From: Tony Luck Date: Thu, 20 Nov 2008 21:27:12 +0000 (-0800) Subject: [IA64] Rationalize kernel mode alignment checking X-Git-Tag: v2.6.28-rc6~1^2~4 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=b704882e70d87d7f56db5ff17e2253f3fa90e4f3;p=linux-2.6-omap-h63xx.git [IA64] Rationalize kernel mode alignment checking Itanium processors can handle some misaligned data accesses. They also provide a mode where all such accesses are forced to trap. The kernel was schizophrenic about use of this mode: * Base kernel code ran in permissive mode where the only traps generated were from those cases that the h/w could not handle. * Interrupt, syscall and trap code ran in strict mode where all unaligned accesses caused traps to the 0x5a00 unaligned reference vector. Use strict alignment checking throughout the kernel, but make sure that we continue to let user mode use more relaxed mode as the default. Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S index 7ef0c594f5e..d435f4a7a96 100644 --- a/arch/ia64/kernel/entry.S +++ b/arch/ia64/kernel/entry.S @@ -499,6 +499,7 @@ GLOBAL_ENTRY(prefetch_stack) END(prefetch_stack) GLOBAL_ENTRY(kernel_execve) + rum psr.ac mov r15=__NR_execve // put syscall number in place break __BREAK_SYSCALL br.ret.sptk.many rp diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index 66e491d8baa..59301c47280 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -260,7 +260,7 @@ start_ap: * Switch into virtual mode: */ movl r16=(IA64_PSR_IT|IA64_PSR_IC|IA64_PSR_DT|IA64_PSR_RT|IA64_PSR_DFH|IA64_PSR_BN \ - |IA64_PSR_DI) + |IA64_PSR_DI|IA64_PSR_AC) ;; mov cr.ipsr=r16 movl r17=1f