powerpc/spufs: simplify spufs core dumping

Replace the coredump ->read method with a ->dump method that must call
dump_emit itself.  That way we avoid a buffer allocation an messing with
set_fs() to call into code that is intended to deal with user buffers.
For the ->get case we can now use a small on-stack buffer and avoid
memory allocations as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
index 8b3296b62f651fee604012652def96a7ecffd6e1..3b75e8f60609cbd0fd7cd2416c587c387ed57de7 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/coredump.c
+++ b/arch/powerpc/platforms/cell/spufs/coredump.c
@@ -21,22 +21,6 @@
 
 #include "spufs.h"
 
-static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
-                               size_t size, loff_t *off)
-{
-       u64 data;
-       int ret;
-
-       if (spufs_coredump_read[num].read)
-               return spufs_coredump_read[num].read(ctx, buffer, size, off);
-
-       data = spufs_coredump_read[num].get(ctx);
-       ret = snprintf(buffer, size, "0x%.16llx", data);
-       if (ret >= size)
-               return size;
-       return ++ret; /* count trailing NULL */
-}
-
 static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
 {
        int i, sz, total = 0;
@@ -118,58 +102,43 @@ int spufs_coredump_extra_notes_size(void)
 static int spufs_arch_write_note(struct spu_context *ctx, int i,
                                  struct coredump_params *cprm, int dfd)
 {
-       loff_t pos = 0;
-       int sz, rc, total = 0;
-       const int bufsz = PAGE_SIZE;
-       char *name;
-       char fullname[80], *buf;
+       size_t sz = spufs_coredump_read[i].size;
+       char fullname[80];
        struct elf_note en;
-       size_t skip;
-
-       buf = (void *)get_zeroed_page(GFP_KERNEL);
-       if (!buf)
-               return -ENOMEM;
+       size_t ret;
 
-       name = spufs_coredump_read[i].name;
-       sz = spufs_coredump_read[i].size;
-
-       sprintf(fullname, "SPU/%d/%s", dfd, name);
+       sprintf(fullname, "SPU/%d/%s", dfd, spufs_coredump_read[i].name);
        en.n_namesz = strlen(fullname) + 1;
        en.n_descsz = sz;
        en.n_type = NT_SPU;
 
        if (!dump_emit(cprm, &en, sizeof(en)))
-               goto Eio;
-
+               return -EIO;
        if (!dump_emit(cprm, fullname, en.n_namesz))
-               goto Eio;
-
+               return -EIO;
        if (!dump_align(cprm, 4))
-               goto Eio;
-
-       do {
-               rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
-               if (rc > 0) {
-                       if (!dump_emit(cprm, buf, rc))
-                               goto Eio;
-                       total += rc;
-               }
-       } while (rc == bufsz && total < sz);
-
-       if (rc < 0)
-               goto out;
-
-       skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;
-       if (!dump_skip(cprm, skip))
-               goto Eio;
-
-       rc = 0;
-out:
-       free_page((unsigned long)buf);
-       return rc;
-Eio:
-       free_page((unsigned long)buf);
-       return -EIO;
+               return -EIO;
+
+       if (spufs_coredump_read[i].dump) {
+               ret = spufs_coredump_read[i].dump(ctx, cprm);
+               if (ret < 0)
+                       return ret;
+       } else {
+               char buf[32];
+
+               ret = snprintf(buf, sizeof(buf), "0x%.16llx",
+                              spufs_coredump_read[i].get(ctx));
+               if (ret >= sizeof(buf))
+                       return sizeof(buf);
+
+               /* count trailing the NULL: */
+               if (!dump_emit(cprm, buf, ret + 1))
+                       return -EIO;
+       }
+
+       if (!dump_skip(cprm, roundup(cprm->pos - ret + sz, 4) - cprm->pos))
+               return -EIO;
+       return 0;
 }
 
 int spufs_coredump_extra_notes_write(struct coredump_params *cprm)

