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authorRuss Anderson <rja@sgi.com>2006-03-24 09:49:52 -0800
committerTony Luck <tony.luck@intel.com>2006-03-24 09:49:52 -0800
commitd2a28ad9fa7bf16761d070d8a3338375e1574b32 (patch)
tree9da2c18c91a4ee12fa6a9b2d23dcb55d13dd0ca8 /arch
parenta5b00bb4fe60796c791238cf5653b82110031c93 (diff)
downloadlinux-linaro-d2a28ad9fa7bf16761d070d8a3338375e1574b32.tar.gz
[IA64] MCA recovery: kernel context recovery table
Memory errors encountered by user applications may surface when the CPU is running in kernel context. The current code will not attempt recovery if the MCA surfaces in kernel context (privilage mode 0). This patch adds a check for cases where the user initiated the load that surfaces in kernel interrupt code. An example is a user process lauching a load from memory and the data in memory had bad ECC. Before the bad data gets to the CPU register, and interrupt comes in. The code jumps to the IVT interrupt entry point and begins execution in kernel context. The process of saving the user registers (SAVE_REST) causes the bad data to be loaded into a CPU register, triggering the MCA. The MCA surfaces in kernel context, even though the load was initiated from user context. As suggested by David and Tony, this patch uses an exception table like approach, puting the tagged recovery addresses in a searchable table. One difference from the exception table is that MCAs do not surface in precise places (such as with a TLB miss), so instead of tagging specific instructions, address ranges are registers. A single macro is used to do the tagging, with the input parameter being the label of the starting address and the macro being the ending address. This limits clutter in the code. This patch only tags one spot, the interrupt ivt entry. Testing showed that spot to be a "heavy hitter" with MCAs surfacing while saving user registers. Other spots can be added as needed by adding a single macro. Signed-off-by: Russ Anderson (rja@sgi.com) Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/ia64/kernel/ivt.S1
-rw-r--r--arch/ia64/kernel/mca.c98
-rw-r--r--arch/ia64/kernel/mca_drv.c22
-rw-r--r--arch/ia64/kernel/mca_drv.h7
-rw-r--r--arch/ia64/kernel/mca_drv_asm.S13
-rw-r--r--arch/ia64/kernel/vmlinux.lds.S9
6 files changed, 109 insertions, 41 deletions
diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S
index dcd906fe574..829a43cab79 100644
--- a/arch/ia64/kernel/ivt.S
+++ b/arch/ia64/kernel/ivt.S
@@ -865,6 +865,7 @@ ENTRY(interrupt)
;;
SAVE_REST
;;
+ MCA_RECOVER_RANGE(interrupt)
alloc r14=ar.pfs,0,0,2,0 // must be first in an insn group
mov out0=cr.ivr // pass cr.ivr as first arg
add out1=16,sp // pass pointer to pt_regs as second arg
diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index cedcae713e9..87ff7fe33cf 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -83,6 +83,7 @@
#include <asm/irq.h>
#include <asm/hw_irq.h>
+#include "mca_drv.h"
#include "entry.h"
#if defined(IA64_MCA_DEBUG_INFO)
@@ -281,6 +282,50 @@ ia64_mca_log_sal_error_record(int sal_info_type)
ia64_sal_clear_state_info(sal_info_type);
}
+/*
+ * search_mca_table
+ * See if the MCA surfaced in an instruction range
+ * that has been tagged as recoverable.
+ *
+ * Inputs
+ * first First address range to check
+ * last Last address range to check
+ * ip Instruction pointer, address we are looking for
+ *
+ * Return value:
+ * 1 on Success (in the table)/ 0 on Failure (not in the table)
+ */
+int
+search_mca_table (const struct mca_table_entry *first,
+ const struct mca_table_entry *last,
+ unsigned long ip)
+{
+ const struct mca_table_entry *curr;
+ u64 curr_start, curr_end;
+
+ curr = first;
+ while (curr <= last) {
+ curr_start = (u64) &curr->start_addr + curr->start_addr;
+ curr_end = (u64) &curr->end_addr + curr->end_addr;
+
+ if ((ip >= curr_start) && (ip <= curr_end)) {
+ return 1;
+ }
+ curr++;
+ }
+ return 0;
+}
+
+/* Given an address, look for it in the mca tables. */
+int mca_recover_range(unsigned long addr)
+{
+ extern struct mca_table_entry __start___mca_table[];
+ extern struct mca_table_entry __stop___mca_table[];
+
+ return search_mca_table(__start___mca_table, __stop___mca_table-1, addr);
+}
+EXPORT_SYMBOL_GPL(mca_recover_range);
+
#ifdef CONFIG_ACPI
int cpe_vector = -1;
@@ -747,31 +792,34 @@ ia64_mca_modify_original_stack(struct pt_regs *regs,
ia64_mca_modify_comm(previous_current);
goto no_mod;
}
- if (r13 != sos->prev_IA64_KR_CURRENT) {
- msg = "inconsistent previous current and r13";
- goto no_mod;
- }
- if ((r12 - r13) >= KERNEL_STACK_SIZE) {
- msg = "inconsistent r12 and r13";
- goto no_mod;
- }
- if ((ar_bspstore - r13) >= KERNEL_STACK_SIZE) {
- msg = "inconsistent ar.bspstore and r13";
- goto no_mod;
- }
- va.p = old_bspstore;
- if (va.f.reg < 5) {
- msg = "old_bspstore is in the wrong region";
- goto no_mod;
- }
- if ((ar_bsp - r13) >= KERNEL_STACK_SIZE) {
- msg = "inconsistent ar.bsp and r13";
- goto no_mod;
- }
- size += (ia64_rse_skip_regs(old_bspstore, slots) - old_bspstore) * 8;
- if (ar_bspstore + size > r12) {
- msg = "no room for blocked state";
- goto no_mod;
+
+ if (!mca_recover_range(ms->pmsa_iip)) {
+ if (r13 != sos->prev_IA64_KR_CURRENT) {
+ msg = "inconsistent previous current and r13";
+ goto no_mod;
+ }
+ if ((r12 - r13) >= KERNEL_STACK_SIZE) {
+ msg = "inconsistent r12 and r13";
+ goto no_mod;
+ }
+ if ((ar_bspstore - r13) >= KERNEL_STACK_SIZE) {
+ msg = "inconsistent ar.bspstore and r13";
+ goto no_mod;
+ }
+ va.p = old_bspstore;
+ if (va.f.reg < 5) {
+ msg = "old_bspstore is in the wrong region";
+ goto no_mod;
+ }
+ if ((ar_bsp - r13) >= KERNEL_STACK_SIZE) {
+ msg = "inconsistent ar.bsp and r13";
+ goto no_mod;
+ }
+ size += (ia64_rse_skip_regs(old_bspstore, slots) - old_bspstore) * 8;
+ if (ar_bspstore + size > r12) {
+ msg = "no room for blocked state";
+ goto no_mod;
+ }
}
ia64_mca_modify_comm(previous_current);
diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index e883d85906d..37c88eb5587 100644
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -6,6 +6,7 @@
* Copyright (C) Hidetoshi Seto (seto.hidetoshi@jp.fujitsu.com)
* Copyright (C) 2005 Silicon Graphics, Inc
* Copyright (C) 2005 Keith Owens <kaos@sgi.com>
+ * Copyright (C) 2006 Russ Anderson <rja@sgi.com>
*/
#include <linux/config.h>
#include <linux/types.h>
@@ -121,11 +122,12 @@ mca_page_isolate(unsigned long paddr)
*/
void
-mca_handler_bh(unsigned long paddr)
+mca_handler_bh(unsigned long paddr, void *iip, unsigned long ipsr)
{
- printk(KERN_ERR
- "OS_MCA: process [pid: %d](%s) encounters MCA (paddr=%lx)\n",
- current->pid, current->comm, paddr);
+ printk(KERN_ERR "OS_MCA: process [cpu %d, pid: %d, uid: %d, "
+ "iip: %p, psr: 0x%lx,paddr: 0x%lx](%s) encounters MCA.\n",
+ raw_smp_processor_id(), current->pid, current->uid,
+ iip, ipsr, paddr, current->comm);
spin_lock(&mca_bh_lock);
switch (mca_page_isolate(paddr)) {
@@ -442,21 +444,26 @@ recover_from_read_error(slidx_table_t *slidx,
if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
return 0;
psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
+ psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
/*
* Check the privilege level of interrupted context.
