From: guoren@kernel.org
To: guoren@kernel.org, palmer@dabbelt.com, arnd@arndb.de,
anup.patel@wdc.com, gregkh@linuxfoundation.org,
liush@allwinnertech.com, wefu@redhat.com, drew@beagleboard.org,
wangjunqiang@iscas.ac.cn, lazyparser@gmail.com
Cc: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-csky@vger.kernel.org, Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH 12/13] riscv: compat: signal: Add rt_frame implementation
Date: Wed, 22 Dec 2021 00:35:31 +0800 [thread overview]
Message-ID: <20211221163532.2636028-13-guoren@kernel.org> (raw)
In-Reply-To: <20211221163532.2636028-1-guoren@kernel.org>
From: Guo Ren <guoren@linux.alibaba.com>
Implement compat_setup_rt_frame for sigcontext save & restore. The
main process is the same with signal, but the rv32 pt_regs' size
is different from rv64's, so we needs convert them.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
arch/riscv/kernel/compat_signal.c | 225 ++++++++++++++++++++++++++++++
arch/riscv/kernel/signal.c | 13 +-
2 files changed, 237 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/compat_signal.c b/arch/riscv/kernel/compat_signal.c
index 1ad3d348f37c..7041742ded08 100644
--- a/arch/riscv/kernel/compat_signal.c
+++ b/arch/riscv/kernel/compat_signal.c
@@ -12,7 +12,232 @@
#include <asm/switch_to.h>
#include <asm/csr.h>
+#define COMPAT_DEBUG_SIG 0
+
+struct compat_sigcontext {
+ struct compat_user_regs_struct sc_regs;
+ union __riscv_fp_state sc_fpregs;
+};
+
+struct compat_ucontext {
+ compat_ulong_t uc_flags;
+ struct compat_ucontext *uc_link;
+ compat_stack_t uc_stack;
+ sigset_t uc_sigmask;
+ /* There's some padding here to allow sigset_t to be expanded in the
+ * future. Though this is unlikely, other architectures put uc_sigmask
+ * at the end of this structure and explicitly state it can be
+ * expanded, so we didn't want to box ourselves in here. */
+ __u8 __unused[1024 / 8 - sizeof(sigset_t)];
+ /* We can't put uc_sigmask at the end of this structure because we need
+ * to be able to expand sigcontext in the future. For example, the
+ * vector ISA extension will almost certainly add ISA state. We want
+ * to ensure all user-visible ISA state can be saved and restored via a
+ * ucontext, so we're putting this at the end in order to allow for
+ * infinite extensibility. Since we know this will be extended and we
+ * assume sigset_t won't be extended an extreme amount, we're
+ * prioritizing this. */
+ struct compat_sigcontext uc_mcontext;
+};
+
+struct compat_rt_sigframe {
+ struct compat_siginfo info;
+ struct compat_ucontext uc;
+};
+
+#ifdef CONFIG_FPU
+static long compat_restore_fp_state(struct pt_regs *regs,
+ union __riscv_fp_state __user *sc_fpregs)
+{
+ long err;
+ struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+ size_t i;
+
+ err = __copy_from_user(¤t->thread.fstate, state, sizeof(*state));
+ if (unlikely(err))
+ return err;
+
+ fstate_restore(current, regs);
+
+ /* We support no other extension state at this time. */
+ for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+ u32 value;
+
+ err = __get_user(value, &sc_fpregs->q.reserved[i]);
+ if (unlikely(err))
+ break;
+ if (value != 0)
+ return -EINVAL;
+ }
+
+ return err;
+}
+
+static long compat_save_fp_state(struct pt_regs *regs,
+ union __riscv_fp_state __user *sc_fpregs)
+{
+ long err;
+ struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+ size_t i;
+
+ fstate_save(current, regs);
+ err = __copy_to_user(state, ¤t->thread.fstate, sizeof(*state));
+ if (unlikely(err))
+ return err;
+
+ /* We support no other extension state at this time. */
