This patch adds signal handling support for LoongArch.
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/include/asm/sigcontext.h | 10 +
arch/loongarch/include/asm/signal.h | 16 +
arch/loongarch/include/uapi/asm/sigcontext.h | 40 ++
arch/loongarch/include/uapi/asm/siginfo.h | 19 +
arch/loongarch/include/uapi/asm/signal.h | 115 ++++
arch/loongarch/include/uapi/asm/ucontext.h | 46 ++
arch/loongarch/kernel/signal-common.h | 52 ++
arch/loongarch/kernel/signal.c | 583 +++++++++++++++++++
8 files changed, 881 insertions(+)
create mode 100644 arch/loongarch/include/asm/sigcontext.h
create mode 100644 arch/loongarch/include/asm/signal.h
create mode 100644 arch/loongarch/include/uapi/asm/sigcontext.h
create mode 100644 arch/loongarch/include/uapi/asm/siginfo.h
create mode 100644 arch/loongarch/include/uapi/asm/signal.h
create mode 100644 arch/loongarch/include/uapi/asm/ucontext.h
create mode 100644 arch/loongarch/kernel/signal-common.h
create mode 100644 arch/loongarch/kernel/signal.c
diff --git a/arch/loongarch/include/asm/sigcontext.h b/arch/loongarch/include/asm/sigcontext.h
new file mode 100644
index 000000000000..c8d46213ad98
--- /dev/null
+++ b/arch/loongarch/include/asm/sigcontext.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_SIGCONTEXT_H
+#define _ASM_SIGCONTEXT_H
+
+#include <uapi/asm/sigcontext.h>
+
+#endif /* _ASM_SIGCONTEXT_H */
diff --git a/arch/loongarch/include/asm/signal.h b/arch/loongarch/include/asm/signal.h
new file mode 100644
index 000000000000..530805184ce5
--- /dev/null
+++ b/arch/loongarch/include/asm/signal.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_SIGNAL_H
+#define _ASM_SIGNAL_H
+
+#include <uapi/asm/signal.h>
+
+#ifndef __ASSEMBLY__
+
+#include <asm/sigcontext.h>
+#undef __HAVE_ARCH_SIG_BITOPS
+
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_SIGNAL_H */
diff --git a/arch/loongarch/include/uapi/asm/sigcontext.h b/arch/loongarch/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000000..da0e5bac2d80
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/sigcontext.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _UAPI_ASM_SIGCONTEXT_H
+#define _UAPI_ASM_SIGCONTEXT_H
+
+#include <linux/types.h>
+#include <asm/processor.h>
+
+/* scalar FP context was used */
+#define USED_FP (1 << 0)
+
+/* extended context was used, see struct extcontext for details */
+#define USED_EXTCONTEXT (1 << 1)
+
+#include <linux/posix_types.h>
+/*
+ * Keep this struct definition in sync with the sigcontext fragment
+ * in arch/loongarch/kernel/asm-offsets.c
+ *
+ */
+struct sigcontext {
+ __u64 sc_pc;
+ __u64 sc_regs[32];
+ __u32 sc_flags;
+
+ __u32 sc_fcsr;
+ __u32 sc_vcsr;
+ __u64 sc_fcc;
+ __u64 sc_scr[4];
+
+ union fpureg sc_fpregs[32] FPU_ALIGN;
+ __u8 sc_reserved[4096] __attribute__((__aligned__(16)));
+};
+
+#endif /* _UAPI_ASM_SIGCONTEXT_H */
diff --git a/arch/loongarch/include/uapi/asm/siginfo.h b/arch/loongarch/include/uapi/asm/siginfo.h
new file mode 100644
index 000000000000..11287ad78138
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/siginfo.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _UAPI_ASM_SIGINFO_H
+#define _UAPI_ASM_SIGINFO_H
+
+#if _LOONGARCH_SZLONG == 32
+#define __ARCH_SI_PREAMBLE_SIZE (3 * sizeof(int))
+#else
+#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
+#endif
+
+#include <asm-generic/siginfo.h>
+
+#endif /* _UAPI_ASM_SIGINFO_H */
diff --git a/arch/loongarch/include/uapi/asm/signal.h b/arch/loongarch/include/uapi/asm/signal.h
new file mode 100644
index 000000000000..2254aef35402
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/signal.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _UAPI_ASM_SIGNAL_H
+#define _UAPI_ASM_SIGNAL_H
+
+#include <linux/types.h>
+
+#ifndef _NSIG
+#define _NSIG 128
+#endif
+#define _NSIG_BPW __BITS_PER_LONG
+#define _NSIG_WORDS (_NSIG / _NSIG_BPW)
+
+#define SIGHUP 1
+#define SIGINT 2
+#define SIGQUIT 3
+#define SIGILL 4
+#define SIGTRAP 5
+#define SIGABRT 6
+#define SIGIOT 6
+#define SIGBUS 7
+#define SIGFPE 8
+#define SIGKILL 9
+#define SIGUSR1 10
+#define SIGSEGV 11
+#define SIGUSR2 12
+#define SIGPIPE 13
+#define SIGALRM 14
+#define SIGTERM 15
+#define SIGSTKFLT 16
+#define SIGCHLD 17
+#define SIGCONT 18
+#define SIGSTOP 19
+#define SIGTSTP 20
+#define SIGTTIN 21
+#define SIGTTOU 22
+#define SIGURG 23
+#define SIGXCPU 24
+#define SIGXFSZ 25
+#define SIGVTALRM 26
+#define SIGPROF 27
+#define SIGWINCH 28
+#define SIGIO 29
+#define SIGPOLL SIGIO
+#define SIGPWR 30
+#define SIGSYS 31
+#define SIGUNUSED 31
+
+/* These should not be considered constants from userland. */
+#define SIGRTMIN 32
+#ifndef SIGRTMAX
+#define SIGRTMAX _NSIG
+#endif
+
+/*
+ * SA_FLAGS values:
+ *
+ * SA_ONSTACK indicates that a registered stack_t will be used.
+ * SA_RESTART flag to get restarting signals (which were the default long ago)
+ * SA_NOCLDSTOP flag to turn off SIGCHLD when children stop.
+ * SA_RESETHAND clears the handler when the signal is delivered.
+ * SA_NOCLDWAIT flag on SIGCHLD to inhibit zombies.
+ * SA_NODEFER prevents the current signal from being masked in the handler.
+ *
+ * SA_ONESHOT and SA_NOMASK are the historical Linux names for the Single
+ * Unix names RESETHAND and NODEFER respectively.
