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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-04 10:39:05 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-04 10:50:14 -0800 |
commit | 736706bee3298208343a76096370e4f6a5c55915 (patch) | |
tree | 3e90fd9d540cb15ac671182d52f9a4ade8657c59 /fs/read_write.c | |
parent | 84c4e1f89fefe70554da0ab33be72c9be7994379 (diff) | |
download | linux-stable-736706bee3298208343a76096370e4f6a5c55915.tar.gz linux-stable-736706bee3298208343a76096370e4f6a5c55915.tar.bz2 linux-stable-736706bee3298208343a76096370e4f6a5c55915.zip |
get rid of legacy 'get_ds()' function
Every in-kernel use of this function defined it to KERNEL_DS (either as
an actual define, or as an inline function). It's an entirely
historical artifact, and long long long ago used to actually read the
segment selector valueof '%ds' on x86.
Which in the kernel is always KERNEL_DS.
Inspired by a patch from Jann Horn that just did this for a very small
subset of users (the ones in fs/), along with Al who suggested a script.
I then just took it to the logical extreme and removed all the remaining
gunk.
Roughly scripted with
git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/'
git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d'
plus manual fixups to remove a few unusual usage patterns, the couple of
inline function cases and to fix up a comment that had become stale.
The 'get_ds()' function remains in an x86 kvm selftest, since in user
space it actually does something relevant.
Inspired-by: Jann Horn <jannh@google.com>
Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/read_write.c')
-rw-r--r-- | fs/read_write.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index ff3c5e6f87cf..30df848b7451 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -426,7 +426,7 @@ ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) ssize_t result; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); /* The cast to a user pointer is valid due to the set_fs() */ result = vfs_read(file, (void __user *)buf, count, pos); set_fs(old_fs); @@ -499,7 +499,7 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t return -EINVAL; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); p = (__force const char __user *)buf; if (count > MAX_RW_COUNT) count = MAX_RW_COUNT; @@ -521,7 +521,7 @@ ssize_t kernel_write(struct file *file, const void *buf, size_t count, ssize_t res; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); /* The cast to a user pointer is valid due to the set_fs() */ res = vfs_write(file, (__force const char __user *)buf, count, pos); set_fs(old_fs); |