Messages in this thread | | | Date | Thu, 3 Jun 2021 13:37:09 +0200 | From | Greg KH <> | Subject | Re: [PATCH v3 1/3] lib: bitmap: introduce bitmap_print_to_buf |
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On Thu, Jun 03, 2021 at 07:21:30PM +0800, tiantao (H) wrote: > > 在 2021/6/3 18:49, Greg KH 写道: > > On Thu, Jun 03, 2021 at 06:33:25PM +0800, tiantao (H) wrote: > > > 在 2021/6/3 17:50, Andy Shevchenko 写道: > > > > On Thu, Jun 03, 2021 at 05:22:40PM +0800, Tian Tao wrote: > > > > > New API bitmap_print_to_buf() with bin_attribute to avoid maskp > > > > > exceeding PAGE_SIZE. bitmap_print_to_pagebuf() is a special case > > > > > of bitmap_print_to_buf(), so in bitmap_print_to_pagebuf() call > > > > > bitmap_print_to_buf(). > > > > ... > > > > > > > > > /** > > > > > + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string > > > > > + * @list: indicates whether the bitmap must be list > > > > > + * @buf: the kernel space buffer to read to > > > > > + * @maskp: pointer to bitmap to convert > > > > > + * @nmaskbits: size of bitmap, in bits > > > > > + * @off: offset in data buffer below > > > > > + * @count: the maximum number of bytes to print > > > > > + * > > > > > + * The role of bitmap_print_to_buf() and bitmap_print_to_pagebuf() is > > > > > + * the same, the difference is that buf of bitmap_print_to_buf() > > > > > + * can be more than one pagesize. > > > > > + */ > > > > > +int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, > > > > > + int nmaskbits, loff_t off, size_t count) > > > > > +{ > > > > > + const char *fmt = list ? "%*pbl\n" : "%*pb\n"; > > > > > + ssize_t size; > > > > > + void *data; > > > > > + > > > > > + if (off == LLONG_MAX && count == PAGE_SIZE - offset_in_page(buf)) > > > > > + return scnprintf(buf, count, fmt, nmaskbits, maskp); > > > > > + > > > > > + data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); > > > > > + if (!data) > > > > > + return -ENOMEM; > > > > > + > > > > > + size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); > > > > Are you sure you have put parameters in the correct order? > > > yes, I already test it. > > Great, can you add the test to the patch series as well so that we can > > make sure it does not break in the future? > How do I do this? Do I need to provide a kselftest ?
That would be wonderful, great idea!
thanks,
greg k-h
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