* If it is user-mode, then terminate affected process.
*/
- if (psr1->cpl != 0) {
+
+ pmsa = sos->pal_min_state;
+ if (psr1->cpl != 0 ||
+ ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
smei = peidx_bus_check(peidx, 0);
if (smei->valid.target_identifier) {
/*
* setup for resume to bottom half of MCA,
* "mca_handler_bhhook"
*/
- pmsa = sos->pal_min_state;
- /* pass to bhhook as 1st argument (gr8) */
+ /* pass to bhhook as argument (gr8, ...) */
pmsa->pmsa_gr[8-1] = smei->target_identifier;
+ pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
+ pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
/* set interrupted return address (but no use) */
pmsa->pmsa_br0 = pmsa->pmsa_iip;
/* change resume address to bottom half */
@@ -466,6 +473,7 @@ recover_from_read_error(slidx_table_t *slidx,
psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
psr2->cpl = 0;
psr2->ri = 0;
+ psr2->bn = 1;
psr2->i = 0;
return 1;
diff --git a/arch/ia64/kernel/mca_drv.h b/arch/ia64/kernel/mca_drv.h
index e2f6fa1e0ef..31a2e52bb16 100644
--- a/arch/ia64/kernel/mca_drv.h
+++ b/arch/ia64/kernel/mca_drv.h
@@ -111,3 +111,10 @@ typedef struct slidx_table {
slidx_foreach_entry(__pos, &((slidx)->sec)) { __count++; }\
__count; })
+struct mca_table_entry {
+ int start_addr; /* location-relative starting address of MCA recoverable range */
+ int end_addr; /* location-relative ending address of MCA recoverable range */
+};
+
+extern const struct mca_table_entry *search_mca_tables (unsigned long addr);
+extern int mca_recover_range(unsigned long);
diff --git a/arch/ia64/kernel/mca_drv_asm.S b/arch/ia64/kernel/mca_drv_asm.S
index 3f298ee4d00..e6a580d354b 100644
--- a/arch/ia64/kernel/mca_drv_asm.S
+++ b/arch/ia64/kernel/mca_drv_asm.S
@@ -14,15 +14,12 @@
GLOBAL_ENTRY(mca_handler_bhhook)
invala // clear RSE ?
- ;;
cover
;;
clrrrb
;;
- alloc r16=ar.pfs,0,2,1,0 // make a new frame
- ;;
+ alloc r16=ar.pfs,0,2,3,0 // make a new frame
mov ar.rsc=0
- ;;
mov r13=IA64_KR(CURRENT) // current task pointer
;;
mov r2=r13
@@ -30,7 +27,6 @@ GLOBAL_ENTRY(mca_handler_bhhook)
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
@@ -40,12 +36,12 @@ GLOBAL_ENTRY(mca_handler_bhhook)
movl loc1=mca_handler_bh // recovery C function
;;
mov out0=r8 // poisoned address
+ mov out1=r9 // iip
+ mov out2=r10 // psr
mov b6=loc1
;;
mov loc1=rp
- ;;
- ssm psr.i
- ;;
+ ssm psr.i | psr.ic
br.call.sptk.many rp=b6 // does not return ...
;;
mov ar.pfs=loc0
@@ -53,5 +49,4 @@ GLOBAL_ENTRY(mca_handler_bhhook)
;;
mov r8=r0
br.ret.sptk.many rp
- ;;
END(mca_handler_bhhook)
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 632d65cc068..0b9e56dd7f0 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -130,6 +130,15 @@ SECTIONS
__initcall_end = .;
}
+ /* MCA table */
+ . = ALIGN(16);
+ __mca_table : AT(ADDR(__mca_table) - LOAD_OFFSET)
+ {
+ __start___mca_table = .;
+ *(__mca_table)
+ __stop___mca_table = .;
+ }
+
.data.patch.vtop : AT(ADDR(.data.patch.vtop) - LOAD_OFFSET)
{
__start___vtop_patchlist = .;