+ */
+#define SA_NOCLDSTOP 0x00000001
+#define SA_NOCLDWAIT 0x00000002
+#define SA_SIGINFO 0x00000004
+#define SA_ONSTACK 0x08000000
+#define SA_RESTART 0x10000000
+#define SA_NODEFER 0x40000000
+#define SA_RESETHAND 0x80000000
+
+#define SA_NOMASK SA_NODEFER
+#define SA_ONESHOT SA_RESETHAND
+
+#if !defined MINSIGSTKSZ || !defined SIGSTKSZ
+#define MINSIGSTKSZ 2048
+#define SIGSTKSZ 8192
+#endif
+
+#ifndef __ASSEMBLY__
+typedef struct {
+ unsigned long sig[_NSIG_WORDS];
+} sigset_t;
+
+/* not actually used, but required for linux/syscalls.h */
+typedef unsigned long old_sigset_t;
+
+#include <asm-generic/signal-defs.h>
+
+#ifndef __KERNEL__
+struct sigaction {
+ __sighandler_t sa_handler;
+ unsigned long sa_flags;
+ sigset_t sa_mask; /* mask last for extensibility */
+};
+#endif
+
+typedef struct sigaltstack {
+ void __user *ss_sp;
+ int ss_flags;
+ size_t ss_size;
+} stack_t;
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _UAPI_ASM_SIGNAL_H */
diff --git a/arch/loongarch/include/uapi/asm/ucontext.h b/arch/loongarch/include/uapi/asm/ucontext.h
new file mode 100644
index 000000000000..e3814b5fbce8
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/ucontext.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __LOONGARCH_UAPI_ASM_UCONTEXT_H
+#define __LOONGARCH_UAPI_ASM_UCONTEXT_H
+
+/**
+ * struct extcontext - extended context header structure
+ * @magic: magic value identifying the type of extended context
+ * @size: the size in bytes of the enclosing structure
+ *
+ * Extended context structures provide context which does not fit within struct
+ * sigcontext. They are placed sequentially in memory at the end of struct
+ * ucontext and struct sigframe, with each extended context structure beginning
+ * with a header defined by this struct. The type of context represented is
+ * indicated by the magic field. Userland may check each extended context
+ * structure against magic values that it recognises. The size field allows any
+ * unrecognised context to be skipped, allowing for future expansion. The end
+ * of the extended context data is indicated by the magic value
+ * END_EXTCONTEXT_MAGIC.
+ */
+struct extcontext {
+ unsigned int magic;
+ unsigned int size;
+};
+
+/**
+ * struct ucontext - user context structure
+ * @uc_flags:
+ * @uc_link:
+ * @uc_stack:
+ * @uc_mcontext: holds basic processor state
+ * @uc_sigmask:
+ * @uc_extcontext: holds extended processor state
+ */
+struct ucontext {
+ /* Historic fields matching asm-generic */
+ unsigned long uc_flags;
+ struct ucontext *uc_link;
+ stack_t uc_stack;
+ struct sigcontext uc_mcontext;
+ sigset_t uc_sigmask;
+
+ /* Extended context structures may follow ucontext */
+ unsigned long long uc_extcontext[0];
+};
+
+#endif /* __LOONGARCH_UAPI_ASM_UCONTEXT_H */
diff --git a/arch/loongarch/kernel/signal-common.h b/arch/loongarch/kernel/signal-common.h
new file mode 100644
index 000000000000..c0ce90f988e5
--- /dev/null
+++ b/arch/loongarch/kernel/signal-common.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef __SIGNAL_COMMON_H
+#define __SIGNAL_COMMON_H
+
+/* #define DEBUG_SIG */
+
+#ifdef DEBUG_SIG
+# define DEBUGP(fmt, args...) printk("%s: " fmt, __func__, ##args)
+#else
+# define DEBUGP(fmt, args...)
+#endif
+
+/*
+ * Determine which stack to use..
+ */
+extern void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+ size_t frame_size);
+/* Check and clear pending FPU exceptions in saved CSR */
+extern int fpcsr_pending(unsigned int __user *fpcsr);
+
+/* Make sure we will not lose FPU ownership */
+#define lock_fpu_owner() ({ preempt_disable(); pagefault_disable(); })
+#define unlock_fpu_owner() ({ pagefault_enable(); preempt_enable(); })
+
+/* Assembly functions to move context to/from the FPU */
+extern asmlinkage int
+_save_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
+extern asmlinkage int
+_restore_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
+extern asmlinkage int
+_save_lsx_context(void __user *fpregs, void __user *fcc, void __user *fcsr,
+ void __user *vcsr);
+extern asmlinkage int
+_restore_lsx_context(void __user *fpregs, void __user *fcc, void __user *fcsr,
+ void __user *vcsr);
+extern asmlinkage int
+_save_lasx_context(void __user *fpregs, void __user *fcc, void __user *fcsr,
+ void __user *vcsr);
+extern asmlinkage int
+_restore_lasx_context(void __user *fpregs, void __user *fcc, void __user *fcsr,
+ void __user *vcsr);
+extern asmlinkage int _save_lsx_all_upper(void __user *buf);
+extern asmlinkage int _restore_lsx_all_upper(void __user *buf);
+
+#endif /* __SIGNAL_COMMON_H */
diff --git a/arch/loongarch/kernel/signal.c b/arch/loongarch/kernel/signal.c
new file mode 100644
index 000000000000..b722b9e7c380
--- /dev/null
+++ b/arch/loongarch/kernel/signal.c
@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/audit.h>
+#include <linux/cache.h>
+#include <linux/context_tracking.h>
+#include <linux/irqflags.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/personality.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/uprobes.h>
+#include <linux/compiler.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <linux/tracehook.h>
+
+#include <asm/abi.h>
+#include <asm/asm.h>
+#include <asm/cacheflush.h>
+#include <asm/fpu.h>
+#include <asm/ucontext.h>
+#include <asm/cpu-features.h>
+#include <asm/inst.h>
+
+#include "signal-common.h"
+
+static int (*save_fp_context)(void __user *sc);
+static int (*restore_fp_context)(void __user *sc);
+
+struct sigframe {
+ u32 sf_ass[4]; /* argument save space for o32 */
+ u32 sf_pad[2]; /* Was: signal trampoline */
+
+ /* Matches struct ucontext from its uc_mcontext field onwards */
+ struct sigcontext sf_sc;
+ sigset_t sf_mask;
+ unsigned long long sf_extcontext[0];
+};
+
+struct rt_sigframe {
+ u32 rs_ass[4]; /* argument save space for o32 */
+ u32 rs_pad[2]; /* Was: signal trampoline */
+ struct siginfo rs_info;
+ struct ucontext rs_uc;
+};
+
+/*
+ * Thread saved context copy to/from a signal context presumed to be on the
+ * user stack, and therefore accessed with appropriate macros from uaccess.h.
+ */
+static int copy_fp_to_sigcontext(void __user *sc)
+{
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint64_t __user *fcc = sc + abi->off_sc_fcc;
+ uint32_t __user *csr = sc + abi->off_sc_fcsr;
+ int i;
+ int err = 0;
+ int inc = 1;
+
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
+ err |=
+ __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
+ &fpregs[4*i]);
+ }
+ err |= __put_user(current->thread.fpu.fcsr, csr);
+ err |= __put_user(current->thread.fpu.fcc, fcc);
+
+ return err;
+}
+
+static int copy_fp_from_sigcontext(void __user *sc)
+{
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint64_t __user *fcc = sc + abi->off_sc_fcc;
+ uint32_t __user *csr = sc + abi->off_sc_fcsr;
+ int i;
+ int err = 0;
+ int inc = 1;
+ u64 fpr_val;
+
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
+ err |= __get_user(fpr_val, &fpregs[4*i]);
+ set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
+ }
+ err |= __get_user(current->thread.fpu.fcsr, csr);
+ err |= __get_user(current->thread.fpu.fcc, fcc);
+
+ return err;
+}
+
+/*
+ * Wrappers for the assembly _{save,restore}_fp_context functions.
+ */
+static int save_hw_fp_context(void __user *sc)
+{
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint64_t __user *fcc = sc + abi->off_sc_fcc;
+ uint32_t __user *fcsr = sc + abi->off_sc_fcsr;
+
+ return _save_fp_context(fpregs, fcc, fcsr);
+}
+
+static int restore_hw_fp_context(void __user *sc)
+{
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint64_t __user *fcc = sc + abi->off_sc_fcc;
+ uint32_t __user *csr = sc + abi->off_sc_fcsr;
+
+ return _restore_fp_context(fpregs, fcc, csr);
+}
+
+/*
+ * Extended context handling.
