From cb9d1cc0d8fad13070871506a790cadd2043acb2 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Tue, 24 May 2016 03:04:50 +0300 Subject: arm64: ilp32: introduce ilp32-specific handlers for sigframe and ucontext ILP32 uses AARCH32 compat structures and syscall handlers for signals. But ILP32 struct rt_sigframe and ucontext differs from both LP64 and AARCH32. So some specific mechanism is needed to take care of it. Signed-off-by: Yury Norov --- arch/arm64/include/asm/signal_ilp32.h | 35 +++ arch/arm64/kernel/Makefile | 3 +- arch/arm64/kernel/entry_ilp32.S | 22 ++ arch/arm64/kernel/signal.c | 3 + arch/arm64/kernel/signal_ilp32.c | 408 ++++++++++++++++++++++++++++++++++ 5 files changed, 470 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/signal_ilp32.h create mode 100644 arch/arm64/kernel/entry_ilp32.S create mode 100644 arch/arm64/kernel/signal_ilp32.c diff --git a/arch/arm64/include/asm/signal_ilp32.h b/arch/arm64/include/asm/signal_ilp32.h new file mode 100644 index 000000000000..7f9a2a241bbf --- /dev/null +++ b/arch/arm64/include/asm/signal_ilp32.h @@ -0,0 +1,35 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#ifndef __ASM_SIGNAL_ILP32_H +#define __ASM_SIGNAL_ILP32_H + +#ifdef CONFIG_ARM64_ILP32 + +#include + +int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, + struct pt_regs *regs); + +#else + +static inline int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, + struct pt_regs *regs) +{ + return -ENOSYS; +} + +#endif /* CONFIG_ARM64_ILP32 */ + +#endif /* __ASM_SIGNAL_ILP32_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 91ebde67be6a..2ccb4e743a71 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -28,7 +28,8 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE arm64-obj-$(CONFIG_AARCH32_EL0) += sys32.o kuser32.o signal32.o \ sys_compat.o entry32.o binfmt_elf32.o -arm64-obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o sys_ilp32.o +arm64-obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o sys_ilp32.o \ + signal_ilp32.o entry_ilp32.o arm64-obj-$(CONFIG_COMPAT) += entry32_common.o signal32_common.o arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o diff --git a/arch/arm64/kernel/entry_ilp32.S b/arch/arm64/kernel/entry_ilp32.S new file mode 100644 index 000000000000..a8bb94b3901b --- /dev/null +++ b/arch/arm64/kernel/entry_ilp32.S @@ -0,0 +1,22 @@ +/* + * ILP32 system call wrappers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include + +ENTRY(ilp32_sys_rt_sigreturn_wrapper) + mov x0, sp + b ilp32_sys_rt_sigreturn +ENDPROC(ilp32_sys_rt_sigreturn_wrapper) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 587c0a532fa7..8531e4b49405 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -42,6 +42,7 @@ #include #include #include +#include /* * Do a signal return; undo the signal stack. These are aligned to 128-bit. @@ -775,6 +776,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) ret = a32_setup_rt_frame(usig, ksig, oldset, regs); else ret = a32_setup_frame(usig, ksig, oldset, regs); + } else if (is_ilp32_compat_task()) { + ret = ilp32_setup_rt_frame(usig, ksig, oldset, regs); } else { ret = setup_rt_frame(usig, ksig, oldset, regs); } diff --git a/arch/arm64/kernel/signal_ilp32.c b/arch/arm64/kernel/signal_ilp32.c new file mode 100644 index 000000000000..a1cb0580a6d4 --- /dev/null +++ b/arch/arm64/kernel/signal_ilp32.c @@ -0,0 +1,408 @@ +/* + * Based on arch/arm/kernel/signal.c + * + * Copyright (C) 1995-2009 Russell King + * Copyright (C) 2012 ARM Ltd. + * Copyright (C) 2017 Cavium Networks. + * Yury Norov + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include + +#include +#include +#include +#include + +#include +#include +#include + +#define BASE_SIGFRAME_SIZE round_up(sizeof(struct ilp32_rt_sigframe), 16) + +struct ilp32_ucontext { + u32 uc_flags; + u32 uc_link; + compat_stack_t uc_stack; + compat_sigset_t uc_sigmask; + /* glibc uses a 1024-bit sigset_t */ + __u8 __unused[1024 / 8 - sizeof(compat_sigset_t)]; + /* last for future expansion */ + struct sigcontext uc_mcontext; +}; + +struct ilp32_rt_sigframe { + struct compat_siginfo info; + struct ilp32_ucontext uc; +}; + +struct ilp32_rt_sigframe_user_layout { + struct ilp32_rt_sigframe __user *sigframe; + struct frame_record __user *next_frame; + + unsigned int size; /* size of allocated sigframe data */ + unsigned int limit; /* largest allowed size */ + + unsigned int fpsimd_offset; + unsigned int esr_offset; + unsigned int sve_offset; + unsigned int extra_offset; + unsigned int end_offset; +}; + +static size_t ilp32_sigframe_size(struct ilp32_rt_sigframe_user_layout const *user) +{ + return round_up(max(user->size, (unsigned int)sizeof(struct ilp32_rt_sigframe)), 16); +} + +static void __user *apply_user_offset( + struct ilp32_rt_sigframe_user_layout const *user, unsigned long offset) +{ + char __user *base = (char __user *)user->sigframe; + + return base + offset; +} + +static void ilp32_init_user_layout(struct ilp32_rt_sigframe_user_layout *user) +{ + const size_t reserved_size = + sizeof(user->sigframe->uc.uc_mcontext.