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-rw-r--r--arch/loongarch/kernel/signal.c1075
1 files changed, 1075 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/signal.c b/arch/loongarch/kernel/signal.c
new file mode 100644
index 0000000000..4a3686d133
--- /dev/null
+++ b/arch/loongarch/kernel/signal.c
@@ -0,0 +1,1075 @@
+// 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/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->fcsr;
+
+ for (i = 0; i < NUM_FPU_REGS; i++) {
+ err |= __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
+ &regs[2*i]);
+ err |= __put_user(get_fpr64(&current->thread.fpu.fpr[i], 1),
+ &regs[2*i+1]);
+ }
+ err |= __put_user(current->thread.fpu.fcc, fcc);
+ err |= __put_user(current->thread.fpu.fcsr, fcsr);
+
+ return err;
+}
+
+static int copy_lsx_from_sigcontext(struct lsx_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[2*i]);
+ set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+ err |= __get_user(fpr_val, &regs[2*i+1]);
+ set_fpr64(&current->thread.fpu.fpr[i], 1, fpr_val);
+ }
+ err |= __get_user(current->thread.fpu.fcc, fcc);
+ err |= __get_user(current->thread.fpu.fcsr, fcsr);
+
+ return err;
+}
+
+static int copy_lasx_to_sigcontext(struct lasx_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[4*i]);
+ err |= __put_user(get_fpr64(&current->thread.fpu.fpr[i], 1),
+ &regs[4*i+1]);
+ err |= __put_user(get_fpr64(&current->thread.fpu.fpr[i], 2),
+ &regs[4*i+2]);
+ err |= __put_user(get_fpr64(&current->thread.fpu.fpr[i], 3),
+ &regs[4*i+3]);
+ }
+ err |= __put_user(current->thread.fpu.fcc, fcc);
+ err |= __put_user(current->thread.fpu.fcsr, fcsr);
+
+ return err;
+}
+
+static int copy_lasx_from_sigcontext(struct lasx_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[4*i]);
+ set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+ err |= __get_user(fpr_val, &regs[4*i+1]);
+ set_fpr64(&current->thread.fpu.fpr[i], 1, fpr_val);
+ err |= __get_user(fpr_val, &regs[4*i+2]);
+ set_fpr64(&current->thread.fpu.fpr[i], 2, fpr_val);
+ err |= __get_user(fpr_val, &regs[4*i+3]);
+ set_fpr64(&current->thread.fpu.fpr[i], 3, fpr_val);
+ }
+ err |= __get_user(current->thread.fpu.fcc, fcc);
+ err |= __get_user(current->thread.fpu.fcsr, fcsr);
+
+ return err;
+}
+
+#ifdef CONFIG_CPU_HAS_LBT
+static int copy_lbt_to_sigcontext(struct lbt_context __user *ctx)
+{
+ int err = 0;
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&ctx->eflags;
+
+ err |= __put_user(current->thread.lbt.scr0, &regs[0]);
+ err |= __put_user(current->thread.lbt.scr1, &regs[1]);
+ err |= __put_user(current->thread.lbt.scr2, &regs[2]);
+ err |= __put_user(current->thread.lbt.scr3, &regs[3]);
+ err |= __put_user(current->thread.lbt.eflags, eflags);
+
+ return err;
+}
+
+static int copy_lbt_from_sigcontext(struct lbt_context __user *ctx)
+{
+ int err = 0;
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&ctx->eflags;
+
+ err |= __get_user(current->thread.lbt.scr0, &regs[0]);
+ err |= __get_user(current->thread.lbt.scr1, &regs[1]);
+ err |= __get_user(current->thread.lbt.scr2, &regs[2]);
+ err |= __get_user(current->thread.lbt.scr3, &regs[3]);
+ err |= __get_user(current->thread.lbt.eflags, eflags);
+
+ return err;
+}
+
+static int copy_ftop_to_sigcontext(struct lbt_context __user *ctx)
+{
+ uint32_t __user *ftop = &ctx->ftop;
+
+ return __put_user(current->thread.fpu.ftop, ftop);
+}
+
+static int copy_ftop_from_sigcontext(struct lbt_context __user *ctx)
+{
+ uint32_t __user *ftop = &ctx->ftop;
+
+ return __get_user(current->thread.fpu.ftop, ftop);
+}
+#endif
+
+/*
+ * Wrappers for the assembly _{save,restore}_fp_context functions.
