Align fake data in the same page offsets as those in the bugreport.

Sometimes the crash in the JIT'ed code is due to CPU bugs which are sensitive
to placement of the code.

Change-Id: I017ec3620f8172e2fac9e7abfa07f76b65db2306

1 files changed, 28 insertions, 6 deletions

diff --git a/tools/gdbjithelper/gdbjithelper.c b/tools/gdbjithelper/gdbjithelper.c
index d0f9ce385..862fcae2f 100644
--- a/tools/gdbjithelper/gdbjithelper.c
+++ b/tools/gdbjithelper/gdbjithelper.c
@@ -16,6 +16,11 @@
 
 #include <unistd.h>
 #include <stdio.h>
+#include <malloc.h>
+#include <string.h>
+
+/* Currently debuggerd dumps 20 words each around PC and LR */
+#define NUM_DUMPED_WORDS 20
 
 volatile int done;
 
@@ -63,22 +68,39 @@ int codeLR[] = {
     0x4284aa7a, 0xf927f7b7, 0x40112268, 0x419da7f8,
 };
 
-void dumpCode()
+/* For example: 463ba1e4 & 0xfff */
+#define START_PC_PAGE_OFFSET 0x1e4
+
+/* For example: 463ba1a8 & 0xfff */
+#define START_LR_PAGE_OFFSET 0x1a8
+
+/* Each points to a two-page buffer */
+char *codePCCache, *codeLRCache;
+
+void dumpCode(int *pc, int *lr)
 {
     unsigned int i;
 
-    for (i = 0; i < sizeof(codePC)/sizeof(int); i++) {
-        printf("codePC[%d]: %#x\n", i, codePC[i]);
+    for (i = 0; i < NUM_DUMPED_WORDS; i++) {
+        printf("%p codePC[%d]: %#010x\n", pc + i, i, pc[i]);
     }
 
-    for (i = 0; i < sizeof(codeLR)/sizeof(int); i++) {
-        printf("codeLR[%d]: %#x\n", i, codeLR[i]);
+    for (i = 0; i < NUM_DUMPED_WORDS; i++) {
+        printf("%p codeLR[%d]: %#010x\n", lr + i, i, lr[i]);
     }
 }
 
 int main()
 {
-    dumpCode();
+    codePCCache = memalign(4096, 8192);
+    codeLRCache = memalign(4096, 8192);
+
+    memcpy(codePCCache + START_PC_PAGE_OFFSET, codePC, 4 * NUM_DUMPED_WORDS);
+    memcpy(codeLRCache + START_LR_PAGE_OFFSET, codeLR, 4 * NUM_DUMPED_WORDS);
+
+    dumpCode((int *) (codePCCache + START_PC_PAGE_OFFSET),
+             (int *) (codeLRCache + START_LR_PAGE_OFFSET));
+
     while (!done) {
         sleep(1000);
     }