On Fri, 10 Dec 2021 21:36:00 +0800 Tiezhu Yang <yangtie...@loongson.cn> wrote:
> In arch/*/kernel/crash_dump*.c, there exist similar code about > copy_oldmem_page(), move copy_to() from vmcore.c to uaccess.h, > and then we can use copy_to() to simplify the related code. > > ... > > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -238,20 +238,6 @@ copy_oldmem_page_encrypted(unsigned long pfn, char *buf, > size_t csize, > return copy_oldmem_page(pfn, buf, csize, offset, userbuf); > } > > -/* > - * Copy to either kernel or user space > - */ > -static int copy_to(void *target, void *src, size_t size, int userbuf) > -{ > - if (userbuf) { > - if (copy_to_user((char __user *) target, src, size)) > - return -EFAULT; > - } else { > - memcpy(target, src, size); > - } > - return 0; > -} > - > #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP > static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int > userbuf) > { > diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h > index ac03940..4a6c3e4 100644 > --- a/include/linux/uaccess.h > +++ b/include/linux/uaccess.h > @@ -201,6 +201,20 @@ copy_to_user(void __user *to, const void *from, unsigned > long n) > return n; > } > > +/* > + * Copy to either kernel or user space > + */ > +static inline int copy_to(void *target, void *src, size_t size, int userbuf) > +{ > + if (userbuf) { > + if (copy_to_user((char __user *) target, src, size)) > + return -EFAULT; > + } else { > + memcpy(target, src, size); > + } > + return 0; > +} > + Ordinarily I'd say "this is too large to be inlined". But the function has only a single callsite per architecture so inlining it won't cause bloat at present. But hopefully copy_to() will get additional callers in the future, in which case it shouldn't be inlined. So I'm thinking it would be best to start out with this as a regular non-inlined function, in lib/usercopy.c. Also, copy_to() is a very poor name for a globally-visible helper function. Better would be copy_to_user_or_kernel(), although that's perhaps a bit long. And the `userbuf' arg should have type bool, yes? _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec