the next fd next time */
109 fd++;
110 put_spu_context(ctx);
111 }
112
113 return size;
114 }
115
spufs_arch_write_note(struct spu_context * ctx,int i,struct coredump_params * cprm,int dfd)116 static int spufs_arch_write_note(struct spu_context *ctx, int i,
117 struct coredump_params *cprm, int dfd)
118 {
119 size_t sz = spufs_coredump_read[i].size;
120 char fullname[80];
121 struct elf_note en;
122 int ret;
123
124 sprintf(fullname, "SPU/%d/%s", dfd, spufs_coredump_read[i].name);
125 en.n_namesz = strlen(fullname) + 1;
126 en.n_descsz = sz;
127 en.n_type = NT_SPU;
128
129 if (!dump_emit(cprm, &en, sizeof(en)))
130 return -EIO;
131 if (!dump_emit(cprm, fullname, en.n_namesz))
132 return -EIO;
133 if (!dump_align(cprm, 4))
134 return -EIO;
135
136 if (spufs_coredump_read[i].dump) {
137 ret = spufs_coredump_read[i].dump(ctx, cprm);
138 if (ret < 0)
139 return ret;
140 } else {
141 char buf[32];
142
143 ret = snprintf(buf, sizeof(buf), "0x%.16llx",
144 spufs_coredump_read[i].get(ctx));
145 if (ret >= sizeof(buf))
146 return sizeof(buf);
147
148 /* count trailing the NULL: */
149 if (!dump_emit(cprm, buf, ret + 1))
150 return -EIO;
151 }
152
153 dump_skip_to(cprm, roundup(cprm->pos - ret + sz, 4));
154 return 0;
155 }
156
spufs_coredump_extra_notes_write(struct coredump_params * cprm)157 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)
158 {
159 struct spu_context *ctx;
160 int fd, j, rc;
161
162 fd = 0;
163 while ((ctx = coredump_next_context(&fd)) != NULL) {
164 rc = spu_acquire_saved(ctx);
165 if (rc)
166 return rc;
167
168 for (j = 0; spufs_coredump_read[j].name != NULL; j++) {
169 rc = spufs_arch_write_note(ctx, j, cprm, fd);
170 if (rc) {
171 spu_release_saved(ctx);
172 return rc;
173 }
174 }
175
176 spu_release_saved(ctx);
177
178 /* start searching the next fd next time */
179 fd++;
180 }
181
182 return 0;
183 }
184