Straightforward, except for save_altstack_ex() stuck in those. Replace that thing with an analogue that would use unsafe_put_user() instead of put_user_ex() (called compat_save_altstack()) and be done with that.
Unified · Split
| @@ -365,38 +365,37 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, · 364 unmodified lines | |||
| 365 | 365 | ||
| 366 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); | 366 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
| 367 | 367 | ||
| 368 | if (!access_ok(frame, sizeof(*frame))) | 368 | if (!user_access_begin(frame, sizeof(*frame))) |
| 369 | return -EFAULT; | 369 | return -EFAULT; |
| 370 | 370 | ||
| 371 | put_user_try { | 371 | unsafe_put_user(sig, &frame->sig, Efault); |
| 372 | put_user_ex(sig, &frame->sig); | 372 | unsafe_put_user(&frame->info, &frame->pinfo, Efault); |
| 373 | put_user_ex(&frame->info, &frame->pinfo); | 373 | unsafe_put_user(&frame->uc, &frame->puc, Efault); |
| 374 | put_user_ex(&frame->uc, &frame->puc); | ||
| 375 | 374 | ||
| 376 | /* Create the ucontext. */ | 375 | /* Create the ucontext. */ |
| 377 | if (static_cpu_has(X86_FEATURE_XSAVE)) | 376 | if (static_cpu_has(X86_FEATURE_XSAVE)) |
| 378 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | 377 | unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault); |
| 379 | else | 378 | else |
| 380 | put_user_ex(0, &frame->uc.uc_flags); | 379 | unsafe_put_user(0, &frame->uc.uc_flags, Efault); |
| 381 | put_user_ex(0, &frame->uc.uc_link); | 380 | unsafe_put_user(0, &frame->uc.uc_link, Efault); |
| 382 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); | 381 | unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault); |
| 383 | 382 | ||
| 384 | /* Set up to return from userspace. */ | 383 | /* Set up to return from userspace. */ |
| 385 | restorer = current->mm->context.vdso + | 384 | restorer = current->mm->context.vdso + |
| 386 | vdso_image_32.sym___kernel_rt_sigreturn; | 385 | vdso_image_32.sym___kernel_rt_sigreturn; |
| 387 | if (ksig->ka.sa.sa_flags & SA_RESTORER) | 386 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 388 | restorer = ksig->ka.sa.sa_restorer; | 387 | restorer = ksig->ka.sa.sa_restorer; |
| 389 | put_user_ex(restorer, &frame->pretcode); | 388 | unsafe_put_user(restorer, &frame->pretcode, Efault); |
| 390 | 389 | ||
| 391 | /* | 390 | /* |
| 392 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 | 391 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 |
| 393 | * | 392 | * |
| 394 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | 393 | * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| 395 | * reasons and because gdb uses it as a signature to notice | 394 | * reasons and because gdb uses it as a signature to notice |
| 396 | * signal handler stack frames. | 395 | * signal handler stack frames. |
| 397 | */ | 396 | */ |
| 398 | put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); | 397 | unsafe_put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode, Efault); |
| 399 | } put_user_catch(err); | 398 | user_access_end(); |
| 400 | 399 | ||
| 401 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); | 400 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 402 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, | 401 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
| @@ -419,6 +418,9 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, · 16 unmodified lines | |||
| 419 | regs->cs = __USER_CS; | 418 | regs->cs = __USER_CS; |
| 420 | 419 | ||
| 421 | return 0; | 420 | return 0; |
| 421 | Efault: | ||
| 422 | user_access_end(); | ||
| 423 | return -EFAULT; | ||
| 422 | } | 424 | } |
| 423 | #else /* !CONFIG_X86_32 */ | 425 | #else /* !CONFIG_X86_32 */ |
| 424 | static unsigned long frame_uc_flags(struct pt_regs *regs) | 426 | static unsigned long frame_uc_flags(struct pt_regs *regs) |
| @@ -444,6 +446,10 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, · 19 unmodified lines | |||
