From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/riscv/kernel/signal.c | 158 +++++++++++++++++++++++++++++++---------------------
1 files changed, 93 insertions(+), 65 deletions(-)
diff --git a/kernel/arch/riscv/kernel/signal.c b/kernel/arch/riscv/kernel/signal.c
index 718d0c9..50a8225 100644
--- a/kernel/arch/riscv/kernel/signal.c
+++ b/kernel/arch/riscv/kernel/signal.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Chen Liqin <liqin.chen@sunplusct.com>
* Lennox Wu <lennox.wu@sunplusct.com>
* Copyright (C) 2012 Regents of the University of California
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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 the file COPYING, or write
- * to the Free Software Foundation, Inc.,
*/
#include <linux/signal.h>
@@ -30,52 +17,81 @@
#include <asm/switch_to.h>
#include <asm/csr.h>
+extern u32 __user_rt_sigreturn[2];
+
#define DEBUG_SIG 0
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
+#ifndef CONFIG_MMU
+ u32 sigreturn_code[2];
+#endif
};
-static long restore_d_state(struct pt_regs *regs,
- struct __riscv_d_ext_state __user *state)
+#ifdef CONFIG_FPU
+static long restore_fp_state(struct pt_regs *regs,
+ union __riscv_fp_state __user *sc_fpregs)
{
long err;
- err = __copy_from_user(¤t->thread.fstate, state, sizeof(*state));
- if (likely(!err))
- fstate_restore(current, regs);
- return err;
-}
-
-static long save_d_state(struct pt_regs *regs,
- struct __riscv_d_ext_state __user *state)
-{
- fstate_save(current, regs);
- return __copy_to_user(state, ¤t->thread.fstate, sizeof(*state));
-}
-
-static long restore_sigcontext(struct pt_regs *regs,
- struct sigcontext __user *sc)
-{
- long err;
+ struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
size_t i;
- /* sc_regs is structured the same as the start of pt_regs */
- err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
+
+ err = __copy_from_user(¤t->thread.fstate, state, sizeof(*state));
if (unlikely(err))
return err;
- /* Restore the floating-point state. */
- err = restore_d_state(regs, &sc->sc_fpregs.d);
- 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->sc_fpregs.q.reserved); i++) {
+ for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
u32 value;
- err = __get_user(value, &sc->sc_fpregs.q.reserved[i]);
+
+ err = __get_user(value, &sc_fpregs->q.reserved[i]);
if (unlikely(err))
break;
if (value != 0)
return -EINVAL;
}
+
+ return err;
+}
+
+static long 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 save_fp_state(task, regs) (0)
+#define restore_fp_state(task, regs) (0)
+#endif
+
+static long restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext __user *sc)
+{
+ long err;
+ /* sc_regs is structured the same as the start of pt_regs */
+ err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
+ /* Restore the floating-point state. */
+ if (has_fpu)
+ err |= restore_fp_state(regs, &sc->sc_fpregs);
return err;
}
@@ -91,7 +107,7 @@
frame = (struct rt_sigframe __user *)regs->sp;
- if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ if (!access_ok(frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
@@ -105,6 +121,8 @@
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
+ regs->cause = -1UL;
+
return regs->a0;
badframe:
@@ -113,9 +131,9 @@
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->sepc, (void *)regs->sp);
+ frame, (void *)regs->epc, (void *)regs->sp);
}
- force_sig(SIGSEGV, task);
+ force_sig(SIGSEGV);
return 0;
}
@@ -124,14 +142,11 @@
{
struct sigcontext __user *sc = &frame->uc.uc_mcontext;
long err;
- size_t i;
/* sc_regs is structured the same as the start of pt_regs */
err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
/* Save the floating-point state. */
- err |= save_d_state(regs, &sc->sc_fpregs.d);
- /* We support no other extension state at this time. */
- for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++)
- err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]);
+ if (has_fpu)
+ err |= save_fp_state(regs, &sc->sc_fpregs);
return err;
}
@@ -158,7 +173,6 @@
return (void __user *)sp;
}
-
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
@@ -166,7 +180,7 @@
long err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
- if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ if (!access_ok(frame, sizeof(*frame)))
return -EFAULT;
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
@@ -181,8 +195,19 @@
return -EFAULT;
/* Set up to return from userspace. */
+#ifdef CONFIG_MMU
regs->ra = (unsigned long)VDSO_SYMBOL(
current->mm->context.vdso, rt_sigreturn);
+#else
+ /*
+ * For the nommu case we don't have a VDSO. Instead we push two
+ * instructions to call the rt_sigreturn syscall onto the user stack.
+ */
+ if (copy_to_user(&frame->sigreturn_code, __user_rt_sigreturn,
+ sizeof(frame->sigreturn_code)))
+ return -EFAULT;
+ regs->ra = (unsigned long)&frame->sigreturn_code;
+#endif /* CONFIG_MMU */
/*
* Set up registers for signal handler.
@@ -191,7 +216,7 @@
* We always pass siginfo and mcontext, regardless of SA_SIGINFO,
* since some things rely on this (e.g. glibc's debug/segfault.c).
*/
- regs->sepc = (unsigned long)ksig->ka.sa.sa_handler;
+ 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 */
@@ -200,7 +225,7 @@
#if 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->sepc, (void *)regs->ra, frame);
+ (void *)regs->epc, (void *)regs->ra, frame);
#endif
return 0;
@@ -212,7 +237,9 @@
int ret;
/* Are we from a system call? */
- if (regs->scause == EXC_SYSCALL) {
+ if (regs->cause == EXC_SYSCALL) {
+ /* Avoid additional syscall restarting via ret_from_exception */
+ regs->cause = -1UL;
/* If so, check system call restarting.. */
switch (regs->a0) {
case -ERESTART_RESTARTBLOCK:
@@ -225,10 +252,10 @@
regs->a0 = -EINTR;
break;
}
- /* fallthrough */
+ fallthrough;
case -ERESTARTNOINTR:
regs->a0 = regs->orig_a0;
- regs->sepc -= 0x4;
+ regs->epc -= 0x4;
break;
}
}
@@ -250,19 +277,22 @@
}
/* Did we come from a system call? */
- if (regs->scause == EXC_SYSCALL) {
+ if (regs->cause == EXC_SYSCALL) {
+ /* Avoid additional syscall restarting via ret_from_exception */
+ regs->cause = -1UL;
+
/* Restart the system call - no handlers present */
switch (regs->a0) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->a0 = regs->orig_a0;
- regs->sepc -= 0x4;
+ regs->epc -= 0x4;
break;
case -ERESTART_RESTARTBLOCK:
regs->a0 = regs->orig_a0;
regs->a7 = __NR_restart_syscall;
- regs->sepc -= 0x4;
+ regs->epc -= 0x4;
break;
}
}
@@ -278,15 +308,13 @@
* notification of userspace execution resumption
* - triggered by the _TIF_WORK_MASK flags
*/
-asmlinkage void do_notify_resume(struct pt_regs *regs,
- unsigned long thread_info_flags)
+asmlinkage __visible void do_notify_resume(struct pt_regs *regs,
+ unsigned long thread_info_flags)
{
/* Handle pending signal delivery */
- if (thread_info_flags & _TIF_SIGPENDING)
+ if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
do_signal(regs);
- if (thread_info_flags & _TIF_NOTIFY_RESUME) {
- clear_thread_flag(TIF_NOTIFY_RESUME);
+ if (thread_info_flags & _TIF_NOTIFY_RESUME)
tracehook_notify_resume(regs);
- }
}
--
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