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index bd30b5e0c4c37de8dc42bea2fe388e1b188c907e..e44427c245850c716c75af0ffe2b8882549f67d6 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -9,6 +9,7 @@
 
 #undef DEBUG
 
+#include <linux/coredump.h>
 #include <linux/fs.h>
 #include <linux/ioctl.h>
 #include <linux/export.h>
@@ -129,6 +130,14 @@ out:
        return ret;
 }
 
+static ssize_t spufs_dump_emit(struct coredump_params *cprm, void *buf,
+               size_t size)
+{
+       if (!dump_emit(cprm, buf, size))
+               return -EIO;
+       return size;
+}
+
 #define DEFINE_SPUFS_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)     \
 static int __fops ## _open(struct inode *inode, struct file *file)     \
 {                                                                      \
@@ -172,12 +181,9 @@ spufs_mem_release(struct inode *inode, struct file *file)
 }
 
 static ssize_t
-__spufs_mem_read(struct spu_context *ctx, char __user *buffer,
-                       size_t size, loff_t *pos)
+spufs_mem_dump(struct spu_context *ctx, struct coredump_params *cprm)
 {
-       char *local_store = ctx->ops->get_ls(ctx);
-       return simple_read_from_buffer(buffer, size, pos, local_store,
-                                       LS_SIZE);
+       return spufs_dump_emit(cprm, ctx->ops->get_ls(ctx), LS_SIZE);
 }
 
 static ssize_t
@@ -190,7 +196,8 @@ spufs_mem_read(struct file *file, char __user *buffer,
        ret = spu_acquire(ctx);
        if (ret)
                return ret;
-       ret = __spufs_mem_read(ctx, buffer, size, pos);
+       ret = simple_read_from_buffer(buffer, size, pos, ctx->ops->get_ls(ctx),
+                                     LS_SIZE);
        spu_release(ctx);
 
        return ret;
@@ -459,12 +466,10 @@ spufs_regs_open(struct inode *inode, struct file *file)
 }
 
 static ssize_t
-__spufs_regs_read(struct spu_context *ctx, char __user *buffer,
-                       size_t size, loff_t *pos)
+spufs_regs_dump(struct spu_context *ctx, struct coredump_params *cprm)
 {
-       struct spu_lscsa *lscsa = ctx->csa.lscsa;
-       return simple_read_from_buffer(buffer, size, pos,
-                                     lscsa->gprs, sizeof lscsa->gprs);
+       return spufs_dump_emit(cprm, ctx->csa.lscsa->gprs,
+                              sizeof(ctx->csa.lscsa->gprs));
 }
 
 static ssize_t
@@ -482,7 +487,8 @@ spufs_regs_read(struct file *file, char __user *buffer,
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
-       ret = __spufs_regs_read(ctx, buffer, size, pos);
+       ret = simple_read_from_buffer(buffer, size, pos, ctx->csa.lscsa->gprs,
+                                     sizeof(ctx->csa.lscsa->gprs));
        spu_release_saved(ctx);
        return ret;
 }
@@ -517,12 +523,10 @@ static const struct file_operations spufs_regs_fops = {
 };
 
 static ssize_t
-__spufs_fpcr_read(struct spu_context *ctx, char __user * buffer,
-                       size_t size, loff_t * pos)
+spufs_fpcr_dump(struct spu_context *ctx, struct coredump_params *cprm)
 {
-       struct spu_lscsa *lscsa = ctx->csa.lscsa;
-       return simple_read_from_buffer(buffer, size, pos,
-                                     &lscsa->fpcr, sizeof(lscsa->fpcr));
+       return spufs_dump_emit(cprm, &ctx->csa.lscsa->fpcr,
+                              sizeof(ctx->csa.lscsa->fpcr));
 }
 
 static ssize_t
@@ -535,7 +539,8 @@ spufs_fpcr_read(struct file *file, char __user * buffer,
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
-       ret = __spufs_fpcr_read(ctx, buffer, size, pos);
+       ret = simple_read_from_buffer(buffer, size, pos, &ctx->csa.lscsa->fpcr,
+                                     sizeof(ctx->csa.lscsa->fpcr));
        spu_release_saved(ctx);
        return ret;
 }
@@ -953,28 +958,26 @@ spufs_signal1_release(struct inode *inode, struct file *file)
        return 0;
 }
 
