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* grub-core/fs/hfs.c (grub_hfs_read_file): Avoid divmod64 since the

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maximum size is 4G - 1 on hfs
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Vladimir 'phcoder' Serbinenko 2013-03-10 18:27:53 +01:00
parent 5341c0fbfc
commit 3dac5878ec
2 changed files with 13 additions and 7 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
2013-03-10 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/fs/hfs.c (grub_hfs_read_file): Avoid divmod64 since the
maximum size is 4G - 1 on hfs
2013-03-10 Vladimir Serbinenko <phcoder@gmail.com> 2013-03-10 Vladimir Serbinenko <phcoder@gmail.com>
Avoid costly 64-bit division in grub_get_time_ms on most platforms. Avoid costly 64-bit division in grub_get_time_ms on most platforms.

15
grub-core/fs/hfs.c
View file

@ -244,15 +244,16 @@ grub_hfs_block (struct grub_hfs_data *data, grub_hfs_datarecord_t dat,
static grub_ssize_t static grub_ssize_t
grub_hfs_read_file (struct grub_hfs_data *data, grub_hfs_read_file (struct grub_hfs_data *data,
grub_disk_read_hook_t read_hook, void *read_hook_data, grub_disk_read_hook_t read_hook, void *read_hook_data,
grub_off_t pos, grub_size_t len, char *buf) grub_uint32_t pos, grub_size_t len, char *buf)
{ {
grub_off_t i; grub_off_t i;
grub_off_t blockcnt; grub_off_t blockcnt;
blockcnt = grub_divmod64 (((len + pos) /* Files are at most 2G/4G - 1 bytes on hfs. Avoid 64-bit division.
+ data->blksz - 1), data->blksz, 0); Moreover len > 0 as checked in upper layer. */
blockcnt = (len + pos - 1) / data->blksz + 1;
for (i = grub_divmod64 (pos, data->blksz, 0); i < blockcnt; i++) for (i = pos / data->blksz; i < blockcnt; i++)
{ {
grub_disk_addr_t blknr; grub_disk_addr_t blknr;
grub_off_t blockoff; grub_off_t blockoff;
@ -260,7 +261,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
int skipfirst = 0; int skipfirst = 0;
grub_divmod64 (pos, data->blksz, &blockoff); blockoff = pos % data->blksz;
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1); blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno) if (grub_errno)
@ -269,7 +270,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
/* Last block. */ /* Last block. */
if (i == blockcnt - 1) if (i == blockcnt - 1)
{ {
grub_divmod64 ((len + pos), data->blksz, &blockend); blockend = (len + pos) % data->blksz;
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */ /* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (! blockend) if (! blockend)
@ -277,7 +278,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
} }
/* First block. */ /* First block. */
if (i == grub_divmod64 (pos, data->blksz, 0)) if (i == pos / data->blksz)
{ {
skipfirst = blockoff; skipfirst = blockoff;
blockend -= skipfirst; blockend -= skipfirst;