+ */
+static int save_hw_fpu_context(struct fpu_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _save_fp_context(regs, fcc, fcsr);
+}
+
+static int restore_hw_fpu_context(struct fpu_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _restore_fp_context(regs, fcc, fcsr);
+}
+
+static int save_hw_lsx_context(struct lsx_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _save_lsx_context(regs, fcc, fcsr);
+}
+
+static int restore_hw_lsx_context(struct lsx_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _restore_lsx_context(regs, fcc, fcsr);
+}
+
+static int save_hw_lasx_context(struct lasx_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _save_lasx_context(regs, fcc, fcsr);
+}
+
+static int restore_hw_lasx_context(struct lasx_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint64_t __user *fcc = &ctx->fcc;
+ uint32_t __user *fcsr = &ctx->fcsr;
+
+ return _restore_lasx_context(regs, fcc, fcsr);
+}
+
+/*
+ * Wrappers for the assembly _{save,restore}_lbt_context functions.
+ */
+#ifdef CONFIG_CPU_HAS_LBT
+static int save_hw_lbt_context(struct lbt_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&ctx->eflags;
+
+ return _save_lbt_context(regs, eflags);
+}
+
+static int restore_hw_lbt_context(struct lbt_context __user *ctx)
+{
+ uint64_t __user *regs = (uint64_t *)&ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&ctx->eflags;
+
+ return _restore_lbt_context(regs, eflags);
+}
+
+static int save_hw_ftop_context(struct lbt_context __user *ctx)
+{
+ uint32_t __user *ftop = &ctx->ftop;
+
+ return _save_ftop_context(ftop);
+}
+
+static int restore_hw_ftop_context(struct lbt_context __user *ctx)
+{
+ uint32_t __user *ftop = &ctx->ftop;
+
+ return _restore_ftop_context(ftop);
+}
+#endif
+
+static int fcsr_pending(unsigned int __user *fcsr)
+{
+ int err, sig = 0;
+ unsigned int csr, enabled;
+
+ err = __get_user(csr, fcsr);
+ 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, fcsr);
+ sig = SIGFPE;
+ }
+ return err ?: sig;
+}
+
+/*
+ * Helper routines
+ */
+static int protected_save_fpu_context(struct extctx_layout *extctx)
+{
+ int err = 0;
+ struct sctx_info __user *info = extctx->fpu.addr;
+ struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&fpu_ctx->regs;
+ uint64_t __user *fcc = &fpu_ctx->fcc;
+ uint32_t __user *fcsr = &fpu_ctx->fcsr;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner())
+ err = save_hw_fpu_context(fpu_ctx);
+ else
+ err = copy_fpu_to_sigcontext(fpu_ctx);
+ unlock_fpu_owner();
+
+ err |= __put_user(FPU_CTX_MAGIC, &info->magic);
+ err |= __put_user(extctx->fpu.size, &info->size);
+
+ if (likely(!err))
+ break;
+ /* Touch the FPU context and try again */
+ err = __put_user(0, &regs[0]) |
+ __put_user(0, &regs[31]) |
+ __put_user(0, fcc) |
+ __put_user(0, fcsr);
+ if (err)
+ return err; /* really bad sigcontext */
+ }
+
+ return err;
+}
+
+static int protected_restore_fpu_context(struct extctx_layout *extctx)
+{
+ int err = 0, sig = 0, tmp __maybe_unused;
+ struct sctx_info __user *info = extctx->fpu.addr;
+ struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&fpu_ctx->regs;
+ uint64_t __user *fcc = &fpu_ctx->fcc;
+ uint32_t __user *fcsr = &fpu_ctx->fcsr;
+
+ err = sig = fcsr_pending(fcsr);
+ if (err < 0)
+ return err;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner())
+ err = restore_hw_fpu_context(fpu_ctx);
+ else
+ err = copy_fpu_from_sigcontext(fpu_ctx);
+ unlock_fpu_owner();
+
+ if (likely(!err))
+ break;
