From 816fd37ee87127911c61b5464dfdd25145b36e1c Mon Sep 17 00:00:00 2001 From: Vladimir 'phcoder' Serbinenko Date: Sun, 10 Mar 2013 18:27:53 +0100 Subject: [PATCH 202/482] * grub-core/fs/hfs.c (grub_hfs_read_file): Avoid divmod64 since the maximum size is 4G - 1 on hfs --- ChangeLog | 5 +++++ grub-core/fs/hfs.c | 15 ++++++++------- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/ChangeLog b/ChangeLog index bc51ae9..931ae8e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,10 @@ 2013-03-10 Vladimir Serbinenko + * 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 + Avoid costly 64-bit division in grub_get_time_ms on most platforms. 2013-03-10 Vladimir Serbinenko diff --git a/grub-core/fs/hfs.c b/grub-core/fs/hfs.c index 73ac7f9..14520c0 100644 --- a/grub-core/fs/hfs.c +++ b/grub-core/fs/hfs.c @@ -244,15 +244,16 @@ grub_hfs_block (struct grub_hfs_data *data, grub_hfs_datarecord_t dat, static grub_ssize_t grub_hfs_read_file (struct grub_hfs_data *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 blockcnt; - blockcnt = grub_divmod64 (((len + pos) - + data->blksz - 1), data->blksz, 0); + /* Files are at most 2G/4G - 1 bytes on hfs. Avoid 64-bit division. + 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_off_t blockoff; @@ -260,7 +261,7 @@ grub_hfs_read_file (struct grub_hfs_data *data, int skipfirst = 0; - grub_divmod64 (pos, data->blksz, &blockoff); + blockoff = pos % data->blksz; blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1); if (grub_errno) @@ -269,7 +270,7 @@ grub_hfs_read_file (struct grub_hfs_data *data, /* Last block. */ 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). */ if (! blockend) @@ -277,7 +278,7 @@ grub_hfs_read_file (struct grub_hfs_data *data, } /* First block. */ - if (i == grub_divmod64 (pos, data->blksz, 0)) + if (i == pos / data->blksz) { skipfirst = blockoff; blockend -= skipfirst; -- 1.8.2.1