[IA64] MCA recovery improvements
Jack Steiner uncovered some opportunities for improvement in
the MCA recovery code.
1) Set bsp to save registers on the kernel stack.
2) Disable interrupts while in the MCA recovery code.
3) Change the way the user process is killed, to avoid
a panic in schedule.
Testing shows that these changes make the recovery code much
more reliable with the 2.6.12 kernel.
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index ab47817..abc0113 100644
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -132,8 +132,7 @@
spin_unlock(&mca_bh_lock);
/* This process is about to be killed itself */
- force_sig(SIGKILL, current);
- schedule();
+ do_exit(SIGKILL);
}
/**
@@ -439,6 +438,7 @@
psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
psr2->cpl = 0;
psr2->ri = 0;
+ psr2->i = 0;
return 1;
}
diff --git a/arch/ia64/kernel/mca_drv_asm.S b/arch/ia64/kernel/mca_drv_asm.S
index bcfa05a..2d7e021 100644
--- a/arch/ia64/kernel/mca_drv_asm.S
+++ b/arch/ia64/kernel/mca_drv_asm.S
@@ -10,6 +10,7 @@
#include <asm/asmmacro.h>
#include <asm/processor.h>
+#include <asm/ptrace.h>
GLOBAL_ENTRY(mca_handler_bhhook)
invala // clear RSE ?
@@ -20,12 +21,21 @@
;;
alloc r16=ar.pfs,0,2,1,0 // make a new frame
;;
+ mov ar.rsc=0
+ ;;
mov r13=IA64_KR(CURRENT) // current task pointer
;;
- adds r12=IA64_TASK_THREAD_KSP_OFFSET,r13
+ mov r2=r13
;;
- ld8 r12=[r12] // stack pointer
+ addl r22=IA64_RBS_OFFSET,r2
;;
+ mov ar.bspstore=r22
+ ;;
+ addl sp=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2
+ ;;
+ adds r2=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
+ ;;
+ st1 [r2]=r0 // clear current->thread.on_ustack flag
mov loc0=r16
movl loc1=mca_handler_bh // recovery C function
;;
@@ -34,7 +44,9 @@
;;
mov loc1=rp
;;
- br.call.sptk.many rp=b6 // not return ...
+ ssm psr.i
+ ;;
+ br.call.sptk.many rp=b6 // does not return ...
;;
mov ar.pfs=loc0
mov rp=loc1
