From: Suzuki K Poulose Date: Fri, 9 Sep 2016 13:07:15 +0000 (+0100) Subject: arm64: Refactor sysinstr exception handling X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9dbd5bb25c56e35e6b4c34d968689a1ded850924;p=linux-beck.git arm64: Refactor sysinstr exception handling Right now we trap some of the user space data cache operations based on a few Errata (ARM 819472, 826319, 827319 and 824069). We need to trap userspace access to CTR_EL0, if we detect mismatched cache line size. Since both these traps share the EC, refactor the handler a little bit to make it a bit more reader friendly. Cc: Mark Rutland Cc: Will Deacon Cc: Catalin Marinas Acked-by: Andre Przywara Signed-off-by: Suzuki K Poulose Signed-off-by: Will Deacon --- diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index f772e15c4766..9875b326a73e 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -78,6 +78,23 @@ #define ESR_ELx_IL (UL(1) << 25) #define ESR_ELx_ISS_MASK (ESR_ELx_IL - 1) + +/* ISS field definitions shared by different classes */ +#define ESR_ELx_WNR (UL(1) << 6) + +/* Shared ISS field definitions for Data/Instruction aborts */ +#define ESR_ELx_EA (UL(1) << 9) +#define ESR_ELx_S1PTW (UL(1) << 7) + +/* Shared ISS fault status code(IFSC/DFSC) for Data/Instruction aborts */ +#define ESR_ELx_FSC (0x3F) +#define ESR_ELx_FSC_TYPE (0x3C) +#define ESR_ELx_FSC_EXTABT (0x10) +#define ESR_ELx_FSC_ACCESS (0x08) +#define ESR_ELx_FSC_FAULT (0x04) +#define ESR_ELx_FSC_PERM (0x0C) + +/* ISS field definitions for Data Aborts */ #define ESR_ELx_ISV (UL(1) << 24) #define ESR_ELx_SAS_SHIFT (22) #define ESR_ELx_SAS (UL(3) << ESR_ELx_SAS_SHIFT) @@ -86,16 +103,9 @@ #define ESR_ELx_SRT_MASK (UL(0x1F) << ESR_ELx_SRT_SHIFT) #define ESR_ELx_SF (UL(1) << 15) #define ESR_ELx_AR (UL(1) << 14) -#define ESR_ELx_EA (UL(1) << 9) #define ESR_ELx_CM (UL(1) << 8) -#define ESR_ELx_S1PTW (UL(1) << 7) -#define ESR_ELx_WNR (UL(1) << 6) -#define ESR_ELx_FSC (0x3F) -#define ESR_ELx_FSC_TYPE (0x3C) -#define ESR_ELx_FSC_EXTABT (0x10) -#define ESR_ELx_FSC_ACCESS (0x08) -#define ESR_ELx_FSC_FAULT (0x04) -#define ESR_ELx_FSC_PERM (0x0C) + +/* ISS field definitions for exceptions taken in to Hyp */ #define ESR_ELx_CV (UL(1) << 24) #define ESR_ELx_COND_SHIFT (20) #define ESR_ELx_COND_MASK (UL(0xF) << ESR_ELx_COND_SHIFT) @@ -109,6 +119,54 @@ ((ESR_ELx_EC_BRK64 << ESR_ELx_EC_SHIFT) | ESR_ELx_IL | \ ((imm) & 0xffff)) +/* ISS field definitions for System instruction traps */ +#define ESR_ELx_SYS64_ISS_RES0_SHIFT 22 +#define ESR_ELx_SYS64_ISS_RES0_MASK (UL(0x7) << ESR_ELx_SYS64_ISS_RES0_SHIFT) +#define ESR_ELx_SYS64_ISS_DIR_MASK 0x1 +#define ESR_ELx_SYS64_ISS_DIR_READ 0x1 +#define ESR_ELx_SYS64_ISS_DIR_WRITE 0x0 + +#define ESR_ELx_SYS64_ISS_RT_SHIFT 5 +#define ESR_ELx_SYS64_ISS_RT_MASK (UL(0x1f) << ESR_ELx_SYS64_ISS_RT_SHIFT) +#define ESR_ELx_SYS64_ISS_CRM_SHIFT 1 +#define ESR_ELx_SYS64_ISS_CRM_MASK (UL(0xf) << ESR_ELx_SYS64_ISS_CRM_SHIFT) +#define ESR_ELx_SYS64_ISS_CRN_SHIFT 10 +#define ESR_ELx_SYS64_ISS_CRN_MASK (UL(0xf) << ESR_ELx_SYS64_ISS_CRN_SHIFT) +#define ESR_ELx_SYS64_ISS_OP1_SHIFT 14 +#define ESR_ELx_SYS64_ISS_OP1_MASK (UL(0x7) << ESR_ELx_SYS64_ISS_OP1_SHIFT) +#define ESR_ELx_SYS64_ISS_OP2_SHIFT 17 +#define ESR_ELx_SYS64_ISS_OP2_MASK (UL(0x7) << ESR_ELx_SYS64_ISS_OP2_SHIFT) +#define ESR_ELx_SYS64_ISS_OP0_SHIFT 20 +#define ESR_ELx_SYS64_ISS_OP0_MASK (UL(0x3) << ESR_ELx_SYS64_ISS_OP0_SHIFT) +#define ESR_ELx_SYS64_ISS_SYS_MASK (ESR_ELx_SYS64_ISS_OP0_MASK | \ + ESR_ELx_SYS64_ISS_OP1_MASK | \ + ESR_ELx_SYS64_ISS_OP2_MASK | \ + ESR_ELx_SYS64_ISS_CRN_MASK | \ + ESR_ELx_SYS64_ISS_CRM_MASK) +#define