diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S index d8b1ebc7099684d1dd46fea05cf4d94186fcd7df..90262691b11a299993108608e0ad63d19feb0a63 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 fc22ec8c2f47ef397257cff3f2aacfb9591aaece..934234f438390d8ddfb11c664528bfe984cc297d 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 e3ad5802868a2489865a761ae32b824b6a87ecc4..1b13fa470977e8d0c13aa3ba722f009f47556445 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 14cb8d35924e7c3505126057d3f9648d927435fe..0212e180b90e327d1a82c9c68145c551ab757843 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 e6df84ee1557893f4e930b4fb4a3f3ac556fd2f6..37db66c7030d12e91eabc205ed9ea4059195515a 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