diff options
| -rw-r--r-- | arch/riscv/Kconfig | 9 | ||||
| -rw-r--r-- | arch/riscv/include/asm/cpufeature.h | 18 | ||||
| -rw-r--r-- | arch/riscv/include/asm/entry-common.h | 14 | ||||
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 9 | ||||
| -rw-r--r-- | arch/riscv/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/riscv/kernel/cpufeature.c | 6 | ||||
| -rw-r--r-- | arch/riscv/kernel/fpu.S | 121 | ||||
| -rw-r--r-- | arch/riscv/kernel/process.c | 18 | ||||
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 2 | ||||
| -rw-r--r-- | arch/riscv/kernel/traps.c | 9 | ||||
| -rw-r--r-- | arch/riscv/kernel/traps_misaligned.c | 375 |
11 files changed, 524 insertions, 59 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index ad96f9c1fc7f..3f77530180b9 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -643,6 +643,15 @@ config THREAD_SIZE_ORDER Specify the Pages of thread stack size (from 4KB to 64KB), which also affects irq stack size, which is equal to thread stack size. +config RISCV_MISALIGNED + bool "Support misaligned load/store traps for kernel and userspace" + select SYSCTL_ARCH_UNALIGN_ALLOW + default y + help + Say Y here if you want the kernel to embed support for misaligned + load/store for both kernel and userspace. When disable, misaligned + accesses will generate SIGBUS in userspace and panic in kernel. + endmenu # "Platform type" menu "Kernel features" diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index 13b7d35648a9..7f1e46a9d445 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -33,4 +33,22 @@ extern struct riscv_isainfo hart_isa[NR_CPUS]; void check_unaligned_access(int cpu); void riscv_user_isa_enable(void); +#ifdef CONFIG_RISCV_MISALIGNED +bool unaligned_ctl_available(void); +bool check_unaligned_access_emulated(int cpu); +void unaligned_emulation_finish(void); +#else +static inline bool unaligned_ctl_available(void) +{ + return false; +} + +static inline bool check_unaligned_access_emulated(int cpu) +{ + return false; +} + +static inline void unaligned_emulation_finish(void) {} +#endif + #endif diff --git a/arch/riscv/include/asm/entry-common.h b/arch/riscv/include/asm/entry-common.h index 6e4dee49d84b..7ab5e34318c8 100644 --- a/arch/riscv/include/asm/entry-common.h +++ b/arch/riscv/include/asm/entry-common.h @@ -8,4 +8,18 @@ void handle_page_fault(struct pt_regs *regs); void handle_break(struct pt_regs *regs); +#ifdef CONFIG_RISCV_MISALIGNED +int handle_misaligned_load(struct pt_regs *regs); +int handle_misaligned_store(struct pt_regs *regs); +#else +static inline int handle_misaligned_load(struct pt_regs *regs) +{ + return -1; +} +static inline int handle_misaligned_store(struct pt_regs *regs) +{ + return -1; +} +#endif + #endif /* _ASM_RISCV_ENTRY_COMMON_H */ diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 3e23e1786d05..adbe520d07c5 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -8,6 +8,7 @@ #include <linux/const.h> #include <linux/cache.h> +#include <linux/prctl.h> #include <vdso/processor.h> @@ -82,6 +83,7 @@ struct thread_struct { unsigned long bad_cause; unsigned long vstate_ctrl; struct __riscv_v_ext_state vstate; + unsigned long align_ctl; }; /* Whitelist the fstate from the task_struct for hardened usercopy */ @@ -94,6 +96,7 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset, #define INIT_THREAD { \ .sp = sizeof(init_stack) + (long)&init_stack, \ + .align_ctl = PR_UNALIGN_NOPRINT, \ } #define task_pt_regs(tsk) \ @@ -134,6 +137,12 @@ extern long riscv_v_vstate_ctrl_set_current(unsigned long arg); extern long riscv_v_vstate_ctrl_get_current(void); #endif /* CONFIG_RISCV_ISA_V */ +extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr); +extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val); + +#define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr)) +#define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val)) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_PROCESSOR_H */ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 95cf25d48405..0d874fb24b51 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -59,7 +59,7 @@ obj-y += patch.o obj-y += probes/ obj-$(CONFIG_MMU) += vdso.o vdso/ -obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o +obj-$(CONFIG_RISCV_MISALIGNED) += traps_misaligned.o obj-$(CONFIG_FPU) += fpu.o obj-$(CONFIG_RISCV_ISA_V) += vector.o obj-$(CONFIG_SMP) += smpboot.o diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 9e0d375a40f6..970a71422bee 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -569,6 +569,9 @@ void check_unaligned_access(int cpu) void *src; long speed = RISCV_HWPROBE_MISALIGNED_SLOW; + if (check_unaligned_access_emulated(cpu)) + return; + page = alloc_pages(GFP_NOWAIT, get_order(MISALIGNED_BUFFER_SIZE)); if (!page) { pr_warn("Can't alloc pages to measure memcpy performance"); @@ -646,9 +649,10 @@ out: __free_pages(page, get_order(MISALIGNED_BUFFER_SIZE)); } -static int check_unaligned_access_boot_cpu(void) +static int __init check_unaligned_access_boot_cpu(void) { check_unaligned_access(0); + unaligned_emulation_finish(); return 0; } diff --git a/arch/riscv/kernel/fpu.S b/arch/riscv/kernel/fpu.S index dd2205473de7..5dd3161a4dac 100644 --- a/arch/riscv/kernel/fpu.S +++ b/arch/riscv/kernel/fpu.S @@ -104,3 +104,124 @@ ENTRY(__fstate_restore) csrc CSR_STATUS, t1 ret ENDPROC(__fstate_restore) + +#define get_f32(which) fmv.x.s a0, which; j 2f +#define put_f32(which) fmv.s.x which, a1; j 2f +#if __riscv_xlen == 64 +# define get_f64(which) fmv.x.d a0, which; j 2f +# define put_f64(which) fmv.d.x which, a1; j 2f +#else +# define get_f64(which) fsd which, 0(a1); j 2f +# define put_f64(which) fld which, 0(a1); j 2f +#endif + +.macro fp_access_prologue + /* + * Compute jump offset to store the correct FP register since we don't + * have indirect FP register access + */ + sll t0, a0, 3 + la t2, 1f + add t0, t0, t2 + li t1, SR_FS + csrs CSR_STATUS, t1 + jr t0 +1: +.endm + +.macro fp_access_epilogue +2: + csrc CSR_STATUS, t1 + ret +.endm + +#define fp_access_body(__access_func) \ + __access_func(f0); \ + __access_func(f1); \ + __access_func(f2); \ + __access_func(f3); \ + __access_func(f4); \ + __access_func(f5); \ + __access_func(f6); \ + __access_func(f7); \ + __access_func(f8); \ + __access_func(f9); \ + __access_func(f10); \ + __access_func(f11); \ + __access_func(f12); \ + __access_func(f13); \ + __access_func(f14); \ + __access_func(f15); \ + __access_func(f16); \ + __access_func(f17); \ + __access_func(f18); \ + __access_func(f19); \ + __access_func(f20); \ + __access_func(f21); \ + __access_func(f22); \ + __access_func(f23); \ + __access_func(f24); \ + __access_func(f25); \ + __access_func(f26); \ + __access_func(f27); \ + __access_func(f28); \ + __access_func(f29); \ + __access_func(f30); \ + __access_func(f31) + + +#ifdef CONFIG_RISCV_MISALIGNED + +/* + * Disable compressed instructions set to keep a constant offset between FP + * load/store/move instructions + */ +.option norvc +/* + * put_f32_reg - Set a FP register from a register containing the value + * a0 = FP register index to be set + * a1 = value to be loaded in the FP register + */ +SYM_FUNC_START(put_f32_reg) + fp_access_prologue + fp_access_body(put_f32) + fp_access_epilogue +SYM_FUNC_END(put_f32_reg) + +/* + * get_f32_reg - Get a FP register value and return it + * a0 = FP register index to be retrieved + */ +SYM_FUNC_START(get_f32_reg) + fp_access_prologue + fp_access_body(get_f32) + fp_access_epilogue +SYM_FUNC_END(get_f32_reg) + +/* + * put_f64_reg - Set a 64 bits FP register from a value or a pointer. + * a0 = FP register index to be set + * a1 = value/pointer to be loaded in the FP register (when xlen == 32 bits, we + * load the value to a pointer). + */ +SYM_FUNC_START(put_f64_reg) + fp_access_prologue + fp_access_body(put_f64) + fp_access_epilogue +SYM_FUNC_END(put_f64_reg) + +/* + * put_f64_reg - Get a 64 bits FP register value and returned it or store it to + * a pointer. + * a0 = FP register index to be retrieved + * a1 = If xlen == 32, pointer which should be loaded with the FP register value + * or unused if xlen == 64. In which case the FP register value is returned + * through a0 + */ +SYM_FUNC_START(get_f64_reg) + fp_access_prologue + fp_access_body(get_f64) + fp_access_epilogue +SYM_FUNC_END(get_f64_reg) + +#endif /* CONFIG_RISCV_MISALIGNED */ diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index e32d737e039f..4f21d970a129 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -25,6 +25,7 @@ #include <asm/thread_info.h> #include <asm/cpuidle.h> #include <asm/vector.h> +#include <asm/cpufeature.h> register unsigned long gp_in_global __asm__("gp"); @@ -41,6 +42,23 @@ void arch_cpu_idle(void) cpu_do_idle(); } +int set_unalign_ctl(struct task_struct *tsk, unsigned int val) +{ + if (!unaligned_ctl_available()) + return -EINVAL; + + tsk->thread.align_ctl = val; + return 0; +} + +int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) +{ + if (!unaligned_ctl_available()) + return -EINVAL; + + return put_user(tsk->thread.align_ctl, (unsigned long __user *)adr); +} + void __show_regs(struct pt_regs *regs) { show_regs_print_info(KERN_DEFAULT); diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index d1b0a6fc3adf..d69c628c24f4 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -247,8 +247,8 @@ asmlinkage __visible void smp_callin(void) riscv_ipi_enable(); numa_add_cpu(curr_cpuid); - set_cpu_online(curr_cpuid, 1); check_unaligned_access(curr_cpuid); + set_cpu_online(curr_cpuid, 1); if (has_vector()) { if (riscv_v_setup_vsize()) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index cda6dcdb0376..8895c8197519 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -179,14 +179,6 @@ asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *re DO_ERROR_INFO(do_trap_load_fault, SIGSEGV, SEGV_ACCERR, "load access fault"); -#ifndef CONFIG_RISCV_M_MODE -DO_ERROR_INFO(do_trap_load_misaligned, - SIGBUS, BUS_ADRALN, "Oops - load address misaligned"); -DO_ERROR_INFO(do_trap_store_misaligned, - SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned"); -#else -int handle_misaligned_load(struct pt_regs *regs); -int handle_misaligned_store(struct pt_regs *regs); asmlinkage __visible __trap_section void do_trap_load_misaligned(struct pt_regs *regs) { @@ -229,7 +221,6 @@ asmlinkage __visible __trap_section void do_trap_store_misaligned(struct pt_regs irqentry_nmi_exit(regs, state); } } -#endif DO_ERROR_INFO(do_trap_store_fault, SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault"); DO_ERROR_INFO(do_trap_ecall_s, diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 378f5b151443..bba301b5194d 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -6,12 +6,16 @@ #include <linux/init.