From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 2/4] uaccess: Selectively open read or write user access
Date: Tue, 4 Feb 2020 07:37:53 +0000 (UTC) [thread overview]
Message-ID: <24e8d1d49af2664f945e7115de3dd0df2d6b5670.1580801787.git.christophe.leroy@c-s.fr> (raw)
In-Reply-To: <f96ed94dc57ea810b738c4e02263e08c2c8781b6.1580801787.git.christophe.leroy@c-s.fr>
When opening user access to only perform reads, only open read access.
When opening user access to only perform writes, only open write
access.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
fs/readdir.c | 12 ++++++------
kernel/compat.c | 12 ++++++------
kernel/exit.c | 12 ++++++------
lib/strncpy_from_user.c | 4 ++--
lib/strnlen_user.c | 4 ++--
lib/usercopy.c | 6 +++---
6 files changed, 25 insertions(+), 25 deletions(-)
diff --git a/fs/readdir.c b/fs/readdir.c
index de2eceffdee8..ed6aaad451aa 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -242,7 +242,7 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,
return -EINTR;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
- if (!user_access_begin(prev, reclen + prev_reclen))
+ if (!user_write_access_begin(prev, reclen + prev_reclen))
goto efault;
/* This might be 'dirent->d_off', but if so it will get overwritten */
@@ -251,14 +251,14 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
- user_access_end();
+ user_write_access_end();
buf->current_dir = (void __user *)dirent + reclen;
buf->prev_reclen = reclen;
buf->count -= reclen;
return 0;
efault_end:
- user_access_end();
+ user_write_access_end();
efault:
buf->error = -EFAULT;
return -EFAULT;
@@ -327,7 +327,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
return -EINTR;
dirent = buf->current_dir;
prev = (void __user *)dirent - prev_reclen;
- if (!user_access_begin(prev, reclen + prev_reclen))
+ if (!user_write_access_begin(prev, reclen + prev_reclen))
goto efault;
/* This might be 'dirent->d_off', but if so it will get overwritten */
@@ -336,7 +336,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
unsafe_put_user(d_type, &dirent->d_type, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
- user_access_end();
+ user_write_access_end();
buf->prev_reclen = reclen;
buf->current_dir = (void __user *)dirent + reclen;
@@ -344,7 +344,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
return 0;
efault_end:
- user_access_end();
+ user_write_access_end();
efault:
buf->error = -EFAULT;
return -EFAULT;
diff --git a/kernel/compat.c b/kernel/compat.c
index 95005f849c68..7b8b59e039ba 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -263,7 +263,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!user_access_begin(umask, bitmap_size / 8))
+ if (!user_read_access_begin(umask, bitmap_size / 8))
return -EFAULT;
while (nr_compat_longs > 1) {
@@ -275,11 +275,11 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
}
if (nr_compat_longs)
unsafe_get_user(*mask, umask++, Efault);
- user_access_end();
+ user_read_access_end();
return 0;
Efault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}
@@ -292,7 +292,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!user_access_begin(umask, bitmap_size / 8))
+ if (!user_write_access_begin(umask, bitmap_size / 8))
return -EFAULT;
while (nr_compat_longs > 1) {
@@ -303,10 +303,10 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
}
if (nr_compat_longs)
unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
- user_access_end();
+ user_write_access_end();
return 0;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
diff --git a/kernel/exit.c b/kernel/exit.c
index 2833ffb0c211..b33d3bcf9c9f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1563,7 +1563,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
if (!infop)
return err;
- if (!user_access_begin(infop, sizeof(*infop)))
+ if (!user_write_access_begin(infop, sizeof(*infop)))
return -EFAULT;
unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1572,10 +1572,10 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
unsafe_put_user(info.pid, &infop->si_pid, Efault);
unsafe_put_user(info.uid, &infop->si_uid, Efault);
unsafe_put_user(info.status, &infop->si_status, Efault);
- user_access_end();
+ user_write_access_end();
return err;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
@@ -1690,7 +1690,7 @@ COMPAT_SYSCALL_DEFINE5(waitid,
if (!infop)
return err;
- if (!user_access_begin(infop, sizeof(*infop)))
+ if (!user_write_access_begin(infop, sizeof(*infop)))
return -EFAULT;
unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1699,10 +1699,10 @@ COMPAT_SYSCALL_DEFINE5(waitid,
unsafe_put_user(info.pid, &infop->si_pid, Efault);
unsafe_put_user(info.uid, &infop->si_uid, Efault);
unsafe_put_user(info.status, &infop->si_status, Efault);
- user_access_end();
+ user_write_access_end();
return err;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
#endif
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 706020b06617..b90ec550183a 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -116,9 +116,9 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
kasan_check_write(dst, count);
check_object_size(dst, count, false);
- if (user_access_begin(src, max)) {
+ if (user_read_access_begin(src, max)) {
retval = do_strncpy_from_user(dst, src, count, max);
- user_access_end();
+ user_read_access_end();
return retval;
}
}
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 41670d4a5816..1616710b8a82 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -109,9 +109,9 @@ long strnlen_user(const char __user *str, long count)
if (max > count)
max = count;
- if (user_access_begin(str, max)) {
+ if (user_read_access_begin(str, max)) {
retval = do_strnlen_user(str, count, max);
- user_access_end();
+ user_read_access_end();
return retval;
}
}
diff --git a/lib/usercopy.c b/lib/usercopy.c
index cbb4d9ec00f2..ca2a697a2061 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -58,7 +58,7 @@ int check_zeroed_user(const void __user *from, size_t size)
from -= align;
size += align;
- if (!user_access_begin(from, size))
+ if (!user_read_access_begin(from, size))
return -EFAULT;
unsafe_get_user(val, (unsigned long __user *) from, err_fault);
@@ -79,10 +79,10 @@ int check_zeroed_user(const void __user *from, size_t size)
val &= aligned_byte_mask(size);
done:
- user_access_end();
+ user_read_access_end();
return (val == 0);
err_fault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}
EXPORT_SYMBOL(check_zeroed_user);
--
2.25.0
next prev parent reply other threads:[~2020-02-04 7:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 7:37 [PATCH 1/4] uaccess: Add user_read_access_begin/end and user_write_access_begin/end Christophe Leroy
2020-02-04 7:37 ` Christophe Leroy [this message]
2020-02-04 7:37 ` [PATCH 3/4] drm/i915/gem: Replace user_access_begin by user_write_access_begin Christophe Leroy
2020-02-04 7:37 ` [PATCH 4/4] powerpc/uaccess: Implement user_read_access_begin and user_write_access_begin Christophe Leroy
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