-static ssize_t __spufs_signal1_read(struct spu_context *ctx, char __user *buf,
-                       size_t len, loff_t *pos)
+static ssize_t spufs_signal1_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
-       int ret = 0;
-       u32 data;
+       if (!ctx->csa.spu_chnlcnt_RW[3])
+               return 0;
+       return spufs_dump_emit(cprm, &ctx->csa.spu_chnldata_RW[3],
+                              sizeof(ctx->csa.spu_chnldata_RW[3]));
+}
 
-       if (len < 4)
+static ssize_t __spufs_signal1_read(struct spu_context *ctx, char __user *buf,
+                       size_t len)
+{
+       if (len < sizeof(ctx->csa.spu_chnldata_RW[3]))
                return -EINVAL;
-
-       if (ctx->csa.spu_chnlcnt_RW[3]) {
-               data = ctx->csa.spu_chnldata_RW[3];
-               ret = 4;
-       }
-
-       if (!ret)
-               goto out;
-
-       if (copy_to_user(buf, &data, 4))
+       if (!ctx->csa.spu_chnlcnt_RW[3])
+               return 0;
+       if (copy_to_user(buf, &ctx->csa.spu_chnldata_RW[3],
+                        sizeof(ctx->csa.spu_chnldata_RW[3])))
                return -EFAULT;
-
-out:
-       return ret;
+       return sizeof(ctx->csa.spu_chnldata_RW[3]);
 }
 
 static ssize_t spufs_signal1_read(struct file *file, char __user *buf,
@@ -986,7 +989,7 @@ static ssize_t spufs_signal1_read(struct file *file, char __user *buf,
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
-       ret = __spufs_signal1_read(ctx, buf, len, pos);
+       ret = __spufs_signal1_read(ctx, buf, len);
        spu_release_saved(ctx);
 
        return ret;
@@ -1090,28 +1093,26 @@ spufs_signal2_release(struct inode *inode, struct file *file)
        return 0;
 }
 
-static ssize_t __spufs_signal2_read(struct spu_context *ctx, char __user *buf,
-                       size_t len, loff_t *pos)
+static ssize_t spufs_signal2_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
-       int ret = 0;
-       u32 data;
+       if (!ctx->csa.spu_chnlcnt_RW[4])
+               return 0;
+       return spufs_dump_emit(cprm, &ctx->csa.spu_chnldata_RW[4],
+                              sizeof(ctx->csa.spu_chnldata_RW[4]));
+}
 
-       if (len < 4)
+static ssize_t __spufs_signal2_read(struct spu_context *ctx, char __user *buf,
+                       size_t len)
+{
+       if (len < sizeof(ctx->csa.spu_chnldata_RW[4]))
                return -EINVAL;
-
-       if (ctx->csa.spu_chnlcnt_RW[4]) {
-               data =  ctx->csa.spu_chnldata_RW[4];
-               ret = 4;
-       }
-
-       if (!ret)
-               goto out;
-
-       if (copy_to_user(buf, &data, 4))
+       if (!ctx->csa.spu_chnlcnt_RW[4])
+               return 0;
+       if (copy_to_user(buf, &ctx->csa.spu_chnldata_RW[4],
+                        sizeof(ctx->csa.spu_chnldata_RW[4])))
                return -EFAULT;
-
-out:
-       return ret;
+       return sizeof(ctx->csa.spu_chnldata_RW[4]);
 }
 
 static ssize_t spufs_signal2_read(struct file *file, char __user *buf,
@@ -1123,7 +1124,7 @@ static ssize_t spufs_signal2_read(struct file *file, char __user *buf,
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
-       ret = __spufs_signal2_read(ctx, buf, len, pos);
+       ret = __spufs_signal2_read(ctx, buf, len);
        spu_release_saved(ctx);
 
        return ret;
@@ -1947,18 +1948,13 @@ static const struct file_operations spufs_caps_fops = {
        .release        = single_release,
 };
 
