[POWERPC] spufs: Handle errors in SPU coredump code, and support coredump to a pipe

Rework spufs_coredump_extra_notes_write() to check for and return errors.

If we're coredumping to a pipe we can't trust file->f_pos, we need to
maintain the foffset value passed to us. The cleanest way to do this is
to have the low level write routine increment foffset when we've
successfully written.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/cell/spu_syscalls.c b/arch/powerpc/platforms/cell/spu_syscalls.c
index b0117a7c6100f7ebc86cbc97181bb0c3a755db2b..a9438b719fe8ba38e53f48f4e2106e1e81746cc0 100644 (file)
--- a/arch/powerpc/platforms/cell/spu_syscalls.c
+++ b/arch/powerpc/platforms/cell/spu_syscalls.c
@@ -132,19 +132,17 @@ int elf_coredump_extra_notes_size(void)
 int elf_coredump_extra_notes_write(struct file *file, loff_t *foffset)
 {
        struct spufs_calls *calls;
+       int ret;
 
        calls = spufs_calls_get();
        if (!calls)
                return 0;
 
-       calls->coredump_extra_notes_write(file);
+       ret = calls->coredump_extra_notes_write(file, foffset);
 
        spufs_calls_put(calls);
 
-       /* Fudge foffset for now */
-       *foffset = file->f_pos;
-
-       return 0;
+       return ret;
 }
 
 int register_spu_syscalls(struct spufs_calls *calls)

diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
index 6c20e44dba630aef7fa457680f943efeee547c81..6b8aef6d7e688217a292cc3ee7c5d2d5d89b0e18 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/coredump.c
+++ b/arch/powerpc/platforms/cell/spufs/coredump.c
@@ -51,19 +51,34 @@ static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
  * These are the only things you should do on a core-file: use only these
  * functions to write out all the necessary info.
  */
-static int spufs_dump_write(struct file *file, const void *addr, int nr)
+static int spufs_dump_write(struct file *file, const void *addr, int nr, loff_t *foffset)
 {
-       return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+       ssize_t written;
+
+       written = file->f_op->write(file, addr, nr, &file->f_pos);
+       *foffset += written;
+
+       if (written != nr)
+               return -EIO;
+
+       return 0;
 }
 
-static int spufs_dump_seek(struct file *file, loff_t off)
+static int spufs_dump_align(struct file *file, char *buf, loff_t new_off,
+                           loff_t *foffset)
 {
-       if (file->f_op->llseek) {
-               if (file->f_op->llseek(file, off, 0) != off)
-                       return 0;
-       } else
-               file->f_pos = off;
-       return 1;
+       int rc, size;
+
+       size = min((loff_t)PAGE_SIZE, new_off - *foffset);
+       memset(buf, 0, size);
+
+       rc = 0;
+       while (rc == 0 && new_off > *foffset) {
+               size = min((loff_t)PAGE_SIZE, new_off - *foffset);
+               rc = spufs_dump_write(file, buf, size, foffset);
+       }
+
+       return rc;
 }
 
 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
@@ -141,11 +156,11 @@ int spufs_coredump_extra_notes_size(void)
        return size;
 }
 
-static void spufs_arch_write_note(struct spu_context *ctx, int i,
-                               struct file *file, int dfd)
+static int spufs_arch_write_note(struct spu_context *ctx, int i,
+                                 struct file *file, int dfd, loff_t *foffset)
 {
        loff_t pos = 0;
-       int sz, rc, total = 0;
+       int sz, rc, nread, total = 0;
        const int bufsz = PAGE_SIZE;
        char *name;
        char fullname[80], *buf;
@@ -153,7 +168,7 @@ static void spufs_arch_write_note(struct spu_context *ctx, int i,
 
        buf = (void *)get_zeroed_page(GFP_KERNEL);
        if (!buf)
-               return;
+               return -ENOMEM;
 
        name = spufs_coredump_read[i].name;
        sz = spufs_coredump_read[i].size;
@@ -163,40 +178,60 @@ static void spufs_arch_write_note(struct spu_context *ctx, int i,
        en.n_descsz = sz;
        en.n_type = NT_SPU;
 
