root/arch/powerpc/platforms/cell/spufs/coredump.c

DEFINITIONS

1. do_coredump_read
2. spufs_ctx_note_size
3. match_context
4. coredump_next_context
5. spufs_coredump_extra_notes_size
6. spufs_arch_write_note
7. spufs_coredump_extra_notes_write

   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 
  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 
  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 
  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  */
  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 
  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 
 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 
 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 }