path: root/arch/loongarch/kernel/signal.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Author: Hanlu Li <lihanlu@loongson.cn>
 *         Huacai Chen <chenhuacai@loongson.cn>
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 *
 * Derived from MIPS:
 * Copyright (C) 1991, 1992  Linus Torvalds
 * Copyright (C) 1994 - 2000  Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2014, Imagination Technologies Ltd.
 */
#include <linux/audit.h>
#include <linux/cache.h>
#include <linux/context_tracking.h>
#include <linux/entry-common.h>
#include <linux/irqflags.h>
#include <linux/rseq.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/compiler.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>

#include <asm/asm.h>
#include <asm/cacheflush.h>
#include <asm/cpu-features.h>
#include <asm/fpu.h>
#include <asm/lbt.h>
#include <asm/ucontext.h>
#include <asm/vdso.h>

#ifdef DEBUG_SIG
#  define DEBUGP(fmt, args...) printk("%s: " fmt, __func__, ##args)
#else
#  define DEBUGP(fmt, args...)
#endif

/* Make sure we will not lose FPU ownership */
#define lock_fpu_owner()	({ preempt_disable(); pagefault_disable(); })
#define unlock_fpu_owner()	({ pagefault_enable(); preempt_enable(); })
/* Make sure we will not lose LBT ownership */
#define lock_lbt_owner()	({ preempt_disable(); pagefault_disable(); })
#define unlock_lbt_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);
extern asmlinkage int
_restore_lsx_context(void __user *fpregs, void __user *fcc, void __user *fcsr);
extern asmlinkage int
_save_lasx_context(void __user *fpregs, void __user *fcc, void __user *fcsr);
extern asmlinkage int
_restore_lasx_context(void __user *fpregs, void __user *fcc, void __user *fcsr);

#ifdef CONFIG_CPU_HAS_LBT
extern asmlinkage int _save_lbt_context(void __user *regs, void __user *eflags);
extern asmlinkage int _restore_lbt_context(void __user *regs, void __user *eflags);
extern asmlinkage int _save_ftop_context(void __user *ftop);
extern asmlinkage int _restore_ftop_context(void __user *ftop);
#endif

struct rt_sigframe {
	struct siginfo rs_info;
	struct ucontext rs_uctx;
};

struct _ctx_layout {
	struct sctx_info *addr;
	unsigned int size;
};

struct extctx_layout {
	unsigned long size;
	unsigned int flags;
	struct _ctx_layout fpu;
	struct _ctx_layout lsx;
	struct _ctx_layout lasx;
	struct _ctx_layout lbt;
	struct _ctx_layout end;
};

static void __user *get_ctx_through_ctxinfo(struct sctx_info *info)
{
	return (void __user *)((char *)info + sizeof(struct sctx_info));
}

/*
 * 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_fpu_to_sigcontext(struct fpu_context __user *ctx)
{
	int i;
	int err = 0;
	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
	uint64_t __user *fcc	= &ctx->fcc;
	uint32_t __user *fcsr	= &ctx->fcsr;

	for (i = 0; i < NUM_FPU_REGS; i++) {
		err |=
		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
			       &regs[i]);
	}
	err |= __put_user(current->thread.fpu.fcc, fcc);
	err |= __put_user(current->thread.fpu.fcsr, fcsr);

	return err;
}

static int copy_fpu_from_sigcontext(struct fpu_context __user *ctx)
{
	int i;
	int err = 0;
	u64 fpr_val;
	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
	uint64_t __user *fcc	= &ctx->fcc;
	uint32_t __user *fcsr	= &ctx->fcsr;

	for (i = 0; i < NUM_FPU_REGS; i++) {
		err |= __get_user(fpr_val, &regs[i]);
		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
	}
	err |= __get_user(current->thread.fpu.fcc, fcc);
	err |= __get_user(current->thread.fpu.fcsr, fcsr);

	return err;
}

static int copy_lsx_to_sigcontext(struct lsx_context __user *ctx)
{
	int i;
	int err = 0;
	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
	uint64_t __user *fcc	= &ctx->fcc;
	uint32_t __user *fcsr	= &ctx<