Messages in this thread | | | Date | Mon, 01 Dec 2008 16:14:18 -0800 (PST) | Subject | Re: sg_set_page not usable for .bss? | From | David Miller <> |
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From: Jan Engelhardt <jengelh@medozas.de> Date: Tue, 2 Dec 2008 01:13:34 +0100 (CET)
> > On Tuesday 2008-12-02 01:10, David Miller wrote: > >> On Monday 2008-12-01 23:02, John Haxby wrote: > >> >>>+ sg_init_table(sg, 2); > >> >>>+ sg_set_buf(&sg[0], data, n); > >> >>>+ strcpy(digest_password, sysrq_password); > >> >>>+ i = strlen(digest_password); > >> >>>+ sg_set_buf(&sg[1], digest_password, i); > >> >> > >> >> Could we directly use sysrq_password instead of copying it to > >> >> digest_password first? > >> > > >> > No :-) Eventually I discovered the reason my code wasn't working > >> > boils down to the definition of sg_set_buf: > >> > > >> > sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf)) > >> > > >> > which doesn't work for sysrq_password. I don't know why I'll > >> > double check. > >> > >> Well, sysrq_password is in the .bss section, where as digest_password > >> is on the heap due to being kmalloc'ed. Maybe that makes a difference? > >> Someone more versed with the virtual memory layer might know. > > > >You can't use these interfaces on kernel image addresses. > > > Great :-) So what is the best way to use the SHA1 crypto algo > with in-kernel addresses?
kmalloc and copy it there, or something like that, you just can't use in-kernel addresses, ever.
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