From 9f336a53266f43ae1002f4aaad5373944589c828 Mon Sep 17 00:00:00 2001 From: Robin Getz Date: Mon, 29 Oct 2007 18:23:28 +0800 Subject: [PATCH] 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 Signed-off-by: Bryan Wu --- arch/blackfin/kernel/fixed_code.S | 14 ++++++++++++++ arch/blackfin/kernel/setup.c | 2 ++ arch/blackfin/mach-common/entry.S | 2 +- include/asm-blackfin/bfin-global.h | 1 + include/asm-blackfin/fixed_code.h | 4 +++- 5 files changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S index d8b1ebc709..90262691b1 100644 --- a/arch/blackfin/kernel/fixed_code.S +++ b/arch/blackfin/kernel/fixed_code.S @@ -129,4 +129,18 @@ ENTRY(_atomic_xor32) 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 fc22ec8c2f..934234f438 100644 --- a/arch/blackfin/kernel/setup.c +++ b/arch/blackfin/kernel/setup.c @@ -431,6 +431,8 @@ void __init setup_arch(char **cmdline_p) != 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 e3ad580286..1b13fa4709 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -917,7 +917,7 @@ ENTRY(_ex_table) .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 14cb8d3592..0212e180b9 100644 --- a/include/asm-blackfin/bfin-global.h +++ b/include/asm-blackfin/bfin-global.h @@ -80,6 +80,7 @@ extern int atomic_sub32(void); 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 e6df84ee15..37db66c703 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 -- 2.39.5