__reserved); + + memset(user, 0, sizeof(*user)); + user->size = offsetof(struct ilp32_rt_sigframe, uc.uc_mcontext.__reserved); + + user->limit = user->size + reserved_size; + + user->limit -= TERMINATOR_SIZE; + user->limit -= EXTRA_CONTEXT_SIZE; + /* Reserve space for extension and terminator ^ */ +} + +static int ilp32_restore_sigframe(struct pt_regs *regs, + struct ilp32_rt_sigframe __user *sf) +{ + sigset_t set; + int i, err; + struct user_ctxs user; + + err = get_sigset_t(&set, &sf->uc.uc_sigmask); + if (err == 0) + set_current_blocked(&set); + + for (i = 0; i < 31; i++) + __get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], + err); + __get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); + __get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); + __get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); + + /* + * Avoid sys_rt_sigreturn() restarting. + */ + forget_syscall(regs); + + err |= !valid_user_regs(®s->user_regs, current); + if (err == 0) + err = parse_user_sigcontext(&user, sf); + + if (err == 0) { + if (!user.fpsimd) + return -EINVAL; + + if (user.sve) { + if (!system_supports_sve()) + return -EINVAL; + + err = restore_sve_fpsimd_context(&user); + } else { + err = restore_fpsimd_context(user.fpsimd); + } + } + + return err; +} +asmlinkage long ilp32_sys_rt_sigreturn(struct pt_regs *regs) +{ + struct ilp32_rt_sigframe __user *frame; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + /* + * Since we stacked the signal on a 128-bit boundary, then 'sp' should + * be word aligned here. + */ + if (regs->sp & 15) + goto badframe; + + frame = (struct ilp32_rt_sigframe __user *)regs->sp; + + if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) + goto badframe; + + if (ilp32_restore_sigframe(regs, frame)) + goto badframe; + + if (compat_restore_altstack(&frame->uc.uc_stack)) + goto badframe; + + return regs->regs[0]; + +badframe: + if (show_unhandled_signals) + pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n", + current->comm, task_pid_nr(current), __func__, + regs->pc, regs->sp); + force_sig(SIGSEGV, current); + return 0; +} + +static int __ilp32_sigframe_alloc(struct ilp32_rt_sigframe_user_layout *user, + unsigned int *offset, size_t size, bool extend) +{ + size_t padded_size = round_up(size, 16); + + if (padded_size > user->limit - user->size && + !user->extra_offset && + extend) { + int ret; + + user->limit += EXTRA_CONTEXT_SIZE; + ret = __ilp32_sigframe_alloc(user, &user->extra_offset, + sizeof(struct extra_context), false); + if (ret) { + user->limit -= EXTRA_CONTEXT_SIZE; + return ret; + } + + /* Reserve space for the __reserved[] terminator */ + user->size += TERMINATOR_SIZE; + + /* + * Allow expansion up to SIGFRAME_MAXSZ, ensuring space for + * the terminator: + */ + user->limit = SIGFRAME_MAXSZ - TERMINATOR_SIZE; + } + + /* Still not enough space? Bad luck! */ + if (padded_size > user->limit - user->size) + return -ENOMEM; + + *offset = user->size; + user->size += padded_size; + + return 0; +} + +/* + * Allocate space for an optional record of bytes in the user + * signal frame. The offset from the signal frame base address to the + * allocated block is assigned to *offset. + */ +static int ilp32_sigframe_alloc(struct ilp32_rt_sigframe_user_layout *user, + unsigned int *offset, size_t size) +{ + return __ilp32_sigframe_alloc(user, offset, size, true); +} + +/* Allocate the null terminator record and prevent further allocations */ +static int ilp32_sigframe_alloc_end(struct ilp32_rt_sigframe_user_layout *user) +{ + int ret; + + /* Un-reserve the space reserved for the terminator: */ + user->limit += TERMINATOR_SIZE; + + ret = ilp32_sigframe_alloc(user, &user->end_offset, + sizeof(struct _aarch64_ctx)); + if (ret) + return ret; + + /* Prevent further allocation: */ + user->limit = user->size; + return 0; +} + +/* Determine the layout of optional records in the signal frame */ +static int ilp32_setup_sigframe_layout(struct ilp32_rt_sigframe_user_layout *user) +{ + int err; + + err = ilp32_sigframe_alloc(user, &user->fpsimd_offset, + sizeof(struct