+ /* Touch the FPU context and try again */
+ err = __get_user(tmp, &regs[0]) |
+ __get_user(tmp, &regs[31]) |
+ __get_user(tmp, fcc) |
+ __get_user(tmp, fcsr);
+ if (err)
+ break; /* really bad sigcontext */
+ }
+
+ return err ?: sig;
+}
+
+static int protected_save_lsx_context(struct extctx_layout *extctx)
+{
+ int err = 0;
+ struct sctx_info __user *info = extctx->lsx.addr;
+ struct lsx_context __user *lsx_ctx = (struct lsx_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lsx_ctx->regs;
+ uint64_t __user *fcc = &lsx_ctx->fcc;
+ uint32_t __user *fcsr = &lsx_ctx->fcsr;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_lsx_enabled())
+ err = save_hw_lsx_context(lsx_ctx);
+ else {
+ if (is_fpu_owner())
+ save_fp(current);
+ err = copy_lsx_to_sigcontext(lsx_ctx);
+ }
+ unlock_fpu_owner();
+
+ err |= __put_user(LSX_CTX_MAGIC, &info->magic);
+ err |= __put_user(extctx->lsx.size, &info->size);
+
+ if (likely(!err))
+ break;
+ /* Touch the LSX context and try again */
+ err = __put_user(0, &regs[0]) |
+ __put_user(0, &regs[32*2-1]) |
+ __put_user(0, fcc) |
+ __put_user(0, fcsr);
+ if (err)
+ return err; /* really bad sigcontext */
+ }
+
+ return err;
+}
+
+static int protected_restore_lsx_context(struct extctx_layout *extctx)
+{
+ int err = 0, sig = 0, tmp __maybe_unused;
+ struct sctx_info __user *info = extctx->lsx.addr;
+ struct lsx_context __user *lsx_ctx = (struct lsx_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lsx_ctx->regs;
+ uint64_t __user *fcc = &lsx_ctx->fcc;
+ uint32_t __user *fcsr = &lsx_ctx->fcsr;
+
+ err = sig = fcsr_pending(fcsr);
+ if (err < 0)
+ return err;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_lsx_enabled())
+ err = restore_hw_lsx_context(lsx_ctx);
+ else {
+ err = copy_lsx_from_sigcontext(lsx_ctx);
+ if (is_fpu_owner())
+ restore_fp(current);
+ }
+ unlock_fpu_owner();
+
+ if (likely(!err))
+ break;
+ /* Touch the LSX context and try again */
+ err = __get_user(tmp, &regs[0]) |
+ __get_user(tmp, &regs[32*2-1]) |
+ __get_user(tmp, fcc) |
+ __get_user(tmp, fcsr);
+ if (err)
+ break; /* really bad sigcontext */
+ }
+
+ return err ?: sig;
+}
+
+static int protected_save_lasx_context(struct extctx_layout *extctx)
+{
+ int err = 0;
+ struct sctx_info __user *info = extctx->lasx.addr;
+ struct lasx_context __user *lasx_ctx =
+ (struct lasx_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lasx_ctx->regs;
+ uint64_t __user *fcc = &lasx_ctx->fcc;
+ uint32_t __user *fcsr = &lasx_ctx->fcsr;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_lasx_enabled())
+ err = save_hw_lasx_context(lasx_ctx);
+ else {
+ if (is_lsx_enabled())
+ save_lsx(current);
+ else if (is_fpu_owner())
+ save_fp(current);
+ err = copy_lasx_to_sigcontext(lasx_ctx);
+ }
+ unlock_fpu_owner();
+
+ err |= __put_user(LASX_CTX_MAGIC, &info->magic);
+ err |= __put_user(extctx->lasx.size, &info->size);
+
+ if (likely(!err))
+ break;
+ /* Touch the LASX context and try again */
+ err = __put_user(0, &regs[0]) |
+ __put_user(0, &regs[32*4-1]) |
+ __put_user(0, fcc) |
+ __put_user(0, fcsr);
+ if (err)
+ return err; /* really bad sigcontext */
+ }
+
+ return err;
+}
+
+static int protected_restore_lasx_context(struct extctx_layout *extctx)
+{
+ int err = 0, sig = 0, tmp __maybe_unused;
+ struct sctx_info __user *info = extctx->lasx.addr;
+ struct lasx_context __user *lasx_ctx =
+ (struct lasx_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lasx_ctx->regs;
