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 24static 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 44static 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 */ 67static 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 rcu_read_lock(); 77 file = lookup_fdget_rcu(*fd); 78 rcu_read_unlock(); 79 if (file) { 80 ctx = SPUFS_I(file_inode(file))->i_ctx; 81 get_spu_context(ctx); 82 fput(file); 83 } 84 85 return ctx; 86} 87 88int spufs_coredump_extra_notes_size(void) 89{ 90 struct spu_context *ctx; 91 int size = 0, rc, fd; 92 93 fd = 0; 94 while ((ctx = coredump_next_context(&fd)) != NULL) { 95 rc = spu_acquire_saved(ctx); 96 if (rc) { 97 put_spu_context(ctx); 98 break; 99 } 100 101 rc = spufs_ctx_note_size(ctx, fd); 102 spu_release_saved(ctx); 103 if (rc < 0) { 104 put_spu_context(ctx); 105 break; 106 } 107 108 size += rc; 109 110 /* start searching the next fd next time */ 111 fd++; 112 put_spu_context(ctx); 113 } 114 115 return size; 116} 117 118static int spufs_arch_write_note(struct spu_context *ctx, int i, 119 struct coredump_params *cprm, int dfd) 120{ 121 size_t sz = spufs_coredump_read[i].size; 122 char fullname[80]; 123 struct elf_note en; 124 int ret; 125 126 sprintf(fullname, "SPU/%d/%s", dfd, spufs_coredump_read[i].name); 127 en.n_namesz = strlen(fullname) + 1; 128 en.n_descsz = sz; 129 en.n_type = NT_SPU; 130 131 if (!dump_emit(cprm, &en, sizeof(en))) 132 return -EIO; 133 if (!dump_emit(cprm, fullname, en.n_namesz)) 134 return -EIO; 135 if (!dump_align(cprm, 4)) 136 return -EIO; 137 138 if (spufs_coredump_read[i].dump) { 139 ret = spufs_coredump_read[i].dump(ctx, cprm); 140 if (ret < 0) 141 return ret; 142 } else { 143 char buf[32]; 144 145 ret = snprintf(buf, sizeof(buf), "0x%.16llx", 146 spufs_coredump_read[i].get(ctx)); 147 if (ret >= sizeof(buf)) 148 return sizeof(buf); 149 150 /* count trailing the NULL: */ 151 if (!dump_emit(cprm, buf, ret + 1)) 152 return -EIO; 153 } 154 155 dump_skip_to(cprm, roundup(cprm->pos - ret + sz, 4)); 156 return 0; 157} 158 159int spufs_coredump_extra_notes_write(struct coredump_params *cprm) 160{ 161 struct spu_context *ctx; 162 int fd, j, rc; 163 164 fd = 0; 165 while ((ctx = coredump_next_context(&fd)) != NULL) { 166 rc = spu_acquire_saved(ctx); 167 if (rc) 168 return rc; 169 170 for (j = 0; spufs_coredump_read[j].name != NULL; j++) { 171 rc = spufs_arch_write_note(ctx, j, cprm, fd); 172 if (rc) { 173 spu_release_saved(ctx); 174 return rc; 175 } 176 } 177 178 spu_release_saved(ctx); 179 180 /* start searching the next fd next time */ 181 fd++; 182 } 183 184 return 0; 185} 186