Blackfin arch: ensure that speculative loads of bad pointers don't cause us to do bad things.
Fix/change formatting of a few more things.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S
index d8b1ebc7..9026269 100644
--- a/arch/blackfin/kernel/fixed_code.S
+++ b/arch/blackfin/kernel/fixed_code.S
@@ -129,4 +129,18 @@
rts;
ENDPROC (_atomic_ior32)
+.align 16
+ /*
+ * safe_user_instruction
+ * Four NOPS are enough to allow the pipeline to speculativily load
+ * execute anything it wants. After that, things have gone bad, and
+ * we are stuck - so panic. Since we might be in user space, we can't
+ * call panic, so just cause a unhandled exception, this should cause
+ * a dump of the trace buffer so we can tell were we are, and a reboot
+ */
+ENTRY(_safe_user_instruction)
+ NOP; NOP; NOP; NOP;
+ EXCPT 0x4;
+ENDPROC(_safe_user_instruction)
+
ENTRY(_fixed_code_end)
diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index fc22ec8c..934234f 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -431,6 +431,8 @@
!= ATOMIC_AND32 - FIXED_CODE_START);
BUG_ON((char *)&atomic_xor32 - (char *)&fixed_code_start
!= ATOMIC_XOR32 - FIXED_CODE_START);
+ BUG_ON((char *)&safe_user_instruction - (char *)&fixed_code_start
+ != SAFE_USER_INSTRUCTION - FIXED_CODE_START);
init_exception_vectors();
bf53x_cache_init();
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index e3ad580..1b13fa47 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -917,7 +917,7 @@
.long _ex_soft_bp /* 0x01 - User Defined - Software breakpoint */
.long _ex_replaceable /* 0x02 - User Defined */
.long _ex_trap_c /* 0x03 - User Defined - userspace stack overflow */
- .long _ex_replaceable /* 0x04 - User Defined */
+ .long _ex_trap_c /* 0x04 - User Defined - dump trace buffer */
.long _ex_replaceable /* 0x05 - User Defined */
.long _ex_replaceable /* 0x06 - User Defined */
.long _ex_replaceable /* 0x07 - User Defined */
diff --git a/include/asm-blackfin/bfin-global.h b/include/asm-blackfin/bfin-global.h
index 14cb8d3..0212e18 100644
--- a/include/asm-blackfin/bfin-global.h
+++ b/include/asm-blackfin/bfin-global.h
@@ -80,6 +80,7 @@
extern int atomic_ior32(void);
extern int atomic_and32(void);
extern int atomic_xor32(void);
+extern void safe_user_instruction(void);
extern void sigreturn_stub(void);
extern void *l1_data_A_sram_alloc(size_t);
diff --git a/include/asm-blackfin/fixed_code.h b/include/asm-blackfin/fixed_code.h
index e6df84e..37db66c 100644
--- a/include/asm-blackfin/fixed_code.h
+++ b/include/asm-blackfin/fixed_code.h
@@ -17,4 +17,6 @@
#define ATOMIC_SEQS_END 0x480
-#define FIXED_CODE_END 0x480
+#define SAFE_USER_INSTRUCTION 0x480
+
+#define FIXED_CODE_END 0x490