[PATCH 13/15] Handle errors in SPU coredump code, and support coredump to a pipe
Michael Ellerman
michael at ellerman.id.au
Wed Sep 12 17:43:50 EST 2007
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 at ellerman.id.au>
---
arch/powerpc/platforms/cell/spu_syscalls.c | 8 +--
arch/powerpc/platforms/cell/spufs/coredump.c | 89 ++++++++++++++++++--------
arch/powerpc/platforms/cell/spufs/spufs.h | 2 +-
include/asm-powerpc/spu.h | 2 +-
4 files changed, 67 insertions(+), 34 deletions(-)
diff --git a/arch/powerpc/platforms/cell/spu_syscalls.c b/arch/powerpc/platforms/cell/spu_syscalls.c
index d9b2fd2..0b69107 100644
--- a/arch/powerpc/platforms/cell/spu_syscalls.c
+++ b/arch/powerpc/platforms/cell/spu_syscalls.c
@@ -129,19 +129,17 @@ 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 7395350..c3b5cd5 100644
--- 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; j < spufs_coredump_num_notes; j++)
- spufs_arch_write_note(ctx, j, file, fd);
+ for (j = 0; j < spufs_coredump_num_notes; 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 c7b4e03..ca47b99 100644
--- 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 10c40cd..eed63dd 100644
--- 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;
};
--
1.5.1.3.g7a33b
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