-static ssize_t __spufs_mbox_info_read(struct spu_context *ctx,
-                       char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_mbox_info_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
-       u32 data;
-
-       /* EOF if there's no entry in the mbox */
        if (!(ctx->csa.prob.mb_stat_R & 0x0000ff))
                return 0;
-
-       data = ctx->csa.prob.pu_mb_R;
-
-       return simple_read_from_buffer(buf, len, pos, &data, sizeof data);
+       return spufs_dump_emit(cprm, &ctx->csa.prob.pu_mb_R,
+                              sizeof(ctx->csa.prob.pu_mb_R));
 }
 
 static ssize_t spufs_mbox_info_read(struct file *file, char __user *buf,
@@ -1990,18 +1986,13 @@ static const struct file_operations spufs_mbox_info_fops = {
        .llseek  = generic_file_llseek,
 };
 
-static ssize_t __spufs_ibox_info_read(struct spu_context *ctx,
-                               char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_ibox_info_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
-       u32 data;
-
-       /* EOF if there's no entry in the ibox */
        if (!(ctx->csa.prob.mb_stat_R & 0xff0000))
                return 0;
-
-       data = ctx->csa.priv2.puint_mb_R;
-
-       return simple_read_from_buffer(buf, len, pos, &data, sizeof data);
+       return spufs_dump_emit(cprm, &ctx->csa.priv2.puint_mb_R,
+                              sizeof(ctx->csa.priv2.puint_mb_R));
 }
 
 static ssize_t spufs_ibox_info_read(struct file *file, char __user *buf,
@@ -2038,21 +2029,11 @@ static size_t spufs_wbox_info_cnt(struct spu_context *ctx)
        return (4 - ((ctx->csa.prob.mb_stat_R & 0x00ff00) >> 8)) * sizeof(u32);
 }
 
-static ssize_t __spufs_wbox_info_read(struct spu_context *ctx,
-                       char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_wbox_info_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
-       int i, cnt;
-       u32 data[4];
-       u32 wbox_stat;
-
-       wbox_stat = ctx->csa.prob.mb_stat_R;
-       cnt = spufs_wbox_info_cnt(ctx);
-       for (i = 0; i < cnt; i++) {
-               data[i] = ctx->csa.spu_mailbox_data[i];
-       }
-
-       return simple_read_from_buffer(buf, len, pos, &data,
-                               cnt * sizeof(u32));
+       return spufs_dump_emit(cprm, &ctx->csa.spu_mailbox_data,
+                       spufs_wbox_info_cnt(ctx));
 }
 
 static ssize_t spufs_wbox_info_read(struct file *file, char __user *buf,
@@ -2102,15 +2083,13 @@ static void spufs_get_dma_info(struct spu_context *ctx,
        }
 }
 
-static ssize_t __spufs_dma_info_read(struct spu_context *ctx,
-                       char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_dma_info_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
        struct spu_dma_info info;
 
        spufs_get_dma_info(ctx, &info);
-
-       return simple_read_from_buffer(buf, len, pos, &info,
-                               sizeof info);
+       return spufs_dump_emit(cprm, &info, sizeof(info));
 }
 
 static ssize_t spufs_dma_info_read(struct file *file, char __user *buf,
@@ -2158,22 +2137,13 @@ static void spufs_get_proxydma_info(struct spu_context *ctx,
        }
 }
 