+ for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+ err = __put_user(0, &sc_fpregs->q.reserved[i]);
+ if (unlikely(err))
+ break;
+ }
+
+ return err;
+}
+#else
+#define compat_save_fp_state(task, regs) (0)
+#define compat_restore_fp_state(task, regs) (0)
+#endif
+
+static long compat_restore_sigcontext(struct pt_regs *regs,
+ struct compat_sigcontext __user *sc)
+{
+ long err;
+ struct compat_user_regs_struct cregs;
+
+ /* sc_regs is structured the same as the start of pt_regs */
+ err = __copy_from_user(&cregs, &sc->sc_regs, sizeof(sc->sc_regs));
+
+ cregs_to_regs(&cregs, regs);
+
+ /* Restore the floating-point state. */
+ if (has_fpu())
+ err |= compat_restore_fp_state(regs, &sc->sc_fpregs);
+ return err;
+}
+
COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
{
+ struct pt_regs *regs = current_pt_regs();
+ struct compat_rt_sigframe __user *frame;
+ struct task_struct *task;
+ sigset_t set;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ frame = (struct compat_rt_sigframe __user *)regs->sp;
+
+ if (!access_ok(frame, sizeof(*frame)))
+ goto badframe;
+
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (compat_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ if (compat_restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return regs->a0;
+
+badframe:
+ task = current;
+ if (show_unhandled_signals) {
+ pr_info_ratelimited(
+ "%s[%d]: bad frame in %s: frame=%p pc=%p sp=%p\n",
+ task->comm, task_pid_nr(task), __func__,
+ frame, (void *)regs->epc, (void *)regs->sp);
+ }
+ force_sig(SIGSEGV);
+ return 0;
+}
+
+static long compat_setup_sigcontext(struct compat_rt_sigframe __user *frame,
+ struct pt_regs *regs)
+{
+ struct compat_sigcontext __user *sc = &frame->uc.uc_mcontext;
+ struct compat_user_regs_struct cregs;
+ long err;
+
+ regs_to_cregs(&cregs, regs);
+
+ /* sc_regs is structured the same as the start of pt_regs */
+ err = __copy_to_user(&sc->sc_regs, &cregs, sizeof(sc->sc_regs));
+ /* Save the floating-point state. */
+ if (has_fpu())
+ err |= compat_save_fp_state(regs, &sc->sc_fpregs);
+ return err;
+}
+
+static inline void __user *compat_get_sigframe(struct ksignal *ksig,
+ struct pt_regs *regs, size_t framesize)
+{
+ unsigned long sp;
+ /* Default to using normal stack */
+ sp = regs->sp;
+
+ /*
+ * If we are on the alternate signal stack and would overflow it, don't.
+ * Return an always-bogus address instead so we will die with SIGSEGV.
+ */
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+ return (void __user __force *)(-1UL);
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ sp = sigsp(sp, ksig) - framesize;
+
+ /* Align the stack frame. */
+ sp &= ~0xfUL;
+
+ return (void __user *)sp;
+}
+
+int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct compat_rt_sigframe __user *frame;
+ long err = 0;
+
+ frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(frame, sizeof(*frame)))
+ return -EFAULT;
+
+ err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(NULL, &frame->uc.uc_link);
+ err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
+ err |= compat_setup_sigcontext(frame, regs);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ return -EFAULT;
+
+ regs->ra = (unsigned long)COMPAT_VDSO_SYMBOL(
+ current->mm->context.vdso, rt_sigreturn);
+
+ /*
+ * Set up registers for signal handler.
+ * Registers that we don't modify keep the value they had from
+ * user-space at the time we took the signal.
+ * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+ * since some things rely on this (e.g. glibc's debug/segfault.c).