+ uint64_t __user *fcc = &lasx_ctx->fcc;
+ uint32_t __user *fcsr = &lasx_ctx->fcsr;
+
+ err = sig = fcsr_pending(fcsr);
+ if (err < 0)
+ return err;
+
+ while (1) {
+ lock_fpu_owner();
+ if (is_lasx_enabled())
+ err = restore_hw_lasx_context(lasx_ctx);
+ else {
+ err = copy_lasx_from_sigcontext(lasx_ctx);
+ if (is_lsx_enabled())
+ restore_lsx(current);
+ else if (is_fpu_owner())
+ restore_fp(current);
+ }
+ unlock_fpu_owner();
+
+ if (likely(!err))
+ break;
+ /* Touch the LASX context and try again */
+ err = __get_user(tmp, &regs[0]) |
+ __get_user(tmp, &regs[32*4-1]) |
+ __get_user(tmp, fcc) |
+ __get_user(tmp, fcsr);
+ if (err)
+ break; /* really bad sigcontext */
+ }
+
+ return err ?: sig;
+}
+
+#ifdef CONFIG_CPU_HAS_LBT
+static int protected_save_lbt_context(struct extctx_layout *extctx)
+{
+ int err = 0;
+ struct sctx_info __user *info = extctx->lbt.addr;
+ struct lbt_context __user *lbt_ctx =
+ (struct lbt_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lbt_ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&lbt_ctx->eflags;
+
+ while (1) {
+ lock_lbt_owner();
+ if (is_lbt_owner())
+ err |= save_hw_lbt_context(lbt_ctx);
+ else
+ err |= copy_lbt_to_sigcontext(lbt_ctx);
+ if (is_fpu_owner())
+ err |= save_hw_ftop_context(lbt_ctx);
+ else
+ err |= copy_ftop_to_sigcontext(lbt_ctx);
+ unlock_lbt_owner();
+
+ err |= __put_user(LBT_CTX_MAGIC, &info->magic);
+ err |= __put_user(extctx->lbt.size, &info->size);
+
+ if (likely(!err))
+ break;
+ /* Touch the LBT context and try again */
+ err = __put_user(0, &regs[0]) | __put_user(0, eflags);
+
+ if (err)
+ return err;
+ }
+
+ return err;
+}
+
+static int protected_restore_lbt_context(struct extctx_layout *extctx)
+{
+ int err = 0, tmp __maybe_unused;
+ struct sctx_info __user *info = extctx->lbt.addr;
+ struct lbt_context __user *lbt_ctx =
+ (struct lbt_context *)get_ctx_through_ctxinfo(info);
+ uint64_t __user *regs = (uint64_t *)&lbt_ctx->regs;
+ uint32_t __user *eflags = (uint32_t *)&lbt_ctx->eflags;
+
+ while (1) {
+ lock_lbt_owner();
+ if (is_lbt_owner())
+ err |= restore_hw_lbt_context(lbt_ctx);
+ else
+ err |= copy_lbt_from_sigcontext(lbt_ctx);
+ if (is_fpu_owner())
+ err |= restore_hw_ftop_context(lbt_ctx);
+ else
+ err |= copy_ftop_from_sigcontext(lbt_ctx);
+ unlock_lbt_owner();
+
+ if (likely(!err))
+ break;
+ /* Touch the LBT context and try again */
+ err = __get_user(tmp, &regs[0]) | __get_user(tmp, eflags);
+
+ if (err)
+ return err;
+ }
+
+ return err;
+}
+#endif
+
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
+ struct extctx_layout *extctx)
+{
+ int i, err = 0;
+ struct sctx_info __user *info;
+
+ err |= __put_user(regs->csr_era, &sc->sc_pc);
+ err |= __put_user(extctx->flags, &sc->sc_flags);
+
+ err |= __put_user(0, &sc->sc_regs[0]);
+ for (i = 1; i < 32; i++)
+ err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
+
+ if (extctx->lasx.addr)
+ err |= protected_save_lasx_context(extctx);
+ else if (extctx->lsx.addr)
+ err |= protected_save_lsx_context(extctx);
+ else if (extctx->fpu.addr)
+ err |= protected_save_fpu_context(extctx);
+
+#ifdef CONFIG_CPU_HAS_LBT
+ if (extctx->lbt.addr)
+ err |= protected_save_lbt_context(extctx);
+#endif
+
+ /* Set the "end" magic */
+ info = (struct sctx_info *)extctx->end.addr;
+ err |= __put_user(0, &info->magic);
+ err |= __put_user(0, &info->size);
+
+ return err;
+}
+
+static int parse_extcontext(struct sigcontext __user *sc, struct extctx_layout *extctx)
+{