| 444 | unsigned long uc_flags; | 446 | unsigned long uc_flags; |
| 445 | int err = 0; | 447 | int err = 0; |
| 446 | 448 | ||
| 449 | /* x86-64 should always use SA_RESTORER. */ | ||
| 450 | if (!(ksig->ka.sa.sa_flags & SA_RESTORER)) | ||
| 451 | return -EFAULT; | ||
| 452 | |||
| 447 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); | 453 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
| 448 | 454 | ||
| 449 | if (!access_ok(frame, sizeof(*frame))) | 455 | if (!access_ok(frame, sizeof(*frame))) |
| @@ -455,23 +461,18 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, · 5 unmodified lines | |||
| 455 | } | 461 | } |
| 456 | 462 | ||
| 457 | uc_flags = frame_uc_flags(regs); | 463 | uc_flags = frame_uc_flags(regs); |
| 464 | if (!user_access_begin(frame, sizeof(*frame))) | ||
| 465 | return -EFAULT; | ||
| 458 | 466 | ||
| 459 | put_user_try { | 467 | /* Create the ucontext. */ |
| 460 | /* Create the ucontext. */ | 468 | unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault); |
| 461 | put_user_ex(uc_flags, &frame->uc.uc_flags); | 469 | unsafe_put_user(0, &frame->uc.uc_link, Efault); |
| 462 | put_user_ex(0, &frame->uc.uc_link); | 470 | unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault); |
| 463 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); | 471 | |
| 464 | 472 | /* Set up to return from userspace. If provided, use a stub | |
| 465 | /* Set up to return from userspace. If provided, use a stub | 473 | already in userspace. */ |
| 466 | already in userspace. */ | 474 | unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault); |
| 467 | /* x86-64 should always use SA_RESTORER. */ | 475 | user_access_end(); |
| 468 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { | ||
| 469 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | ||
| 470 | } else { | ||
| 471 | /* could use a vstub here */ | ||
| 472 | err |= -EFAULT; | ||
| 473 | } | ||
| 474 | } put_user_catch(err); | ||
| 475 | 476 | ||
| 476 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); | 477 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
| 477 | err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); | 478 | err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); |
| @@ -515,6 +516,10 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, · 37 unmodified lines | |||
| 515 | force_valid_ss(regs); | 516 | force_valid_ss(regs); |
| 516 | 517 | ||
| 517 | return 0; | 518 | return 0; |
| 519 | |||
| 520 | Efault: | ||
| 521 | user_access_end(); | ||
| 522 | return -EFAULT; | ||
| 518 | } | 523 | } |
| 519 | #endif /* CONFIG_X86_32 */ | 524 | #endif /* CONFIG_X86_32 */ |
| 520 | 525 | ||
| @@ -444,12 +444,12 @@ void signals_init(void); · 443 unmodified lines | |||
| 444 | int restore_altstack(const stack_t __user *); | 444 | int restore_altstack(const stack_t __user *); |
| 445 | int __save_altstack(stack_t __user *, unsigned long); | 445 | int __save_altstack(stack_t __user *, unsigned long); |
| 446 | 446 | ||
| 447 | #define save_altstack_ex(uss, sp) do { \ | 447 | #define unsafe_save_altstack(uss, sp, label) do { \ |
| 448 | stack_t __user *__uss = uss; \ | 448 | stack_t __user *__uss = uss; \ |
| 449 | struct task_struct *t = current; \ | 449 | struct task_struct *t = current; \ |
| 450 | put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ | 450 | unsafe_put_user((void __user *)t->sas_ss_sp, &__uss->ss_sp, label); \ |
| 451 | put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \ | 451 | unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \ |
| 452 | put_user_ex(t->sas_ss_size, &__uss->ss_size); \ | 452 | unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \ |
| 453 | if (t->sas_ss_flags & SS_AUTODISARM) \ | 453 | if (t->sas_ss_flags & SS_AUTODISARM) \ |
| 454 | sas_ss_reset(t); \ | 454 | sas_ss_reset(t); \ |
| 455 | } while (0); | 455 | } while (0); |