Messages in this thread | | | From | nathan.zook@amd ... | Subject | RE: mmapping of page 0xfffff000 impossible ? | Date | Sun, 10 Oct 1999 22:33:10 -0500 |
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include/asm-i386/fixmap.h
"Leave one empty page between vmalloc'ed areas and the start of the fixmap, and leave one page empty at the top of mem."
I would guess that you can't map the fixmap, either.
Nathan
> -----Original Message----- > From: root [SMTP:koenig@tat.physik.uni-tuebingen.de] > Sent: Sunday, October 10, 1999 9:53 PM > To: linux-kernel-list > Cc: Egbert Eich > Subject: mmapping of page 0xfffff000 impossible ? > > why isn't it possible to mmap the very last page in 32bit address space ? > > strace output for 2.2.12 of the small sample program below: > open("/dev/mem", O_RDWR) = 3 > mmap(NULL, 61440, PROT_READ, MAP_SHARED, 3, 0xffff0000) = 0x4011b000 > mmap(NULL, 61441, PROT_READ, MAP_SHARED, 3, 0xffff0000) = -1 EINVAL > (Invalid argument) > > -------------------------------------------------------------------------- > ----- > #include <unistd.h> > #include <sys/mman.h> > #include <fcntl.h> > main() > { > int f; > void *p; > > f = open("/dev/mem", O_RDWR); > > /* this will work ... */ > p = mmap(NULL, 0xf000, PROT_READ, MAP_SHARED, f, 0xffff0000); > > /* this one won't :-( */ > p = mmap(NULL, 0xf001, PROT_READ, MAP_SHARED, f, 0xffff0000); > } > -------------------------------------------------------------------------- > ----- > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
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