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authorDavid Daney <ddaney@caviumnetworks.com>2010-10-14 11:32:33 -0700
committerRalf Baechle <ralf@linux-mips.org>2010-10-29 19:08:53 +0100
commit949e51bea342da838be5295628e4a7ada8bae833 (patch)
tree8967391768d4da3a99a2adf85e0834e0fa7a2009 /arch/mips/include/asm/uaccess.h
parent18d693b3598fdebdd5c65a613221793456a7ce45 (diff)
downloadblackbird-op-linux-949e51bea342da838be5295628e4a7ada8bae833.tar.gz
blackbird-op-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.h4
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"
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