diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h index 62358d3ca0a821..e7f9961c53b2df 100644 --- a/arch/arm/include/asm/hw_breakpoint.h +++ b/arch/arm/include/asm/hw_breakpoint.h @@ -84,6 +84,7 @@ static inline void decode_ctrl_reg(u32 reg, #define ARM_DSCR_MOE(x) ((x >> 2) & 0xf) #define ARM_ENTRY_BREAKPOINT 0x1 #define ARM_ENTRY_ASYNC_WATCHPOINT 0x2 +#define ARM_ENTRY_CFI_BREAKPOINT 0x3 #define ARM_ENTRY_SYNC_WATCHPOINT 0xa /* DSCR monitor/halting bits. */ diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index dc0fb7a8137150..93f9034e4e72de 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -903,6 +904,37 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs) watchpoint_single_step_handler(addr); } +#ifdef CONFIG_CFI_CLANG +static void hw_breakpoint_cfi_handler(struct pt_regs *regs) +{ + /* + * TODO: implementing target and type to pass to CFI using the more + * elaborate report_cfi_failure() requires compiler work. To be able + * to properly extract target information the compiler needs to + * emit a stable instructions sequence for the CFI checks so we can + * decode the instructions preceding the trap and figure out which + * registers were used. + */ + + switch (report_cfi_failure_noaddr(regs, instruction_pointer(regs))) { + case BUG_TRAP_TYPE_BUG: + die("Oops - CFI", regs, 0); + break; + case BUG_TRAP_TYPE_WARN: + /* Skip the breaking instruction */ + instruction_pointer(regs) += 4; + break; + default: + die("Unknown CFI error", regs, 0); + break; + } +} +#else +static void hw_breakpoint_cfi_handler(struct pt_regs *regs) +{ +} +#endif + /* * Called from either the Data Abort Handler [watchpoint] or the * Prefetch Abort Handler [breakpoint] with interrupts disabled. @@ -932,6 +964,9 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr, case ARM_ENTRY_SYNC_WATCHPOINT: watchpoint_handler(addr, fsr, regs); break; + case ARM_ENTRY_CFI_BREAKPOINT: + hw_breakpoint_cfi_handler(regs); + break; default: ret = 1; /* Unhandled fault. */ }