Messages in this thread | | | Date | Tue, 3 May 2022 09:06:18 +0800 | Subject | Re: [PATCH -next v4 1/7] x86, powerpc: fix function define in copy_mc_to_user | From | Tong Tiangen <> |
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在 2022/5/2 22:24, Christophe Leroy 写道: > > > Le 20/04/2022 à 05:04, Tong Tiangen a écrit : >> x86/powerpc has it's implementation of copy_mc_to_user but not use #define >> to declare. >> >> This may cause problems, for example, if other architectures open >> CONFIG_ARCH_HAS_COPY_MC, but want to use copy_mc_to_user() outside the >> architecture, the code add to include/linux/uaddess.h is as follows: >> >> #ifndef copy_mc_to_user >> static inline unsigned long __must_check >> copy_mc_to_user(void *dst, const void *src, size_t cnt) >> { >> ... >> } >> #endif >> >> Then this definition will conflict with the implementation of x86/powerpc >> and cause compilation errors as follow: >> >> Fixes: ec6347bb4339 ("x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()") > > I don't understand, what does it fix really ? What was the > (existing/real) bug introduced by that patch and that your are fixing ? > > If those defined had been expected and missing, we would have had a > build failure. If you have one, can you describe it ?
There will be build failure after patch 3 is added, there is a little confusing for a reader of this commit in isolation. In the next version, I will put this patch after patch 3.
Thanks, Tong. > >> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> >> --- >> arch/powerpc/include/asm/uaccess.h | 1 + >> arch/x86/include/asm/uaccess.h | 1 + >> 2 files changed, 2 insertions(+) >> >> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h >> index 9b82b38ff867..58dbe8e2e318 100644 >> --- a/arch/powerpc/include/asm/uaccess.h >> +++ b/arch/powerpc/include/asm/uaccess.h >> @@ -358,6 +358,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n) >> >> return n; >> } >> +#define copy_mc_to_user copy_mc_to_user >> #endif >> >> extern long __copy_from_user_flushcache(void *dst, const void __user *src, >> diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h >> index f78e2b3501a1..e18c5f098025 100644 >> --- a/arch/x86/include/asm/uaccess.h >> +++ b/arch/x86/include/asm/uaccess.h >> @@ -415,6 +415,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len); >> >> unsigned long __must_check >> copy_mc_to_user(void *to, const void *from, unsigned len); >> +#define copy_mc_to_user copy_mc_to_user >> #endif >> >> /*
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