+ int err = 0;
+ unsigned int magic, size;
+ struct sctx_info __user *info = (struct sctx_info __user *)&sc->sc_extcontext;
+
+ while(1) {
+ err |= __get_user(magic, &info->magic);
+ err |= __get_user(size, &info->size);
+ if (err)
+ return err;
+
+ switch (magic) {
+ case 0: /* END */
+ goto done;
+
+ case FPU_CTX_MAGIC:
+ if (size < (sizeof(struct sctx_info) +
+ sizeof(struct fpu_context)))
+ goto invalid;
+ extctx->fpu.addr = info;
+ break;
+
+ case LSX_CTX_MAGIC:
+ if (size < (sizeof(struct sctx_info) +
+ sizeof(struct lsx_context)))
+ goto invalid;
+ extctx->lsx.addr = info;
+ break;
+
+ case LASX_CTX_MAGIC:
+ if (size < (sizeof(struct sctx_info) +
+ sizeof(struct lasx_context)))
+ goto invalid;
+ extctx->lasx.addr = info;
+ break;
+
+ case LBT_CTX_MAGIC:
+ if (size < (sizeof(struct sctx_info) +
+ sizeof(struct lbt_context)))
+ goto invalid;
+ extctx->lbt.addr = info;
+ break;
+
+ default:
+ goto invalid;
+ }
+
+ info = (struct sctx_info *)((char *)info + size);
+ }
+
+done:
+ return 0;
+
+invalid:
+ return -EINVAL;
+}
+
+static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int i, err = 0;
+ struct extctx_layout extctx;
+
+ memset(&extctx, 0, sizeof(struct extctx_layout));
+
+ err = __get_user(extctx.flags, &sc->sc_flags);
+ if (err)
+ goto bad;
+
+ err = parse_extcontext(sc, &extctx);
+ if (err)
+ goto bad;
+
+ conditional_used_math(extctx.flags & SC_USED_FP);
+
+ /*
+ * The signal handler may have used FPU; give it up if the program
+ * doesn't want it following sigreturn.
+ */
+ if (!(extctx.flags & SC_USED_FP))
+ lose_fpu(0);
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ err |= __get_user(regs->csr_era, &sc->sc_pc);
+ for (i = 1; i < 32; i++)
+ err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
+
+ if (extctx.lasx.addr)
+ err |= protected_restore_lasx_context(&extctx);
+ else if (extctx.lsx.addr)
+ err |= protected_restore_lsx_context(&extctx);
+ else if (extctx.fpu.addr)
+ err |= protected_restore_fpu_context(&extctx);
+
+#ifdef CONFIG_CPU_HAS_LBT
+ if (extctx.lbt.addr)
+ err |= protected_restore_lbt_context(&extctx);
+#endif
+
+bad:
+ return err;
+}
+
+static unsigned int handle_flags(void)
+{
+ unsigned int flags = 0;
+
+ flags = used_math() ? SC_USED_FP : 0;
+
+ switch (current->thread.error_code) {
+ case 1:
+ flags |= SC_ADDRERR_RD;
+ break;
+ case 2:
+ flags |= SC_ADDRERR_WR;
+ break;
+ }
+
+ return flags;
+}
+
+static unsigned long extframe_alloc(struct extctx_layout *extctx,
+ struct _ctx_layout *layout,
+ size_t size, unsigned int align, unsigned long base)
+{
+ unsigned long new_base = base - size;
+
+ new_base = round_down(new_base, (align < 16 ? 16 : align));
+ new_base -= sizeof(struct sctx_info);
+
+ layout->addr = (void *)new_base;
+ layout->size = (unsigned int)(base - new_base);
+ extctx->size += layout->size;
+
+ return new_base;
+}
+
+static unsigned long setup_extcontext(struct extctx_layout *extctx, unsigned long sp)
+{
+ unsigned long new_sp = sp;
+
+ memset(extctx, 0, sizeof(struct extctx_layout));
+
+ extctx->flags = handle_flags();
+
+ /* Grow down, alloc "end" context info first. */
+ new_sp -= sizeof(struct sctx_info);
+ extctx->end.addr = (void *)new_sp;
+ extctx->end.size = (unsigned int)sizeof(struct sctx_info);
+ extctx->size += extctx->end.size;
+
+ if (extctx->flags & SC_USED_FP) {
+ if (cpu_has_lasx && thread_lasx_context_live())
+ new_sp = extframe_alloc(extctx, &extctx->lasx,
