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| author | Vineet Gupta | 2013-01-23 12:00:36 +0100 |
|---|---|---|
| committer | Vineet Gupta | 2013-02-15 18:46:06 +0100 |
| commit | 2e651ea1596b0ee25af4fcdc4cd13cbb33ffc254 (patch) | |
| tree | 51210f1cd80327a00e2fd4b0d20849b6329925d6 /arch/arc/Kconfig | |
| parent | sysctl: Enable PARISC "unaligned-trap" to be used cross-arch (diff) | |
| download | kernel-qcow2-linux-2e651ea1596b0ee25af4fcdc4cd13cbb33ffc254.tar.gz kernel-qcow2-linux-2e651ea1596b0ee25af4fcdc4cd13cbb33ffc254.tar.xz kernel-qcow2-linux-2e651ea1596b0ee25af4fcdc4cd13cbb33ffc254.zip | |
ARC: Unaligned access emulation
ARC700 doesn't natively support unaligned access, but can be emulated
-Unaligned Access Exception
-Disassembly at the Fault address to find the exact insn (long/short)
Also per Arnd's comment, we runtime control it using 2 sysctl knobs:
* SYSCTL_ARCH_UNALIGN_ALLOW: Runtime enable/disble
* SYSCTL_ARCH_UNALIGN_NO_WARN: Warn on each emulation attempt
Originally contributed by Tim Yao <tim.yao@amlogic.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Tim Yao <tim.yao@amlogic.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arc/Kconfig')
| -rw-r--r-- | arch/arc/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index cde8d3fcec94..f8042835e746 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -336,6 +336,17 @@ config ARC_CURR_IN_REG This reserved Register R25 to point to Current Task in kernel mode. This saves memory access for each such access + +config ARC_MISALIGN_ACCESS + bool "Emulate unaligned memory access (userspace only)" + default N + select SYSCTL_ARCH_UNALIGN_NO_WARN + select SYSCTL_ARCH_UNALIGN_ALLOW + help + This enables misaligned 16 & 32 bit memory access from user space. + Use ONLY-IF-ABS-NECESSARY as it will be very slow and also can hide + potential bugs in code + config ARC_STACK_NONEXEC bool "Make stack non-executable" default n |