From: Andrew Pinski <apinski@xxxxxxxxxx> 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: Andrew Pinski <Andrew.Pinski@xxxxxxxxxxxxxxxxxx> Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> --- arch/arm64/include/asm/signal_ilp32.h | 38 ++++++++ arch/arm64/kernel/Makefile | 3 +- arch/arm64/kernel/entry_ilp32.S | 23 +++++ arch/arm64/kernel/signal.c | 3 + arch/arm64/kernel/signal_ilp32.c | 171 ++++++++++++++++++++++++++++++++++ 5 files changed, 237 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 0000000..3c6d737 --- /dev/null +++ b/arch/arm64/include/asm/signal_ilp32.h @@ -0,0 +1,38 @@ +/* + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <asm/signal32_common.h> +#include <asm/signal_common.h> + +#ifndef __ASM_SIGNAL_ILP32_H +#define __ASM_SIGNAL_ILP32_H + +#ifdef CONFIG_ARM64_ILP32 + +#include <linux/compat.h> + +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 20e8e66..7038ffb 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -27,7 +27,8 @@ $(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 0000000..5063172 --- /dev/null +++ b/arch/arm64/kernel/entry_ilp32.S @@ -0,0 +1,23 @@ +/* + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <linux/linkage.h> + +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 5c73864..241bfeb 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -35,6 +35,7 @@ #include <asm/signal32.h> #include <asm/vdso.h> #include <asm/signal_common.h> +#include <asm/signal_ilp32.h> #define RT_SIGFRAME_FP_POS (offsetof(struct rt_sigframe, sig) \ + offsetof(struct sigframe, fp)) @@ -325,6 +326,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) ret = compat_setup_rt_frame(usig, ksig, oldset, regs); else ret = compat_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 0000000..7cc9122 --- /dev/null +++ b/arch/arm64/kernel/signal_ilp32.c @@ -0,0 +1,171 @@ +/* + * Based on arch/arm/kernel/signal.c + * + * Copyright (C) 1995-2009 Russell King + * Copyright (C) 2012 ARM Ltd. + * Copyright (C) 2016 Cavium Networks. + * Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <linux/compat.h> +#include <linux/signal.h> +#include <linux/syscalls.h> +#include <linux/ratelimit.h> + +#include <asm/esr.h> +#include <asm/fpsimd.h> +#include <asm/signal_ilp32.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> +#include <asm/ucontext.h> + + +#define ILP32_RT_SIGFRAME_FP_POS (offsetof(struct ilp32_rt_sigframe, sig) \ + + offsetof(struct ilp32_sigframe, fp)) + +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_sigframe { + struct ilp32_ucontext uc; + u64 fp; + u64 lr; +}; + +struct ilp32_rt_sigframe { + struct compat_siginfo info; + struct ilp32_sigframe sig; +}; + +static int restore_ilp32_sigframe(struct pt_regs *regs, + struct ilp32_sigframe __user *sf) +{ + sigset_t set; + int err; + err = get_sigset_t(&set, &sf->uc.uc_sigmask); + if (err == 0) + set_current_blocked(&set); + err |= restore_sigcontext(regs, &sf->uc.uc_mcontext); + return err; +} + +static int setup_ilp32_sigframe(struct ilp32_sigframe __user *sf, + struct pt_regs *regs, sigset_t *set) +{ + int err = 0; + /* set up the stack frame for unwinding */ + __put_user_error(regs->regs[29], &sf->fp, err); + __put_user_error(regs->regs[30], &sf->lr, err); + + err |= put_sigset_t(&sf->uc.uc_sigmask, set); + err |= setup_sigcontext(&sf->uc.uc_mcontext, regs); + 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 it's + * not, then the user is trying to mess with us. + */ + 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 (restore_ilp32_sigframe(regs, &frame->sig)) + goto badframe; + + if (compat_restore_altstack(&frame->sig.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 struct ilp32_rt_sigframe __user *ilp32_get_sigframe(struct ksignal *ksig, + struct pt_regs *regs) +{ + unsigned long sp, sp_top; + struct ilp32_rt_sigframe __user *frame; + + sp = sp_top = sigsp(regs->sp, ksig); + + sp = (sp - sizeof(struct ilp32_rt_sigframe)) & ~15; + frame = (struct ilp32_rt_sigframe __user *)sp; + + /* + * Check that we can actually write to the signal frame. + */ + if (!access_ok(VERIFY_WRITE, frame, sp_top - sp)) + frame = NULL; + + return frame; +} + +/* + * ILP32 signal handling routines called from signal.c + */ +int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, + sigset_t *set, struct pt_regs *regs) +{ + struct ilp32_rt_sigframe __user *frame; + int err = 0; + + frame = ilp32_get_sigframe(ksig, regs); + + if (!frame) + return 1; + + err |= copy_siginfo_to_user32(&frame->info, &ksig->info); + + __put_user_error(0, &frame->sig.uc.uc_flags, err); + __put_user_error(0, &frame->sig.uc.uc_link, err); + + err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->sp); + err |= setup_ilp32_sigframe(&frame->sig, regs, set); + if (err == 0) { + setup_return(regs, &ksig->ka, frame, ILP32_RT_SIGFRAME_FP_POS, usig); + regs->regs[1] = (unsigned long)&frame->info; + regs->regs[2] = (unsigned long)&frame->sig.uc; + } + + return err; +} + -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
