Changeset 0c39b96 in mainline

Timestamp:

2010-09-03T21:46:30Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

343f2b7e

Parents:

20235a3

Message:

If possible, print stack also with the mips32 trap frame and frames preceding
the trap. Currently, the stack tracer handles well only the most friendly cases,
but it stops tracing when the trap frame was inserted from a leaf-optimised
function. This is partly due to the fact that we are using a simplified
disassembling stack tracer and also because the stack trace printed from
panic_common() completely ignores the information available in istate (which
could be of some help).

Location:

kernel/arch/mips32/src

Files:

• debug/stacktrace.c (modified) (1 diff)
• start.S (modified) (5 diffs)

kernel/arch/mips32/src/debug/stacktrace.c

@@ -180 +180 @@
                                         return false;
                                 /* too big offsets are suspicious */
-                                if (offset > 32 * 4)
+                                if ((size_t) offset > sizeof(istate_t))
                                         return false;
 

kernel/arch/mips32/src/start.S

@@ -91 +91 @@
 
 /*
+ * The fake ABI prologue is never executed and may not be part of the
+ * procedure's body. Instead, it should be immediately preceding the procedure's
+ * body. Its only purpose is to trick the stack trace walker into thinking that
+ * the exception is more or less just a normal function call.
+ */
+.macro FAKE_ABI_PROLOGUE
+        sub $sp, ISTATE_SOFT_SIZE
+        sw $ra, ISTATE_OFFSET_EPC($sp)
+.endm
+
+/*
  * Save registers to space defined by \r
  * We will change status: Disable ERL, EXL, UM, IE
@@ -251 +262 @@
         nop
 
+        FAKE_ABI_PROLOGUE
 exception_handler:
         KERNEL_STACK_TO_K0
@@ -293 +305 @@
  */
 syscall_shortcut:
-        /* we have a lot of space on the stack, with free use */
         mfc0 $t3, $epc
         mfc0 $t2, $status
@@ -339 +350 @@
         eret
 
+        FAKE_ABI_PROLOGUE
 tlb_refill_handler:
         KERNEL_STACK_TO_K0
@@ -352 +364 @@
         eret
 
+        FAKE_ABI_PROLOGUE
 cache_error_handler:
         KERNEL_STACK_TO_K0