LXR linux/arch/powerpc/platforms/cell/spufs/coredump.c

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