2023-09-25 19:11:08

by David Howells

Subject: [PATCH v7 02/12] iov_iter, x86: Be consistent about the __user tag on copy_mc_to_user()

copy_mc_to_user() has the destination marked __user on powerpc, but not on
x86; the latter results in a sparse warning in lib/iov_iter.c.

Fix this by applying the tag on x86 too.

Fixes: ec6347bb4339 ("x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()")
Signed-off-by: David Howells <[email protected]>
cc: Dan Williams <[email protected]>
cc: Thomas Gleixner <[email protected]>
cc: Ingo Molnar <[email protected]>
cc: Borislav Petkov <[email protected]>
cc: Dave Hansen <[email protected]>
cc: "H. Peter Anvin" <[email protected]>
cc: Alexander Viro <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Christoph Hellwig <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: Linus Torvalds <[email protected]>
cc: David Laight <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
arch/x86/include/asm/uaccess.h | 2 +-
arch/x86/lib/copy_mc.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 8bae40a66282..5c367c1290c3 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -496,7 +496,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);
#define copy_mc_to_kernel copy_mc_to_kernel

unsigned long __must_check
-copy_mc_to_user(void *to, const void *from, unsigned len);
+copy_mc_to_user(void __user *to, const void *from, unsigned len);
#endif

/*
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 80efd45a7761..6e8b7e600def 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -70,23 +70,23 @@ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigne
}
EXPORT_SYMBOL_GPL(copy_mc_to_kernel);

-unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
+unsigned long __must_check copy_mc_to_user(void __user *dst, const void *src, unsigned len)
{
unsigned long ret;

if (copy_mc_fragile_enabled) {
__uaccess_begin();
- ret = copy_mc_fragile(dst, src, len);
+ ret = copy_mc_fragile((__force void *)dst, src, len);
__uaccess_end();
return ret;
}

if (static_cpu_has(X86_FEATURE_ERMS)) {
__uaccess_begin();
- ret = copy_mc_enhanced_fast_string(dst, src, len);
+ ret = copy_mc_enhanced_fast_string((__force void *)dst, src, len);
__uaccess_end();
return ret;
}

- return copy_user_generic(dst, src, len);
+ return copy_user_generic((__force void *)dst, src, len);
}

2023-09-28 17:54:55

by Borislav Petkov

Subject: Re: [PATCH v7 02/12] iov_iter, x86: Be consistent about the __user tag on copy_mc_to_user()

On Mon, Sep 25, 2023 at 01:02:59PM +0100, David Howells wrote:
> copy_mc_to_user() has the destination marked __user on powerpc, but not on
> x86; the latter results in a sparse warning in lib/iov_iter.c.
>
> Fix this by applying the tag on x86 too.
>
> Fixes: ec6347bb4339 ("x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()")
> Signed-off-by: David Howells <[email protected]>
> cc: Dan Williams <[email protected]>
> cc: Thomas Gleixner <[email protected]>
> cc: Ingo Molnar <[email protected]>
> cc: Borislav Petkov <[email protected]>
> cc: Dave Hansen <[email protected]>
> cc: "H. Peter Anvin" <[email protected]>
> cc: Alexander Viro <[email protected]>
> cc: Jens Axboe <[email protected]>
> cc: Christoph Hellwig <[email protected]>
> cc: Christian Brauner <[email protected]>
> cc: Matthew Wilcox <[email protected]>
> cc: Linus Torvalds <[email protected]>
> cc: David Laight <[email protected]>
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> ---
> arch/x86/include/asm/uaccess.h | 2 +-
> arch/x86/lib/copy_mc.c | 8 ++++----
> 2 files changed, 5 insertions(+), 5 deletions(-)

Acked-by: Borislav Petkov (AMD) <[email protected]>

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette