Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Vineet Gupta | 4adeefe | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 4 | * |
Vineet Gupta | 4adeefe | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 5 | * Amit Bhor, Kanika Nema: Codito Technologies 2004 |
| 6 | */ |
| 7 | |
| 8 | #include <linux/errno.h> |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/sched.h> |
Ingo Molnar | 2993002 | 2017-02-08 18:51:36 +0100 | [diff] [blame] | 11 | #include <linux/sched/task.h> |
Ingo Molnar | 68db0cf | 2017-02-08 18:51:37 +0100 | [diff] [blame] | 12 | #include <linux/sched/task_stack.h> |
Ingo Molnar | 2993002 | 2017-02-08 18:51:36 +0100 | [diff] [blame] | 13 | |
Vineet Gupta | 4adeefe | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 14 | #include <linux/mm.h> |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/unistd.h> |
| 17 | #include <linux/ptrace.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/syscalls.h> |
| 20 | #include <linux/elf.h> |
| 21 | #include <linux/tick.h> |
| 22 | |
| 23 | SYSCALL_DEFINE1(arc_settls, void *, user_tls_data_ptr) |
| 24 | { |
| 25 | task_thread_info(current)->thr_ptr = (unsigned int)user_tls_data_ptr; |
| 26 | return 0; |
| 27 | } |
| 28 | |
| 29 | /* |
| 30 | * We return the user space TLS data ptr as sys-call return code |
| 31 | * Ideally it should be copy to user. |
| 32 | * However we can cheat by the fact that some sys-calls do return |
| 33 | * absurdly high values |
| 34 | * Since the tls dat aptr is not going to be in range of 0xFFFF_xxxx |
| 35 | * it won't be considered a sys-call error |
| 36 | * and it will be loads better than copy-to-user, which is a definite |
| 37 | * D-TLB Miss |
| 38 | */ |
| 39 | SYSCALL_DEFINE0(arc_gettls) |
| 40 | { |
| 41 | return task_thread_info(current)->thr_ptr; |
| 42 | } |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 43 | |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 44 | SYSCALL_DEFINE3(arc_usr_cmpxchg, int *, uaddr, int, expected, int, new) |
| 45 | { |
Vineet Gupta | e6e335b | 2016-11-07 10:36:46 -0800 | [diff] [blame] | 46 | struct pt_regs *regs = current_pt_regs(); |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 47 | u32 uval; |
| 48 | int ret; |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 49 | |
| 50 | /* |
| 51 | * This is only for old cores lacking LLOCK/SCOND, which by defintion |
| 52 | * can't possibly be SMP. Thus doesn't need to be SMP safe. |
| 53 | * And this also helps reduce the overhead for serializing in |
| 54 | * the UP case |
| 55 | */ |
| 56 | WARN_ON_ONCE(IS_ENABLED(CONFIG_SMP)); |
| 57 | |
Vineet Gupta | e6e335b | 2016-11-07 10:36:46 -0800 | [diff] [blame] | 58 | /* Z indicates to userspace if operation succeded */ |
| 59 | regs->status32 &= ~STATUS_Z_MASK; |
| 60 | |
Linus Torvalds | 96d4f26 | 2019-01-03 18:57:57 -0800 | [diff] [blame] | 61 | ret = access_ok(uaddr, sizeof(*uaddr)); |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 62 | if (!ret) |
| 63 | goto fail; |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 64 | |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 65 | again: |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 66 | preempt_disable(); |
| 67 | |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 68 | ret = __get_user(uval, uaddr); |
| 69 | if (ret) |
| 70 | goto fault; |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 71 | |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 72 | if (uval != expected) |
| 73 | goto out; |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 74 | |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 75 | ret = __put_user(new, uaddr); |
| 76 | if (ret) |
| 77 | goto fault; |
| 78 | |
| 79 | regs->status32 |= STATUS_Z_MASK; |
| 80 | |
| 81 | out: |
| 82 | preempt_enable(); |
| 83 | return uval; |
| 84 | |
| 85 | fault: |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 86 | preempt_enable(); |
| 87 | |
Peter Zijlstra | e870878 | 2018-06-19 17:22:05 +0300 | [diff] [blame] | 88 | if (unlikely(ret != -EFAULT)) |
| 89 | goto fail; |
| 90 | |
| 91 | down_read(¤t->mm->mmap_sem); |
| 92 | ret = fixup_user_fault(current, current->mm, (unsigned long) uaddr, |
| 93 | FAULT_FLAG_WRITE, NULL); |
| 94 | up_read(¤t->mm->mmap_sem); |
| 95 | |
| 96 | if (likely(!ret)) |
| 97 | goto again; |
| 98 | |
| 99 | fail: |
| 100 | force_sig(SIGSEGV, current); |
| 101 | return ret; |
Vineet Gupta | 91e040a | 2016-10-20 07:39:45 -0700 | [diff] [blame] | 102 | } |
| 103 | |
Vineet Gupta | 64f42ce | 2017-06-02 11:49:10 -0700 | [diff] [blame] | 104 | #ifdef CONFIG_ISA_ARCV2 |
| 105 | |
Thomas Gleixner | fa35e42 | 2013-03-21 22:49:36 +0100 | [diff] [blame] | 106 | void arch_cpu_idle(void) |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 107 | { |
Vineet Gupta | 64f42ce | 2017-06-02 11:49:10 -0700 | [diff] [blame] | 108 | /* Re-enable interrupts <= default irq priority before commiting SLEEP */ |
| 109 | const unsigned int arg = 0x10 | ARCV2_IRQ_DEF_PRIO; |
| 110 | |
Vineet Gupta | 512b5b8 | 2015-11-16 13:52:07 +0530 | [diff] [blame] | 111 | __asm__ __volatile__( |
| 112 | "sleep %0 \n" |
| 113 | : |
Vineet Gupta | 64f42ce | 2017-06-02 11:49:10 -0700 | [diff] [blame] | 114 | :"I"(arg)); /* can't be "r" has to be embedded const */ |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 115 | } |
| 116 | |
Noam Camus | 644fa02 | 2017-05-28 09:52:06 +0300 | [diff] [blame] | 117 | #elif defined(CONFIG_EZNPS_MTM_EXT) /* ARC700 variant in NPS */ |
| 118 | |
| 119 | void arch_cpu_idle(void) |
| 120 | { |
| 121 | /* only the calling HW thread needs to sleep */ |
| 122 | __asm__ __volatile__( |
| 123 | ".word %0 \n" |
| 124 | : |
| 125 | :"i"(CTOP_INST_HWSCHD_WFT_IE12)); |
| 126 | } |
| 127 | |
| 128 | #else /* ARC700 */ |
Vineet Gupta | 64f42ce | 2017-06-02 11:49:10 -0700 | [diff] [blame] | 129 | |
| 130 | void arch_cpu_idle(void) |
| 131 | { |
| 132 | /* sleep, but enable both set E1/E2 (levels of interrutps) before committing */ |
| 133 | __asm__ __volatile__("sleep 0x3 \n"); |
| 134 | } |
| 135 | |
| 136 | #endif |
| 137 | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 138 | asmlinkage void ret_from_fork(void); |
| 139 | |
Alex Dowad | 18e1d1b | 2015-03-13 20:04:18 +0200 | [diff] [blame] | 140 | /* |
| 141 | * Copy architecture-specific thread state |
| 142 | * |
| 143 | * Layout of Child kernel mode stack as setup at the end of this function is |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 144 | * |
| 145 | * | ... | |
| 146 | * | ... | |
| 147 | * | unused | |
| 148 | * | | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 149 | * ------------------ |
Vineet Gupta | 16f9afe | 2013-05-27 21:43:41 +0530 | [diff] [blame] | 150 | * | r25 | <==== top of Stack (thread.ksp) |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 151 | * ~ ~ |
Vineet Gupta | 0907495 | 2015-08-19 17:23:58 +0530 | [diff] [blame] | 152 | * | --to-- | (CALLEE Regs of kernel mode) |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 153 | * | r13 | |
| 154 | * ------------------ |
| 155 | * | fp | |
| 156 | * | blink | @ret_from_fork |
| 157 | * ------------------ |
| 158 | * | | |
| 159 | * ~ ~ |
| 160 | * ~ ~ |
| 161 | * | | |
| 162 | * ------------------ |
| 163 | * | r12 | |
| 164 | * ~ ~ |
| 165 | * | --to-- | (scratch Regs of user mode) |
| 166 | * | r0 | |
Vineet Gupta | 3ebedbb | 2013-05-28 13:24:43 +0530 | [diff] [blame] | 167 | * ------------------ |
| 168 | * | SP | |
| 169 | * | orig_r0 | |
Vineet Gupta | 502a0c7 | 2013-06-11 18:56:54 +0530 | [diff] [blame] | 170 | * | event/ECR | |
Vineet Gupta | 359105b | 2013-05-28 13:50:41 +0530 | [diff] [blame] | 171 | * | user_r25 | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 172 | * ------------------ <===== END of PAGE |
| 173 | */ |
| 174 | int copy_thread(unsigned long clone_flags, |
Alex Dowad | 18e1d1b | 2015-03-13 20:04:18 +0200 | [diff] [blame] | 175 | unsigned long usp, unsigned long kthread_arg, |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 176 | struct task_struct *p) |
| 177 | { |
| 178 | struct pt_regs *c_regs; /* child's pt_regs */ |
| 179 | unsigned long *childksp; /* to unwind out of __switch_to() */ |
| 180 | struct callee_regs *c_callee; /* child's callee regs */ |
| 181 | struct callee_regs *parent_callee; /* paren't callee */ |
| 182 | struct pt_regs *regs = current_pt_regs(); |
| 183 | |
| 184 | /* Mark the specific anchors to begin with (see pic above) */ |
| 185 | c_regs = task_pt_regs(p); |
| 186 | childksp = (unsigned long *)c_regs - 2; /* 2 words for FP/BLINK */ |
| 187 | c_callee = ((struct callee_regs *)childksp) - 1; |
| 188 | |
| 189 | /* |
| 190 | * __switch_to() uses thread.ksp to start unwinding stack |
| 191 | * For kernel threads we don't need to create callee regs, the |
| 192 | * stack layout nevertheless needs to remain the same. |
| 193 | * Also, since __switch_to anyways unwinds callee regs, we use |
| 194 | * this to populate kernel thread entry-pt/args into callee regs, |
| 195 | * so that ret_from_kernel_thread() becomes simpler. |
| 196 | */ |
| 197 | p->thread.ksp = (unsigned long)c_callee; /* THREAD_KSP */ |
| 198 | |
| 199 | /* __switch_to expects FP(0), BLINK(return addr) at top */ |
| 200 | childksp[0] = 0; /* fp */ |
| 201 | childksp[1] = (unsigned long)ret_from_fork; /* blink */ |
| 202 | |
| 203 | if (unlikely(p->flags & PF_KTHREAD)) { |
| 204 | memset(c_regs, 0, sizeof(struct pt_regs)); |
| 205 | |
Alex Dowad | 18e1d1b | 2015-03-13 20:04:18 +0200 | [diff] [blame] | 206 | c_callee->r13 = kthread_arg; |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 207 | c_callee->r14 = usp; /* function */ |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | /*--------- User Task Only --------------*/ |
| 213 | |
| 214 | /* __switch_to expects FP(0), BLINK(return addr) at top of stack */ |
| 215 | childksp[0] = 0; /* for POP fp */ |
| 216 | childksp[1] = (unsigned long)ret_from_fork; /* for POP blink */ |
| 217 | |
| 218 | /* Copy parents pt regs on child's kernel mode stack */ |
| 219 | *c_regs = *regs; |
| 220 | |
| 221 | if (usp) |
| 222 | c_regs->sp = usp; |
| 223 | |
| 224 | c_regs->r0 = 0; /* fork returns 0 in child */ |
| 225 | |
| 226 | parent_callee = ((struct callee_regs *)regs) - 1; |
| 227 | *c_callee = *parent_callee; |
| 228 | |
| 229 | if (unlikely(clone_flags & CLONE_SETTLS)) { |
| 230 | /* |
| 231 | * set task's userland tls data ptr from 4th arg |
| 232 | * clone C-lib call is difft from clone sys-call |
| 233 | */ |
| 234 | task_thread_info(p)->thr_ptr = regs->r3; |
| 235 | } else { |
| 236 | /* Normal fork case: set parent's TLS ptr in child */ |
| 237 | task_thread_info(p)->thr_ptr = |
| 238 | task_thread_info(current)->thr_ptr; |
| 239 | } |
| 240 | |
Vineet Gupta | c58a584 | 2018-10-05 12:48:48 -0700 | [diff] [blame] | 241 | |
| 242 | /* |
| 243 | * setup usermode thread pointer #1: |
| 244 | * when child is picked by scheduler, __switch_to() uses @c_callee to |
| 245 | * populate usermode callee regs: this works (despite being in a kernel |
| 246 | * function) since special return path for child @ret_from_fork() |
| 247 | * ensures those regs are not clobbered all the way to RTIE to usermode |
| 248 | */ |
| 249 | c_callee->r25 = task_thread_info(p)->thr_ptr; |
| 250 | |
| 251 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 252 | /* |
| 253 | * setup usermode thread pointer #2: |
| 254 | * however for this special use of r25 in kernel, __switch_to() sets |
| 255 | * r25 for kernel needs and only in the final return path is usermode |
| 256 | * r25 setup, from pt_regs->user_r25. So set that up as well |
| 257 | */ |
| 258 | c_regs->user_r25 = c_callee->r25; |
| 259 | #endif |
| 260 | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | /* |
Vineet Gupta | 2ab402d | 2014-04-18 12:19:59 +0530 | [diff] [blame] | 265 | * Do necessary setup to start up a new user task |
| 266 | */ |
| 267 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp) |
| 268 | { |
Vineet Gupta | 2ab402d | 2014-04-18 12:19:59 +0530 | [diff] [blame] | 269 | regs->sp = usp; |
| 270 | regs->ret = pc; |
| 271 | |
| 272 | /* |
| 273 | * [U]ser Mode bit set |
| 274 | * [L] ZOL loop inhibited to begin with - cleared by a LP insn |
| 275 | * Interrupts enabled |
| 276 | */ |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 277 | regs->status32 = STATUS_U_MASK | STATUS_L_MASK | ISA_INIT_STATUS_BITS; |
Vineet Gupta | 2ab402d | 2014-04-18 12:19:59 +0530 | [diff] [blame] | 278 | |
Liav Rehana | 28923f6 | 2017-06-15 11:44:00 +0300 | [diff] [blame] | 279 | #ifdef CONFIG_EZNPS_MTM_EXT |
| 280 | regs->eflags = 0; |
| 281 | #endif |
| 282 | |
Vineet Gupta | 2ab402d | 2014-04-18 12:19:59 +0530 | [diff] [blame] | 283 | /* bogus seed values for debugging */ |
| 284 | regs->lp_start = 0x10; |
| 285 | regs->lp_end = 0x80; |
| 286 | } |
| 287 | |
| 288 | /* |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 289 | * Some archs flush debug and FPU info here |
| 290 | */ |
| 291 | void flush_thread(void) |
| 292 | { |
| 293 | } |
| 294 | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 295 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) |
| 296 | { |
| 297 | return 0; |
| 298 | } |
| 299 | |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 300 | int elf_check_arch(const struct elf32_hdr *x) |
| 301 | { |
| 302 | unsigned int eflags; |
| 303 | |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 304 | if (x->e_machine != EM_ARC_INUSE) { |
| 305 | pr_err("ELF not built for %s ISA\n", |
| 306 | is_isa_arcompact() ? "ARCompact":"ARCv2"); |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 307 | return 0; |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 308 | } |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 309 | |
| 310 | eflags = x->e_flags; |
Vineet Gupta | 840c054 | 2016-08-10 14:10:57 -0700 | [diff] [blame] | 311 | if ((eflags & EF_ARC_OSABI_MSK) != EF_ARC_OSABI_CURRENT) { |
Vineet Gupta | bf90e1e | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 312 | pr_err("ABI mismatch - you need newer toolchain\n"); |
| 313 | force_sigsegv(SIGSEGV, current); |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | return 1; |
| 318 | } |
| 319 | EXPORT_SYMBOL(elf_check_arch); |