Messages in this thread Patch in this message | | | From | David Howells <> | Subject | [PATCH] NOMMU: Improved handling of get_unmapped_area() errors | Date | Tue, 08 Feb 2005 14:32:05 +0000 |
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The attached patch does two things:
(1) We no longer check the return value of file->f_op->get_unmapped_area() unless we actually called it. We know addr is zero otherwise because we'd've given an error earlier if it wasn't.
(2) If -ENOSYS was returned by that operation, then we assume we actually called a driver (such as the framebuffer driver) that might want to invoke the operation in a lower level driver (such as matroxfb) if one exists, and that it found that one didn't.
We translate the -ENOSYS error into -ENODEV - the error we would have given if the operation was not supplied in the file ops.
Doing this permits us an opportunity for arch_get_unmapped_area() or something else to be called if we want that to happen, particularly in the MMU case.
Signed-Off-By: David Howells <dhowells@redhat.com> --- warthog>diffstat -p1 nommu-2611rc3.diff mm/nommu.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-)
diff -uNrp /warthog/kernels/linux-2.6.11-rc3/mm/nommu.c linux-2.6.11-rc3-frv/mm/nommu.c --- /warthog/kernels/linux-2.6.11-rc3/mm/nommu.c 2005-02-04 11:50:28.000000000 +0000 +++ linux-2.6.11-rc3-frv/mm/nommu.c 2005-02-08 13:54:18.816577889 +0000 @@ -567,12 +567,14 @@ unsigned long do_mmap_pgoff(struct file * that it represents a valid section of the address space * - this is the hook for quasi-memory character devices */ - if (file && file->f_op->get_unmapped_area) + if (file && file->f_op->get_unmapped_area) { addr = file->f_op->get_unmapped_area(file, addr, len, pgoff, flags); - - if (IS_ERR((void *) addr)) { - ret = addr; - goto error; + if (IS_ERR((void *) addr)) { + ret = addr; + if (ret == (unsigned long) -ENOSYS) + ret = (unsigned long) -ENODEV; + goto error; + } } /* we're going to need a VMA struct as well */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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