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author | David Daney <ddaney@caviumnetworks.com> | 2010-10-14 20:32:33 +0200 |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2010-10-29 20:08:53 +0200 |
commit | 949e51bea342da838be5295628e4a7ada8bae833 (patch) | |
tree | 8967391768d4da3a99a2adf85e0834e0fa7a2009 /arch/mips/include/asm/uaccess.h | |
parent | MIPS: Allow UserLocal on MIPS_R1 processors (diff) | |
download | linux-949e51bea342da838be5295628e4a7ada8bae833.tar.xz linux-949e51bea342da838be5295628e4a7ada8bae833.zip |
MIPS: Make TASK_SIZE reflect proper size for both 32 and 64 bit processes.
The TASK_SIZE macro should reflect the size of a user process virtual
address space. Previously for 64-bit kernels, this was not the case.
The immediate cause of pain was in
hugetlbfs/inode.c:hugetlb_get_unmapped_area() where 32-bit processes
trying to mmap a huge page would be served a page with an address
outside of the 32-bit address range. But there are other uses of
TASK_SIZE in the kernel as well that would like an accurate value.
The new definition is nice because it now makes TASK_SIZE and
TASK_SIZE_OF() yield the same value for any given process.
For 32-bit kernels there should be no change, although I did factor
out some code in asm/processor.h that became identical for the 32-bit and
64-bit cases.
__UA_LIMIT is now set to ~((1 << SEGBITS) - 1) for 64-bit kernels.
This should eliminate the possibility of getting a
AddressErrorException in the kernel for addresses that pass the
access_ok() test.
With the patch applied, I can still run o32, n32 and n64 processes,
and have an o32 shell fork/exec both n32 and n64 processes.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1701/
Diffstat (limited to 'arch/mips/include/asm/uaccess.h')
-rw-r--r-- | arch/mips/include/asm/uaccess.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h index c2d53c18fd36..653a412c036c 100644 --- a/arch/mips/include/asm/uaccess.h +++ b/arch/mips/include/asm/uaccess.h @@ -35,7 +35,9 @@ #ifdef CONFIG_64BIT -#define __UA_LIMIT (- TASK_SIZE) +extern u64 __ua_limit; + +#define __UA_LIMIT __ua_limit #define __UA_ADDR ".dword" #define __UA_LA "dla" |