+ sizeof(struct lasx_context), LASX_CTX_ALIGN, new_sp);
+ else if (cpu_has_lsx && thread_lsx_context_live())
+ new_sp = extframe_alloc(extctx, &extctx->lsx,
+ sizeof(struct lsx_context), LSX_CTX_ALIGN, new_sp);
+ else if (cpu_has_fpu)
+ new_sp = extframe_alloc(extctx, &extctx->fpu,
+ sizeof(struct fpu_context), FPU_CTX_ALIGN, new_sp);
+ }
+
+#ifdef CONFIG_CPU_HAS_LBT
+ if (cpu_has_lbt && thread_lbt_context_live()) {
+ new_sp = extframe_alloc(extctx, &extctx->lbt,
+ sizeof(struct lbt_context), LBT_CTX_ALIGN, new_sp);
+ }
+#endif
+
+ return new_sp;
+}
+
+static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+ struct extctx_layout *extctx)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->regs[3];
+
+ /*
+ * 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 - sizeof(struct rt_sigframe))))
+ return (void __user __force *)(-1UL);
+
+ sp = sigsp(sp, ksig);
+ sp = round_down(sp, 16);
+ sp = setup_extcontext(extctx, sp);
+ sp -= sizeof(struct rt_sigframe);
+
+ if (!IS_ALIGNED(sp, 16))
+ BUG();
+
+ return (void __user *)sp;
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+ int sig;
+ sigset_t set;
+ struct pt_regs *regs;
+ struct rt_sigframe __user *frame;
+
+ 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_uctx.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ sig = restore_sigcontext(regs, &frame->rs_uctx.uc_mcontext);
+ if (sig < 0)
+ goto badframe;
+ else if (sig)
+ force_sig(sig);
+
+ regs->regs[0] = 0; /* No syscall restarting */
+ if (restore_altstack(&frame->rs_uctx.uc_stack))
+ goto badframe;
+
+ return regs->regs[4];
+
+badframe:
+ force_sig(SIGSEGV);
+ return 0;
+}
+
+static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
+ struct pt_regs *regs, sigset_t *set)
+{
+ int err = 0;
+ struct extctx_layout extctx;
+ struct rt_sigframe __user *frame;
+
+ frame = get_sigframe(ksig, regs, &extctx);
+ if (!access_ok(frame, sizeof(*frame) + extctx.size))
+ return -EFAULT;
+
+ /* Create siginfo. */
+ err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->rs_uctx.uc_flags);
+ err |= __put_user(NULL, &frame->rs_uctx.uc_link);
+ err |= __save_altstack(&frame->rs_uctx.uc_stack, regs->regs[3]);
+ err |= setup_sigcontext(regs, &frame->rs_uctx.uc_mcontext, &extctx);
+ err |= __copy_to_user(&frame->rs_uctx.uc_sigmask, set, sizeof(*set));
+
+ if (err)
+ return -EFAULT;
+
+ /*
+ * Arguments to signal handler:
+ *
+ * a0 = signal number
+ * a1 = pointer to siginfo
+ * a2 = pointer to ucontext
+ *
+ * c0_era point to the signal handler, $r3 (sp) 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_uctx;
+ regs->regs[3] = (unsigned long) frame;
+ regs->regs[1] = (unsigned long) sig_return;
+ regs->csr_era = (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_era, regs->regs[1]);
+
+ return 0;
+}
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ int ret;
+ sigset_t *oldset = sigmask_to_save();
+ 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_era -= 4;
+ }
+
+ regs->regs[0] = 0; /* Don't deal with this again. */
+ }
+
+ rseq_signal_deliver(ksig, regs);
+
+ ret = setup_rt_frame(vdso + current->thread.vdso->offset_sigreturn, ksig, regs, oldset);
+
+ signal_setup_done(ret, ksig, 0);
+}
+
+void arch_do_signal_or_restart(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_era -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->regs[4] = regs->orig_a0;
+ regs->regs[11] = __NR_restart_syscall;
+ regs->csr_era -= 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();
+}