+ */
+ regs->epc = (unsigned long)ksig->ka.sa.sa_handler;
+ regs->sp = (unsigned long)frame;
+ regs->a0 = ksig->sig; /* a0: signal number */
+ regs->a1 = (unsigned long)(&frame->info); /* a1: siginfo pointer */
+ regs->a2 = (unsigned long)(&frame->uc); /* a2: ucontext pointer */
+
+#if COMPAT_DEBUG_SIG
+ pr_info("SIG deliver (%s:%d): sig=%d pc=%p ra=%p sp=%p\n",
+ current->comm, task_pid_nr(current), ksig->sig,
+ (void *)regs->epc, (void *)regs->ra, frame);
+#endif
+
return 0;
}
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index c2d5ecbe5526..27d8f39228c4 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -6,6 +6,7 @@
* Copyright (C) 2012 Regents of the University of California
*/
+#include <linux/compat.h>
#include <linux/signal.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
@@ -229,6 +230,11 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
return 0;
}
+#ifdef CONFIG_COMPAT
+extern int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs);
+#endif
+
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
@@ -258,8 +264,13 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
}
}
+#ifdef CONFIG_COMPAT
/* Set up the stack frame */
- ret = setup_rt_frame(ksig, oldset, regs);
+ if (is_compat_task())
+ ret = compat_setup_rt_frame(ksig, oldset, regs);
+ else
+#endif
+ ret = setup_rt_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, 0);
}
--
2.25.1
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next prev parent reply other threads:[~2021-12-21 16:36 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-21 16:35 [PATCH 00/13] riscv: compat: Add COMPAT mode support for rv64 guoren
2021-12-21 16:35 ` [PATCH 01/13] syscalls: compat: Fix the missing part for __SYSCALL_COMPAT guoren
2021-12-21 17:08 ` Arnd Bergmann
2021-12-22 11:16 ` Guo Ren
2021-12-22 11:24 ` Arnd Bergmann
2021-12-24 6:52 ` Christoph Hellwig
2021-12-21 16:35 ` [PATCH 02/13] riscv: Fixup difference with defconfig guoren
2021-12-21 17:09 ` Arnd Bergmann
2021-12-22 11:34 ` Guo Ren
2021-12-22 11:44 ` Arnd Bergmann
2021-12-22 13:06 ` Guo Ren
2021-12-22 13:30 ` Arnd Bergmann
2021-12-23 2:12 ` Guo Ren
2021-12-21 16:35 ` [PATCH 03/13] riscv: compat: Add basic compat date type implementation guoren
2021-12-21 17:12 ` Arnd Bergmann
2021-12-22 12:03 ` Guo Ren
2021-12-22 12:46 ` Arnd Bergmann
2021-12-26 15:33 ` Guo Ren
2021-12-24 6:53 ` Christoph Hellwig
2021-12-24 9:28 ` Guo Ren
2021-12-21 16:35 ` [PATCH 04/13] riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT guoren
2021-12-21 16:35 ` [PATCH 05/13] riscv: compat: syscall: Add compat_sys_call_table implementation guoren
2021-12-21 17:15 ` Arnd Bergmann
2021-12-22 12:43 ` Guo Ren
2021-12-22 13:21 ` Arnd Bergmann
2021-12-22 14:00 ` Arnd Bergmann
2021-12-24 9:42 ` Guo Ren
2021-12-21 16:35 ` [PATCH 06/13] riscv: compat: syscall: Add entry.S implementation guoren
2021-12-21 16:35 ` [PATCH 07/13] riscv: compat: Add elf.h implementation guoren
2021-12-21 16:35 ` [PATCH 08/13] riscv: compat: Add COMPAT Kbuild skeletal support guoren
2021-12-21 17:21 ` Arnd Bergmann
2021-12-22 12:06 ` Guo Ren
2021-12-24 6:54 ` Christoph Hellwig
2021-12-21 16:35 ` [PATCH 09/13] riscv: compat: init: Add hw-cap detect in setup_arch guoren
2021-12-21 16:35 ` [PATCH 10/13] riscv: compat: vdso: Add rv32 VDSO base code implementation guoren
2021-12-21 16:35 ` [PATCH 11/13] riscv: compat: vdso: Add setup additional pages implementation guoren
2021-12-21 16:35 ` guoren [this message]
2021-12-21 16:35 ` [PATCH 13/13] riscv: compat: ptrace: Add compat_arch_ptrace implement guoren
2021-12-21 17:38 ` [PATCH 00/13] riscv: compat: Add COMPAT mode support for rv64 Arnd Bergmann
2021-12-22 12:59 ` Guo Ren
2021-12-22 13:29 ` Arnd Bergmann
2021-12-26 8:22 ` Jisheng Zhang
2021-12-26 12:38 ` Guo Ren
2021-12-26 20:31 ` Arnd Bergmann
2021-12-27 1:16 ` Guo Ren
2021-12-27 2:29 ` Jessica Clarke
2021-12-28 10:45 ` Guo Ren
2021-12-22 12:00 ` Guo Ren
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