fpsimd_context)); + if (err) + return err; + + /* fault information, if valid */ + if (current->thread.fault_code) { + err = ilp32_sigframe_alloc(user, &user->esr_offset, + sizeof(struct esr_context)); + if (err) + return err; + } + + if (system_supports_sve()) { + unsigned int vq = 0; + + if (test_thread_flag(TIF_SVE)) + vq = sve_vq_from_vl(current->thread.sve_vl); + + err = ilp32_sigframe_alloc(user, &user->sve_offset, + SVE_SIG_CONTEXT_SIZE(vq)); + if (err) + return err; + } + + return ilp32_sigframe_alloc_end(user); +} + +static int ilp32_setup_sigframe(struct ilp32_rt_sigframe_user_layout *user, + struct pt_regs *regs, sigset_t *set) +{ + int i, err = 0; + struct ilp32_rt_sigframe __user *sf = user->sigframe; + + /* set up the stack frame for unwinding */ + __put_user_error(regs->regs[29], &user->next_frame->fp, err); + __put_user_error(regs->regs[30], &user->next_frame->lr, err); + + for (i = 0; i < 31; i++) + __put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], + err); + __put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); + __put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); + __put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); + + __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err); + + err |= put_sigset_t(&sf->uc.uc_sigmask, set); + + if (err == 0) { + struct fpsimd_context __user *fpsimd_ctx = + apply_user_offset(user, user->fpsimd_offset); + err |= preserve_fpsimd_context(fpsimd_ctx); + } + + /* fault information, if valid */ + if (err == 0 && user->esr_offset) { + struct esr_context __user *esr_ctx = + apply_user_offset(user, user->esr_offset); + + __put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err); + __put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err); + __put_user_error(current->thread.fault_code, &esr_ctx->esr, err); + } + + /* Scalable Vector Extension state, if present */ + if (system_supports_sve() && err == 0 && user->sve_offset) { + struct sve_context __user *sve_ctx = + apply_user_offset(user, user->sve_offset); + err |= preserve_sve_context(sve_ctx); + } + + if (err == 0 && user->extra_offset) + setup_extra_context((char *) user->sigframe, user->size, + (char *) apply_user_offset(user, user->extra_offset)); + + /* set the "end" magic */ + if (err == 0) { + struct _aarch64_ctx __user *end = + apply_user_offset(user, user->end_offset); + + __put_user_error(0, &end->magic, err); + __put_user_error(0, &end->size, err); + } + + return err; +} + +static int ilp32_get_sigframe(struct ilp32_rt_sigframe_user_layout *user, + struct ksignal *ksig, struct pt_regs *regs) +{ + unsigned long sp, sp_top; + int err; + + ilp32_init_user_layout(user); + err = ilp32_setup_sigframe_layout(user); + if (err) + return err; + + sp = sp_top = sigsp(regs->sp, ksig); + + sp = round_down(sp - sizeof(struct frame_record), 16); + user->next_frame = (struct frame_record __user *)sp; + + sp = round_down(sp, 16) - ilp32_sigframe_size(user); + user->sigframe = (struct ilp32_rt_sigframe __user *)sp; + + /* + * Check that we can actually write to the signal frame. + */ + if (!access_ok(VERIFY_WRITE, user->sigframe, sp_top - sp)) + return -EFAULT; + + return 0; +} + + +void ilp32_setup_return(struct pt_regs *regs, struct k_sigaction *ka, + struct ilp32_rt_sigframe_user_layout *user, int usig) +{ + __sigrestore_t sigtramp; + + regs->regs[0] = usig; + regs->sp = (unsigned long)user->sigframe; + regs->regs[29] = (unsigned long)&user->next_frame->fp; + regs->pc = (unsigned long)ka->sa.sa_handler; + + if (ka->sa.sa_flags & SA_RESTORER) + sigtramp = ka->sa.sa_restorer; + else + sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp_ilp32); + + regs->regs[30] = (unsigned long)sigtramp; +} + +int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, + sigset_t *set, struct pt_regs *regs) +{ + struct ilp32_rt_sigframe_user_layout user; + struct ilp32_rt_sigframe __user *frame; + int err = 0; + + if (ilp32_get_sigframe(&user, ksig, regs)) + return 1; + + frame = user.sigframe; + + __put_user_error(0, &frame->uc.uc_flags, err); + __put_user_error(0, &frame->uc.uc_link, err); + + err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp); + err |= ilp32_setup_sigframe(&user, regs, set); + if (err == 0) { + ilp32_setup_return(regs, &ksig->ka, &user, usig); + if (ksig->ka.sa.sa_flags & SA_SIGINFO) { + err = copy_siginfo_to_user32(&frame->info, &ksig->info); + regs->regs[1] = (unsigned long)&frame->info; + regs->regs[2] = (unsigned long)&frame->uc; + } + } + + return err; +} -- cgit v1.2.3