-       if (!spufs_dump_write(file, &en, sizeof(en)))
+       rc = spufs_dump_write(file, &en, sizeof(en), foffset);
+       if (rc)
                goto out;
-       if (!spufs_dump_write(file, fullname, en.n_namesz))
+
+       rc = spufs_dump_write(file, fullname, en.n_namesz, foffset);
+       if (rc)
                goto out;
-       if (!spufs_dump_seek(file, roundup((unsigned long)file->f_pos, 4)))
+
+       rc = spufs_dump_align(file, buf, roundup(*foffset, 4), foffset);
+       if (rc)
                goto out;
 
        do {
-               rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
-               if (rc > 0) {
-                       if (!spufs_dump_write(file, buf, rc))
+               nread = do_coredump_read(i, ctx, buf, bufsz, &pos);
+               if (nread > 0) {
+                       rc = spufs_dump_write(file, buf, nread, foffset);
+                       if (rc)
                                goto out;
-                       total += rc;
+                       total += nread;
                }
-       } while (rc == bufsz && total < sz);
+       } while (nread == bufsz && total < sz);
+
+       if (nread < 0) {
+               rc = nread;
+               goto out;
+       }
+
+       rc = spufs_dump_align(file, buf, roundup(*foffset - total + sz, 4),
+                             foffset);
 
-       spufs_dump_seek(file, roundup((unsigned long)file->f_pos
-                                               - total + sz, 4));
 out:
        free_page((unsigned long)buf);
+       return rc;
 }
 
-void spufs_coredump_extra_notes_write(struct file *file)
+int spufs_coredump_extra_notes_write(struct file *file, loff_t *foffset)
 {
        struct spu_context *ctx;
-       int fd, j;
+       int fd, j, rc;
 
        fd = 0;
        while ((ctx = coredump_next_context(&fd)) != NULL) {
                spu_acquire_saved(ctx);
 
-               for (j = 0; spufs_coredump_read[j].name != NULL; j++)
-                       spufs_arch_write_note(ctx, j, file, fd);
+               for (j = 0; spufs_coredump_read[j].name != NULL; j++) {
+                       rc = spufs_arch_write_note(ctx, j, file, fd, foffset);
+                       if (rc) {
+                               spu_release_saved(ctx);
+                               return rc;
+                       }
+               }
 
                spu_release_saved(ctx);
        }
+
+       return 0;
 }

diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index c7b4e035de484ea9f0396c353f9cd623c606cf05..ca47b991bda5e3dd639d8b40b5dccf47d4a1557e 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -206,7 +206,7 @@ long spufs_create(struct nameidata *nd, unsigned int flags,
                        mode_t mode, struct file *filp);
 /* ELF coredump callbacks for writing SPU ELF notes */
 extern int spufs_coredump_extra_notes_size(void);
-extern void spufs_coredump_extra_notes_write(struct file *file);
+extern int spufs_coredump_extra_notes_write(struct file *file, loff_t *foffset);
 
 extern const struct file_operations spufs_context_fops;
 

diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index f1b10a187987dac02324b0364f5f5fd36b87138b..b1accce77bb5a84a52a5f3b165bff1350137770e 100644 (file)
--- a/include/asm-powerpc/spu.h
+++ b/include/asm-powerpc/spu.h
@@ -245,7 +245,7 @@ struct spufs_calls {
        long (*spu_run)(struct file *filp, __u32 __user *unpc,
                                                __u32 __user *ustatus);
        int (*coredump_extra_notes_size)(void);
-       void (*coredump_extra_notes_write)(struct file *file);
+       int (*coredump_extra_notes_write)(struct file *file, loff_t *foffset);
        struct module *owner;
 };