+ */
+
+static inline void __user *sc_to_extcontext(void __user *sc)
+{
+ struct ucontext __user *uc;
+
+ /*
+ * We can just pretend the sigcontext is always embedded in a struct
+ * ucontext here, because the offset from sigcontext to extended
+ * context is the same in the struct sigframe case.
+ */
+ uc = container_of(sc, struct ucontext, uc_mcontext);
+ return &uc->uc_extcontext;
+}
+
+static int save_extcontext(void __user *buf)
+{
+ return 0;
+}
+
+static int restore_extcontext(void __user *buf)
+{
+ return 0;
+}
+
+/*
+ * Helper routines
+ */
+int protected_save_fp_context(void __user *sc)
+{
+ int err = 0;
+ unsigned int used, ext_sz;
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *fcc = sc + abi->off_sc_fcsr;
+ uint32_t __user *fcsr = sc + abi->off_sc_fcsr;
+ uint32_t __user *vcsr = sc + abi->off_sc_vcsr;
+ uint32_t __user *flags = sc + abi->off_sc_flags;
+
+ used = used_math() ? USED_FP : 0;
+ if (!used)
+ goto fp_done;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner())
+ err = save_fp_context(sc);
+ else
+ err |= copy_fp_to_sigcontext(sc);
+ unlock_fpu_owner();
+ if (likely(!err))
+ break;
+ /* touch the sigcontext and try again */
+ err = __put_user(0, &fpregs[0]) |
+ __put_user(0, &fpregs[31*4]) |
+ __put_user(0, fcc) |
+ __put_user(0, fcsr) |
+ __put_user(0, vcsr);
+ if (err)
+ return err; /* really bad sigcontext */
+ }
+
+fp_done:
+ ext_sz = err = save_extcontext(sc_to_extcontext(sc));
+ if (err < 0)
+ return err;
+ used |= ext_sz ? USED_EXTCONTEXT : 0;
+
+ return __put_user(used, flags);
+}
+
+int protected_restore_fp_context(void __user *sc)
+{
+ unsigned int used;
+ int err = 0, sig = 0, tmp __maybe_unused;
+ struct loongarch_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *fcsr = sc + abi->off_sc_fcsr;
+ uint32_t __user *fcc = sc + abi->off_sc_fcsr;
+ uint32_t __user *vcsr = sc + abi->off_sc_vcsr;
+ uint32_t __user *flags = sc + abi->off_sc_flags;
+
+ err = __get_user(used, flags);
+ conditional_used_math(used & USED_FP);
+
+ /*
+ * The signal handler may have used FPU; give it up if the program
+ * doesn't want it following sigreturn.
+ */
+ if (err || !(used & USED_FP))
+ lose_fpu(0);
+
+ if (err)
+ return err;
+
+ if (!(used & USED_FP))
+ goto fp_done;
+
+ err = sig = fpcsr_pending(fcsr);
+ if (err < 0)
+ return err;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner())
+ err = restore_fp_context(sc);
+ else
+ err |= copy_fp_from_sigcontext(sc);
+ unlock_fpu_owner();
+ if (likely(!err))
+ break;
+ /* touch the sigcontext and try again */
+ err = __get_user(tmp, &fpregs[0]) |
+ __get_user(tmp, &fpregs[31*4]) |
+ __get_user(tmp, fcc) |
+ __get_user(tmp, fcsr) |
+ __get_user(tmp, vcsr);
+ if (err)
+ break; /* really bad sigcontext */
+ }
+
+fp_done:
+ if (!err && (used & USED_EXTCONTEXT))
+ err = restore_extcontext(sc_to_extcontext(sc));
+
+ return err ?: sig;
+}
+
+int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+ int i;
+
+ err |= __put_user(regs->csr_epc, &sc->sc_pc);
+
+ err |= __put_user(0, &sc->sc_regs[0]);
+ for (i = 1; i < 32; i++)
+ err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
+
+ /*
+ * Save FPU state to signal context. Signal handler
+ * will "inherit" current FPU state.