ESR_ELx_SYS64_ISS_SYS_VAL(op0, op1, op2, crn, crm) \ + (((op0) << ESR_ELx_SYS64_ISS_OP0_SHIFT) | \ + ((op1) << ESR_ELx_SYS64_ISS_OP1_SHIFT) | \ + ((op2) << ESR_ELx_SYS64_ISS_OP2_SHIFT) | \ + ((crn) << ESR_ELx_SYS64_ISS_CRN_SHIFT) | \ + ((crm) << ESR_ELx_SYS64_ISS_CRM_SHIFT)) +/* + * User space cache operations have the following sysreg encoding + * in System instructions. + * op0=1, op1=3, op2=1, crn=7, crm={ 5, 10, 11, 14 }, WRITE (L=0) + */ +#define ESR_ELx_SYS64_ISS_CRM_DC_CIVAC 14 +#define ESR_ELx_SYS64_ISS_CRM_DC_CVAU 11 +#define ESR_ELx_SYS64_ISS_CRM_DC_CVAC 10 +#define ESR_ELx_SYS64_ISS_CRM_IC_IVAU 5 + +#define ESR_ELx_SYS64_ISS_EL0_CACHE_OP_MASK (ESR_ELx_SYS64_ISS_OP0_MASK | \ + ESR_ELx_SYS64_ISS_OP1_MASK | \ + ESR_ELx_SYS64_ISS_OP2_MASK | \ + ESR_ELx_SYS64_ISS_CRN_MASK | \ + ESR_ELx_SYS64_ISS_DIR_MASK) +#define ESR_ELx_SYS64_ISS_EL0_CACHE_OP_VAL \ + (ESR_ELx_SYS64_ISS_SYS_VAL(1, 3, 1, 7, 0) | \ + ESR_ELx_SYS64_ISS_DIR_WRITE) #ifndef __ASSEMBLY__ #include diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index e04f83873af7..224f64eddd93 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -447,36 +447,29 @@ void cpu_enable_cache_maint_trap(void *__unused) : "=r" (res) \ : "r" (address), "i" (-EFAULT) ) -asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) +static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs) { unsigned long address; - int ret; + int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; + int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT; + int ret = 0; - /* if this is a write with: Op0=1, Op2=1, Op1=3, CRn=7 */ - if ((esr & 0x01fffc01) == 0x0012dc00) { - int rt = (esr >> 5) & 0x1f; - int crm = (esr >> 1) & 0x0f; + address = (rt == 31) ? 0 : regs->regs[rt]; - address = (rt == 31) ? 0 : regs->regs[rt]; - - switch (crm) { - case 11: /* DC CVAU, gets promoted */ - __user_cache_maint("dc civac", address, ret); - break; - case 10: /* DC CVAC, gets promoted */ - __user_cache_maint("dc civac", address, ret); - break; - case 14: /* DC CIVAC */ - __user_cache_maint("dc civac", address, ret); - break; - case 5: /* IC IVAU */ - __user_cache_maint("ic ivau", address, ret); - break; - default: - force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); - return; - } - } else { + switch (crm) { + case ESR_ELx_SYS64_ISS_CRM_DC_CVAU: /* DC CVAU, gets promoted */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_DC_CVAC: /* DC CVAC, gets promoted */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC: /* DC CIVAC */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_IC_IVAU: /* IC IVAU */ + __user_cache_maint("ic ivau", address, ret); + break; + default: force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); return; } @@ -487,6 +480,34 @@ asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) regs->pc += 4; } +struct sys64_hook { + unsigned int esr_mask; + unsigned int esr_val; + void (*handler)(unsigned int esr, struct pt_regs *regs); +}; + +static struct sys64_hook sys64_hooks[] = { + { + .esr_mask = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_MASK, + .esr_val = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_VAL, + .handler = user_cache_maint_handler, + }, + {}, +}; + +asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) +{ + struct sys64_hook *hook; + + for (hook = sys64_hooks; hook->handler; hook++) + if ((hook->esr_mask & esr) == hook->esr_val) { + hook->handler(esr, regs); + return; + } + + force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); +} + long compat_arm_syscall(struct pt_regs *regs); asmlinkage long do_ni_syscall(struct pt_regs *regs)