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authorMagnus Lång <[email protected]>2016-04-12 13:08:02 +0200
committerMagnus Lång <[email protected]>2016-06-30 12:01:57 +0200
commit1dd81185dfb2fd6ac30b6eb44c905128c8958cb4 (patch)
tree4455256dd37472db1188f4c0dce79db658a0e58e /erts/emulator/hipe/hipe_arm_asm.m4
parentc2157dc06a8c997c207dd82cd6fa11dbcb508f11 (diff)
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hipe: Add assertion for gc in bif without wrapper
An easy source of tricky bugs is to start calling the garbage collector from a built-in function without adding that bif to hipe_bif_list.m4. With this change we, in the debug build, keep track of whether the canonical stack and heap pointers are stored in the PCB or in registers/stack, allowing us to catch this class of mistakes with an assertion.
Diffstat (limited to 'erts/emulator/hipe/hipe_arm_asm.m4')
-rw-r--r--erts/emulator/hipe/hipe_arm_asm.m432
1 files changed, 27 insertions, 5 deletions
diff --git a/erts/emulator/hipe/hipe_arm_asm.m4 b/erts/emulator/hipe/hipe_arm_asm.m4
index ae9ec752bb..68a6faa70b 100644
--- a/erts/emulator/hipe/hipe_arm_asm.m4
+++ b/erts/emulator/hipe/hipe_arm_asm.m4
@@ -48,6 +48,24 @@ define(NR_ARG_REGS,3)dnl admissible values are 0 to 6, inclusive
`#define TEMP_LR r8'
/*
+ * Debugging macros
+ *
+ * Keeps track of whether context has been saved in the debug build, allowing us
+ * to detect when the garbage collector is called when it shouldn't.
+ */
+`#ifdef DEBUG
+# define SET_GC_UNSAFE(SCRATCH) \
+ mov SCRATCH, #1; \
+ str SCRATCH, [P, #P_GCUNSAFE]
+# define SET_GC_SAFE(SCRATCH) \
+ mov SCRATCH, #0; \
+ str SCRATCH, [P, #P_GCUNSAFE]
+#else
+# define SET_GC_UNSAFE(SCRATCH)
+# define SET_GC_SAFE(SCRATCH)
+#endif'
+
+/*
* Context switching macros.
*
* RESTORE_CONTEXT and RESTORE_CONTEXT_QUICK do not affect
@@ -59,12 +77,14 @@ define(NR_ARG_REGS,3)dnl admissible values are 0 to 6, inclusive
`#define RESTORE_CONTEXT_QUICK \
mov lr, TEMP_LR'
-`#define SAVE_CACHED_STATE \
- str HP, [P, #P_HP]; \
- str NSP, [P, #P_NSP]'
+`#define SAVE_CACHED_STATE \
+ str HP, [P, #P_HP]; \
+ str NSP, [P, #P_NSP]; \
+ SET_GC_SAFE(HP)'
-`#define RESTORE_CACHED_STATE \
- ldr HP, [P, #P_HP]; \
+`#define RESTORE_CACHED_STATE \
+ SET_GC_UNSAFE(HP); \
+ ldr HP, [P, #P_HP]; \
ldr NSP, [P, #P_NSP]'
`#define SAVE_CONTEXT_BIF \
@@ -75,12 +95,14 @@ define(NR_ARG_REGS,3)dnl admissible values are 0 to 6, inclusive
ldr HP, [P, #P_HP]'
`#define SAVE_CONTEXT_GC \
+ SET_GC_SAFE(TEMP_LR); \
mov TEMP_LR, lr; \
str lr, [P, #P_NRA]; \
str NSP, [P, #P_NSP]; \
str HP, [P, #P_HP]'
`#define RESTORE_CONTEXT_GC \
+ SET_GC_UNSAFE(HP); \
ldr HP, [P, #P_HP]'
/*