+ */
+ err |= protected_save_fp_context(sc);
+
+ return err;
+}
+
+static size_t extcontext_max_size(void)
+{
+ size_t sz = 0;
+
+ /*
+ * The assumption here is that between this point & the point at which
+ * the extended context is saved the size of the context should only
+ * ever be able to shrink (if the task is preempted), but never grow.
+ * That is, what this function returns is an upper bound on the size of
+ * the extended context for the current task at the current time.
+ */
+
+ /* If any context is saved then we'll append the end marker */
+ if (sz)
+ sz += sizeof(((struct extcontext *)NULL)->magic);
+
+ return sz;
+}
+
+int fpcsr_pending(unsigned int __user *fpcsr)
+{
+ int err, sig = 0;
+ unsigned int csr, enabled;
+
+ err = __get_user(csr, fpcsr);
+ enabled = ((csr & FPU_CSR_ALL_E) << 24);
+ /*
+ * If the signal handler set some FPU exceptions, clear it and
+ * send SIGFPE.
+ */
+ if (csr & enabled) {
+ csr &= ~enabled;
+ err |= __put_user(csr, fpcsr);
+ sig = SIGFPE;
+ }
+ return err ?: sig;
+}
+
+int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+ int i;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ err |= __get_user(regs->csr_epc, &sc->sc_pc);
+
+ for (i = 1; i < 32; i++)
+ err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
+
+ return err ?: protected_restore_fp_context(sc);
+}
+
+void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+ size_t frame_size)
+{
+ unsigned long sp;
+
+ /* Leave space for potential extended context */
+ frame_size += extcontext_max_size();
+
+ /* Default to using normal stack */
+ sp = regs->regs[3];
+
+ /*
+ * FPU emulator may have it's own trampoline active just
+ * above the user stack, 16-bytes before the next lowest
+ * 16 byte boundary. Try to avoid trashing it.
+ */
+ sp -= 32;
+
+ sp = sigsp(sp, ksig);
+
+ return (void __user *)((sp - frame_size) & ALMASK);
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+asmlinkage void sys_rt_sigreturn(void)
+{
+ struct rt_sigframe __user *frame;
+ struct pt_regs *regs;
+ sigset_t set;
+ int sig;
+
+ regs = current_pt_regs();
+ frame = (struct rt_sigframe __user *)regs->regs[3];
+ if (!access_ok(frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ if (sig < 0)
+ goto badframe;
+ else if (sig)
+ force_sig(sig);
+
+ if (restore_altstack(&frame->rs_uc.uc_stack))
+ goto badframe;
+
+ /*
+ * Don't let your children do this ...
+ */
+ __asm__ __volatile__(
+ "or\t$sp, $zero, %0\n\t"
+ "b\tsyscall_exit"
+ : /* no outputs */
+ : "r" (regs));
+ /* Unreached */
+
+badframe:
+ force_sig(SIGSEGV);
+}
+
+static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
+ struct pt_regs *regs, sigset_t *set)
+{
+ struct rt_sigframe __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(frame, sizeof(*frame)))
+ return -EFAULT;
+
+ /* Create siginfo. */
+ err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->rs_uc.uc_flags);
+ err |= __put_user(NULL, &frame->rs_uc.uc_link);
+ err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[3]);
+ err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
+
+ if (err)
+ return -EFAULT;
+
+ /*
+ * Arguments to signal handler:
+ *
+ * a0 = signal number
+ * a1 = 0 (should be cause)
+ * a2 = pointer to ucontext
+ *
+ * $25 and c0_epc point to the signal handler, $29 points to
+ * the struct rt_sigframe.