-static ssize_t __spufs_proxydma_info_read(struct spu_context *ctx,
-                       char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_proxydma_info_dump(struct spu_context *ctx,
+               struct coredump_params *cprm)
 {
        struct spu_proxydma_info info;
-       int ret = sizeof info;
-
-       if (len < ret)
-               return -EINVAL;
-
-       if (!access_ok(buf, len))
-               return -EFAULT;
 
        spufs_get_proxydma_info(ctx, &info);
-
-       return simple_read_from_buffer(buf, len, pos, &info,
-                               sizeof info);
+       return spufs_dump_emit(cprm, &info, sizeof(info));
 }
 
 static ssize_t spufs_proxydma_info_read(struct file *file, char __user *buf,
@@ -2183,6 +2153,9 @@ static ssize_t spufs_proxydma_info_read(struct file *file, char __user *buf,
        struct spu_proxydma_info info;
        int ret;
 
+       if (len < sizeof(info))
+               return -EINVAL;
+
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
@@ -2636,23 +2609,23 @@ const struct spufs_tree_descr spufs_dir_debug_contents[] = {
 };
 
 const struct spufs_coredump_reader spufs_coredump_read[] = {
-       { "regs", __spufs_regs_read, NULL, sizeof(struct spu_reg128[128])},
-       { "fpcr", __spufs_fpcr_read, NULL, sizeof(struct spu_reg128) },
+       { "regs", spufs_regs_dump, NULL, sizeof(struct spu_reg128[128])},
+       { "fpcr", spufs_fpcr_dump, NULL, sizeof(struct spu_reg128) },
        { "lslr", NULL, spufs_lslr_get, 19 },
        { "decr", NULL, spufs_decr_get, 19 },
        { "decr_status", NULL, spufs_decr_status_get, 19 },
-       { "mem", __spufs_mem_read, NULL, LS_SIZE, },
-       { "signal1", __spufs_signal1_read, NULL, sizeof(u32) },
+       { "mem", spufs_mem_dump, NULL, LS_SIZE, },
+       { "signal1", spufs_signal1_dump, NULL, sizeof(u32) },
        { "signal1_type", NULL, spufs_signal1_type_get, 19 },
-       { "signal2", __spufs_signal2_read, NULL, sizeof(u32) },
+       { "signal2", spufs_signal2_dump, NULL, sizeof(u32) },
        { "signal2_type", NULL, spufs_signal2_type_get, 19 },
        { "event_mask", NULL, spufs_event_mask_get, 19 },
        { "event_status", NULL, spufs_event_status_get, 19 },
-       { "mbox_info", __spufs_mbox_info_read, NULL, sizeof(u32) },
-       { "ibox_info", __spufs_ibox_info_read, NULL, sizeof(u32) },
-       { "wbox_info", __spufs_wbox_info_read, NULL, 4 * sizeof(u32)},
-       { "dma_info", __spufs_dma_info_read, NULL, sizeof(struct spu_dma_info)},
-       { "proxydma_info", __spufs_proxydma_info_read,
+       { "mbox_info", spufs_mbox_info_dump, NULL, sizeof(u32) },
+       { "ibox_info", spufs_ibox_info_dump, NULL, sizeof(u32) },
+       { "wbox_info", spufs_wbox_info_dump, NULL, 4 * sizeof(u32)},
+       { "dma_info", spufs_dma_info_dump, NULL, sizeof(struct spu_dma_info)},
+       { "proxydma_info", spufs_proxydma_info_dump,
                           NULL, sizeof(struct spu_proxydma_info)},
        { "object-id", NULL, spufs_object_id_get, 19 },
        { "npc", NULL, spufs_npc_get, 19 },

diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 413c89afe1126e5d24c37d766008002e9ac4a8ba..1ba4d884febfa0c085a07d7f3d56df8ad9168a53 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -337,8 +337,7 @@ void spufs_dma_callback(struct spu *spu, int type);
 extern struct spu_coredump_calls spufs_coredump_calls;
 struct spufs_coredump_reader {
        char *name;
-       ssize_t (*read)(struct spu_context *ctx,
-                       char __user *buffer, size_t size, loff_t *pos);
+       ssize_t (*dump)(struct spu_context *ctx, struct coredump_params *cprm);
        u64 (*get)(struct spu_context *ctx);
        size_t size;
 };