Author: cognet
Date: Thu Feb 12 23:23:30 2009
New Revision: 188540
URL: http://svn.freebsd.org/changeset/base/188540
Log:
To prevent various race conditions in the RAS code, store and restore the
values in ARM_RAS_START and ARM_RAS_END at context switch time.
MFC after: 1 week
Modified:
head/sys/arm/arm/genassym.c
head/sys/arm/arm/swtch.S
head/sys/arm/include/proc.h
head/sys/arm/include/sysarch.h
Modified: head/sys/arm/arm/genassym.c
==============================================================================
--- head/sys/arm/arm/genassym.c Thu Feb 12 22:55:39 2009 (r188539)
+++ head/sys/arm/arm/genassym.c Thu Feb 12 23:23:30 2009 (r188540)
@@ -96,6 +96,8 @@ ASSYM(TD_FRAME, offsetof(struct thread,
ASSYM(TD_MD, offsetof(struct thread, td_md));
ASSYM(TD_LOCK, offsetof(struct thread, td_lock));
ASSYM(MD_TP, offsetof(struct mdthread, md_tp));
+ASSYM(MD_RAS_START, offsetof(struct mdthread, md_ras_start));
+ASSYM(MD_RAS_END, offsetof(struct mdthread, md_ras_end));
ASSYM(TF_R0, offsetof(struct trapframe, tf_r0));
ASSYM(TF_R1, offsetof(struct trapframe, tf_r1));
Modified: head/sys/arm/arm/swtch.S
==============================================================================
--- head/sys/arm/arm/swtch.S Thu Feb 12 22:55:39 2009 (r188539)
+++ head/sys/arm/arm/swtch.S Thu Feb 12 23:23:30 2009 (r188540)
@@ -205,8 +205,12 @@ ENTRY(cpu_throw)
/* Set the new tp */
ldr r6, [r5, #(TD_MD + MD_TP)]
- ldr r5, =ARM_TP_ADDRESS
- strt r6, [r5]
+ ldr r4, =ARM_TP_ADDRESS
+ str r6, [r4]
+ ldr r6, [r5, #(TD_MD + MD_RAS_START)]
+ str r6, [r4, #4] /* ARM_RAS_START */
+ ldr r6, [r5, #(TD_MD + MD_RAS_END)]
+ str r6, [r4, #4] /* ARM_RAS_END */
/* Hook in a new pcb */
ldr r6, .Lcurpcb
@@ -265,12 +269,20 @@ ENTRY(cpu_switch)
*/
/* Store the old tp */
ldr r3, =ARM_TP_ADDRESS
- ldrt r9, [r3]
+ ldr r9, [r3]
str r9, [r0, #(TD_MD + MD_TP)]
+ ldr r9, [r3, #4]
+ str r9, [r0, #(TD_MD + MD_RAS_START)]
+ ldr r9, [r3, #8]
+ str r9, [r0, #(TD_MD + MD_RAS_END)]
/* Set the new tp */
ldr r9, [r1, #(TD_MD + MD_TP)]
- strt r9, [r3]
+ str r9, [r3]
+ ldr r9, [r1, #(TD_MD + MD_RAS_START)]
+ str r9, [r3, #4]
+ ldr r9, [r1, #(TD_MD + MD_RAS_END)]
+ str r9, [r3, #8]
/* Get the user structure for the new process in r9 */
ldr r9, [r1, #(TD_PCB)]
Modified: head/sys/arm/include/proc.h
==============================================================================
--- head/sys/arm/include/proc.h Thu Feb 12 22:55:39 2009 (r188539)
+++ head/sys/arm/include/proc.h Thu Feb 12 23:23:30 2009 (r188540)
@@ -51,6 +51,8 @@ struct mdthread {
int md_ptrace_instr;
int md_ptrace_addr;
void *md_tp;
+ void *md_ras_start;
+ void *md_ras_end;
};
struct mdproc {
Modified: head/sys/arm/include/sysarch.h
==============================================================================
--- head/sys/arm/include/sysarch.h Thu Feb 12 22:55:39 2009
(r188539)
+++ head/sys/arm/include/sysarch.h Thu Feb 12 23:23:30 2009
(r188540)
@@ -42,6 +42,9 @@
* The ARM_TP_ADDRESS points to a special purpose page, which is used as local
* store for the ARM per-thread data and Restartable Atomic Sequences support.
* Put it just above the "high" vectors' page.
+ * the cpu_switch() code assumes ARM_RAS_START is ARM_TP_ADDRESS + 4, and
+ * ARM_RAS_END is ARM_TP_ADDRESS + 8, so if that ever changes, be sure to
+ * update the cpu_switch() (and cpu_throw()) code as well.
*/
#define ARM_TP_ADDRESS (ARM_VECTORS_HIGH + 0x1000)
#define ARM_RAS_START (ARM_TP_ADDRESS + 4)
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