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/perf_event.h> #include <linux/irq.h> #include <linux/stringify.h> #include <asm/processor.h> #include <asm/ptrace.h> #include <asm/csr.h> +#include <asm/entry-common.h> +#include <asm/hwprobe.h> +#include <asm/cpufeature.h> #define INSN_MATCH_LB 0x3 #define INSN_MASK_LB 0x707f @@ -151,53 +155,134 @@ #define PRECISION_S 0 #define PRECISION_D 1 -#define DECLARE_UNPRIVILEGED_LOAD_FUNCTION(type, insn) \ -static inline type load_##type(const type *addr) \ -{ \ - type val; \ - asm (#insn " %0, %1" \ - : "=&r" (val) : "m" (*addr)); \ - return val; \ +#ifdef CONFIG_FPU + +#define FP_GET_RD(insn) (insn >> 7 & 0x1F) + +extern void put_f32_reg(unsigned long fp_reg, unsigned long value); + +static int set_f32_rd(unsigned long insn, struct pt_regs *regs, + unsigned long val) +{ + unsigned long fp_reg = FP_GET_RD(insn); + + put_f32_reg(fp_reg, val); + regs->status |= SR_FS_DIRTY; + + return 0; } -#define DECLARE_UNPRIVILEGED_STORE_FUNCTION(type, insn) \ -static inline void store_##type(type *addr, type val) \ -{ \ - asm volatile (#insn " %0, %1\n" \ - : : "r" (val), "m" (*addr)); \ +extern void put_f64_reg(unsigned long fp_reg, unsigned long value); + +static int set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val) +{ + unsigned long fp_reg = FP_GET_RD(insn); + unsigned long value; + +#if __riscv_xlen == 32 + value = (unsigned long) &val; +#else + value = val; +#endif + put_f64_reg(fp_reg, value); + regs->status |= SR_FS_DIRTY; + + return 0; } -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u8, lbu) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u16, lhu) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s8, lb) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s16, lh) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s32, lw) -DECLARE_UNPRIVILEGED_STORE_FUNCTION(u8, sb) -DECLARE_UNPRIVILEGED_STORE_FUNCTION(u16, sh) -DECLARE_UNPRIVILEGED_STORE_FUNCTION(u32, sw) -#if defined(CONFIG_64BIT) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u32, lwu) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u64, ld) -DECLARE_UNPRIVILEGED_STORE_FUNCTION(u64, sd) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(ulong, ld) +#if __riscv_xlen == 32 +extern void get_f64_reg(unsigned long fp_reg, u64 *value); + +static u64 get_f64_rs(unsigned long insn, u8 fp_reg_offset, + struct pt_regs *regs) +{ + unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; + u64 val; + + get_f64_reg(fp_reg, &val); + regs->status |= SR_FS_DIRTY; + + return val; +} #else -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u32, lw) -DECLARE_UNPRIVILEGED_LOAD_FUNCTION(ulong, lw) -static inline u64 load_u64(const u64 *addr) +extern unsigned long get_f64_reg(unsigned long fp_reg); + +static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset, + struct pt_regs *regs) { - return load_u32((u32 *)addr) - + ((u64)load_u32((u32 *)addr + 1) << 32); + unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; + unsigned long val; + + val = get_f64_reg(fp_reg); + regs->status |= SR_FS_DIRTY; + + return val; } -static inline void store_u64(u64 *addr, u64 val) +#endif + +extern unsigned long get_f32_reg(unsigned long fp_reg); + +static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset, + struct pt_regs *regs) { - store_u32((u32 *)addr, val); - store_u32((u32 *)addr + 1, val >> 32); + unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; + unsigned long val; + + val = get_f32_reg(fp_reg); + regs->status |= SR_FS_DIRTY; + + return val; } + +#else /* CONFIG_FPU */ +static void set_f32_rd(unsigned long insn, struct pt_regs *regs, + unsigned long val) {} + +static void set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val) {} + +static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset, + struct pt_regs *regs) +{ + return 0; +} + +static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset, + struct pt_regs *regs) +{ + return 0; +} + #endif -static inline ulong get_insn(ulong mepc) +#define GET_F64_RS2(insn, regs) (get_f64_rs(insn, 20, regs)) +#define