+ */
+ regs->regs[4] = ksig->sig;
+ regs->regs[5] = (unsigned long) &frame->rs_info;
+ regs->regs[6] = (unsigned long) &frame->rs_uc;
+ regs->regs[3] = (unsigned long) frame;
+ regs->regs[1] = (unsigned long) sig_return;
+ regs->csr_epc = (unsigned long) ksig->ka.sa.sa_handler;
+
+ DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
+ current->comm, current->pid,
+ frame, regs->csr_epc, regs->regs[1]);
+
+ return 0;
+}
+
+struct loongarch_abi loongarch_abi = {
+ .setup_rt_frame = setup_rt_frame,
+ .restart = __NR_restart_syscall,
+#ifdef CONFIG_32BIT
+ .audit_arch = AUDIT_ARCH_LOONGARCH32,
+#else
+ .audit_arch = AUDIT_ARCH_LOONGARCH64,
+#endif
+
+ .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
+ .off_sc_fcc = offsetof(struct sigcontext, sc_fcc),
+ .off_sc_fcsr = offsetof(struct sigcontext, sc_fcsr),
+ .off_sc_flags = offsetof(struct sigcontext, sc_flags),
+ .off_sc_vcsr = offsetof(struct sigcontext, sc_vcsr),
+
+ .vdso = &vdso_image,
+};
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+ struct loongarch_abi *abi = current->thread.abi;
+ void *vdso = current->mm->context.vdso;
+
+ /* Are we from a system call? */
+ if (regs->regs[0]) {
+ switch (regs->regs[4]) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->regs[4] = -EINTR;
+ break;
+ case -ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->regs[4] = -EINTR;
+ break;
+ }
+ fallthrough;
+ case -ERESTARTNOINTR:
+ regs->regs[4] = regs->orig_a0;
+ regs->csr_epc -= 4;
+ }
+
+ regs->regs[0] = 0; /* Don't deal with this again. */
+ }
+
+ rseq_signal_deliver(ksig, regs);
+
+ ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
+ ksig, regs, oldset);
+
+ signal_setup_done(ret, ksig, 0);
+}
+
+static void do_signal(struct pt_regs *regs)
+{
+ struct ksignal ksig;
+
+ if (get_signal(&ksig)) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(&ksig, regs);
+ return;
+ }
+
+ /* Are we from a system call? */
+ if (regs->regs[0]) {
+ switch (regs->regs[4]) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ regs->regs[4] = regs->orig_a0;
+ regs->csr_epc -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->regs[4] = regs->orig_a0;
+ regs->regs[11] = current->thread.abi->restart;
+ regs->csr_epc -= 4;
+ break;
+ }
+ regs->regs[0] = 0; /* Don't deal with this again. */
+ }
+
+ /*
+ * If there's no signal to deliver, we just put the saved sigmask
+ * back
+ */
+ restore_saved_sigmask();
+}
+
+/*
+ * notification of userspace execution resumption
+ * - triggered by the TIF_WORK_MASK flags
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
+ __u32 thread_info_flags)
+{
+ local_irq_enable();
+
+ user_exit();
+
+ if (thread_info_flags & _TIF_UPROBE)
+ uprobe_notify_resume(regs);
+
+ /* deal with pending signal delivery */
+ 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);
+ tracehook_notify_resume(regs);
+ rseq_handle_notify_resume(NULL, regs);
+ }
+
+ user_enter();
+}
+
+static int signal_setup(void)
+{
+ /*
+ * The offset from sigcontext to extended context should be the same
+ * regardless of the type of signal, such that userland can always know
+ * where to look if it wishes to find the extended context structures.
+ */
+ BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
+ offsetof(struct sigframe, sf_sc)) !=
+ (offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
+ offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
+
+ if (cpu_has_fpu) {
+ save_fp_context = save_hw_fp_context;
+ restore_fp_context = restore_hw_fp_context;
+ } else {
+ save_fp_context = copy_fp_to_sigcontext;
+ restore_fp_context = copy_fp_from_sigcontext;
+ }
+
+ return 0;
+}
+
+arch_initcall(signal_setup);
--
2.27.0