GET_F64_RS2C(insn, regs) (get_f64_rs(insn, 2, regs)) +#define GET_F64_RS2S(insn, regs) (get_f64_rs(RVC_RS2S(insn), 0, regs)) + +#define GET_F32_RS2(insn, regs) (get_f32_rs(insn, 20, regs)) +#define GET_F32_RS2C(insn, regs) (get_f32_rs(insn, 2, regs)) +#define GET_F32_RS2S(insn, regs) (get_f32_rs(RVC_RS2S(insn), 0, regs)) + +#ifdef CONFIG_RISCV_M_MODE +static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val) +{ + u8 val; + + asm volatile("lbu %0, %1" : "=&r" (val) : "m" (*addr)); + *r_val = val; + + return 0; +} + +static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val) +{ + asm volatile ("sb %0, %1\n" : : "r" (val), "m" (*addr)); + + return 0; +} + +static inline int get_insn(struct pt_regs *regs, ulong mepc, ulong *r_insn) { register ulong __mepc asm ("a2") = mepc; ulong val, rvc_mask = 3, tmp; @@ -226,23 +311,119 @@ static inline ulong get_insn(ulong mepc) : [addr] "r" (__mepc), [rvc_mask] "r" (rvc_mask), [xlen_minus_16] "i" (XLEN_MINUS_16)); - return val; + *r_insn = val; + + return 0; +} +#else +static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val) +{ + if (user_mode(regs)) { + return __get_user(*r_val, addr); + } else { + *r_val = *addr; + return 0; + } +} + +static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val) +{ + if (user_mode(regs)) { + return __put_user(val, addr); + } else { + *addr = val; + return 0; + } } +#define __read_insn(regs, insn, insn_addr) \ +({ \ + int __ret; \ + \ + if (user_mode(regs)) { \ + __ret = __get_user(insn, insn_addr); \ + } else { \ + insn = *insn_addr; \ + __ret = 0; \ + } \ + \ + __ret; \ +}) + +static inline int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn) +{ + ulong insn = 0; + + if (epc & 0x2) { + ulong tmp = 0; + u16 __user *insn_addr = (u16 __user *)epc; + + if (__read_insn(regs, insn, insn_addr)) + return -EFAULT; + /* __get_user() uses regular "lw" which sign extend the loaded + * value make sure to clear higher order bits in case we "or" it + * below with the upper 16 bits half. + */ + insn &= GENMASK(15, 0); + if ((insn & __INSN_LENGTH_MASK) != __INSN_LENGTH_32) { + *r_insn = insn; + return 0; + } + insn_addr++; + if (__read_insn(regs, tmp, insn_addr)) + return -EFAULT; + *r_insn = (tmp << 16) | insn; + + return 0; + } else { + u32 __user *insn_addr = (u32 __user *)epc; + + if (__read_insn(regs, insn, insn_addr)) + return -EFAULT; + if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) { + *r_insn = insn; + return 0; + } + insn &= GENMASK(15, 0); + *r_insn = insn; + + return 0; + } +} +#endif + union reg_data { u8 data_bytes[8]; ulong data_ulong; u64 data_u64; }; +static bool unaligned_ctl __read_mostly; + +/* sysctl hooks */ +int unaligned_enabled __read_mostly = 1; /* Enabled by default */ + int handle_misaligned_load(struct pt_regs *regs) { union reg_data val; unsigned long epc = regs->epc; - unsigned long insn = get_insn(epc); - unsigned long addr = csr_read(mtval); + unsigned long insn; + unsigned long addr = regs->badaddr; int i, fp = 0, shift = 0, len = 0; + perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); + + *this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_EMULATED; + + if (!unaligned_enabled) + return -1; + + if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS)) + return -1; + + if (get_insn(regs, epc, &insn)) + return -1; + regs->epc = 0; if ((insn & INSN_MASK_LW) == INSN_MATCH_LW) { @@ -305,13 +486,21 @@ int handle_misaligned_load(struct pt_regs *regs) return -1; } + if (!IS_ENABLED(CONFIG_FPU) && fp) + return -EOPNOTSUPP; + val.data_u64 = 0; - for (i = 0; i < len; i++) - val.data_bytes[i] = load_u8((void *)(addr + i)); + for (i = 0; i < len; i++) { + if (load_u8(regs, (void *)(addr + i), &val.data_bytes[i])) + return -1; + } - if (fp) - return -1; - SET_RD(insn, regs, val.data_ulong << shift >> shift); + if (!fp) + SET_RD(insn, regs, val.data_ulong << shift >> shift); + else if (len == 8) + set_f64_rd(insn, regs, val.data_u64); + else + set_f32_rd(insn, regs, val.data_ulong); regs->epc = epc + INSN_LEN(insn); @@ -322,9 +511,20 @@ int handle_misaligned_store(struct pt_regs *regs) { union reg_data val; unsigned long epc = regs->epc; - unsigned long insn = get_insn(epc); - unsigned long addr = csr_read(mtval); - int i, len = 0; + unsigned long insn; + unsigned long addr = regs->badaddr; + int i, len = 0, fp = 0; + + perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); + + if (!unaligned_enabled) + return -1; + + if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS)) + return -1; + + if (get_insn(regs, epc, &insn)) + return -1; regs->epc = 0; @@ -336,6 +536,14 @@ int handle_misaligned_store(struct pt_regs *regs) } else if ((insn & INSN_MASK_SD) == INSN_MATCH_SD) { len = 8; #endif + } else if ((insn & INSN_MASK_FSD) == INSN_MATCH_FSD) { + fp = 1; + len = 8; + val.data_u64 = GET_F64_RS2(insn, regs); + } else if ((insn & INSN_MASK_FSW) == INSN_MATCH_FSW) { + fp = 1; + len = 4; + val.data_ulong = GET_F32_RS2(insn, regs); } else if ((insn & INSN_MASK_SH) == INSN_MATCH_SH) { len = 2; #if defined(CONFIG_64BIT) @@ -354,15 +562,88 @@ int handle_misaligned_store(struct pt_regs *regs) ((insn >> SH_RD) & 0x1f)) { len = 4; val.data_ulong = GET_RS2C(insn, regs); + } else if ((insn & INSN_MASK_C_FSD) == INSN_MATCH_C_FSD) { + fp = 1; + len = 8; + val.data_u64 = GET_F64_RS2S(insn, regs); + } else if ((insn & INSN_MASK_C_FSDSP) == INSN_MATCH_C_FSDSP) { + fp = 1; + len = 8; + val.data_u64 = GET_F64_RS2C(insn, regs); +#if !defined(CONFIG_64BIT) + } else if ((insn & INSN_MASK_C_FSW) == INSN_MATCH_C_FSW) { + fp = 1; + len = 4; + val.data_ulong = GET_F32_RS2S(insn, regs); + } else if ((insn & INSN_MASK_C_FSWSP) == INSN_MATCH_C_FSWSP) { + fp = 1; + len = 4; + val.data_ulong = GET_F32_RS2C(insn, regs); +#endif } else { regs->epc = epc; return -1; } - for (i = 0; i < len; i++) - store_u8((void *)(addr + i), val.data_bytes[i]); + if (!IS_ENABLED(CONFIG_FPU) && fp) + return -EOPNOTSUPP; + + for (i = 0; i < len; i++) { + if (store_u8(regs, (void *)(addr + i), val.data_bytes[i])) + return -1; + } regs->epc = epc + INSN_LEN(insn); return 0; } + +bool check_unaligned_access_emulated(int cpu) +{ + long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); + unsigned long tmp_var, tmp_val; + bool misaligned_emu_detected; + + *mas_ptr = RISCV_HWPROBE_MISALIGNED_UNKNOWN; + + __asm__ __volatile__ ( + " "REG_L" %[tmp], 1(%[ptr])\n" + : [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory"); + + misaligned_emu_detected = (*mas_ptr == RISCV_HWPROBE_MISALIGNED_EMULATED); + /* + * If unaligned_ctl is already set, this means that we detected that all + * CPUS uses emulated misaligned access at boot time. If that changed + * when hotplugging the new cpu, this is something we don't handle. + */ + if (unlikely(unaligned_ctl && !misaligned_emu_detected)) { + pr_crit("CPU misaligned accesses non homogeneous (expected all emulated)\n"); + while (true) + cpu_relax(); + } + + return misaligned_emu_detected; +} + +void __init unaligned_emulation_finish(void) +{ + int cpu; + + /* + * We can only support PR_UNALIGN controls if all CPUs have misaligned + * accesses emulated since tasks requesting such control can run on any + * CPU. + */ + for_each_present_cpu(cpu) { + if (per_cpu(misaligned_access_speed, cpu) != + RISCV_HWPROBE_MISALIGNED_EMULATED) { + return; + } + } + unaligned_ctl = true; +} + +bool unaligned_ctl_available(void) +{ + return unaligned_ctl; +} |