arm64: signal: share lp64 signal structures and routines to ilp32

After that, it will be possible to reuse it in ilp32.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>

2 files changed, 111 insertions, 68 deletions

diff --git a/arch/arm64/include/asm/signal_common.h b/arch/arm64/include/asm/signal_common.h
new file mode 100644
index 000000000000..1018811b9ea0
--- /dev/null
+++ b/arch/arm64/include/asm/signal_common.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2017 Cavium Networks.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_SIGNAL_COMMON_H
+#define __ASM_SIGNAL_COMMON_H
+
+#include <linux/uaccess.h>
+#include <asm/fpsimd.h>
+
+#define EXTRA_CONTEXT_SIZE round_up(sizeof(struct extra_context), 16)
+#define TERMINATOR_SIZE round_up(sizeof(struct _aarch64_ctx), 16)
+
+/*
+ * Sanity limit on the approximate maximum size of signal frame we'll
+ * try to generate.  Stack alignment padding and the frame record are
+ * not taken into account.  This limit is not a guarantee and is
+ * NOT ABI.
+ */
+#define SIGFRAME_MAXSZ SZ_64K
+
+#define parse_user_sigcontext(user, sf)					\
+	__parse_user_sigcontext(user, &(sf)->uc.uc_mcontext, sf)
+
+struct user_ctxs {
+	struct fpsimd_context __user *fpsimd;
+	struct sve_context __user *sve;
+};
+
+struct frame_record {
+	u64 fp;
+	u64 lr;
+};
+struct rt_sigframe_user_layout;
+
+int setup_extra_context(char __user *sfp, unsigned long users, char __user *userp);
+int __parse_user_sigcontext(struct user_ctxs *user,
+				   struct sigcontext __user const *sc,
+				   void __user const *sigframe_base);
+
+int preserve_fpsimd_context(struct fpsimd_context __user *ctx);
+int restore_fpsimd_context(struct fpsimd_context __user *ctx);
+
+#ifdef CONFIG_ARM64_SVE
+int preserve_sve_context(struct sve_context __user *ctx);
+int restore_sve_fpsimd_context(struct user_ctxs *user);
+#else /* ! CONFIG_ARM64_SVE */
+
+/* Turn any non-optimised out attempts to use these into a link error: */
+extern int preserve_sve_context(void __user *ctx);
+extern int restore_sve_fpsimd_context(struct user_ctxs *user);
+
+#endif /* ! CONFIG_ARM64_SVE */
+
+#endif /* __ASM_SIGNAL_COMMON_H */
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index e17b8054992a..587c0a532fa7 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -41,6 +41,7 @@
 #include <asm/ptrace.h>
 #include <asm/signal32.h>
 #include <asm/vdso.h>
+#include <asm/signal_common.h>
 
 /*
  * Do a signal return; undo the signal stack. These are aligned to 128-bit.
@@ -50,11 +51,6 @@ struct rt_sigframe {
 	struct ucontext uc;
 };
 
-struct frame_record {
-	u64 fp;
-	u64 lr;
-};
-
 struct rt_sigframe_user_layout {
 	struct rt_sigframe __user *sigframe;
 	struct frame_record __user *next_frame;
@@ -70,8 +66,6 @@ struct rt_sigframe_user_layout {
 };
 
 #define BASE_SIGFRAME_SIZE round_up(sizeof(struct rt_sigframe), 16)
-#define TERMINATOR_SIZE round_up(sizeof(struct _aarch64_ctx), 16)
-#define EXTRA_CONTEXT_SIZE round_up(sizeof(struct extra_context), 16)
 
 static void init_user_layout(struct rt_sigframe_user_layout *user)
 {
@@ -93,14 +87,6 @@ static size_t sigframe_size(struct rt_sigframe_user_layout const *user)
 	return round_up(max(user->size, sizeof(struct rt_sigframe)), 16);
 }
 
-/*
- * Sanity limit on the approximate maximum size of signal frame we'll
- * try to generate.  Stack alignment padding and the frame record are
- * not taken into account.  This limit is not a guarantee and is
- * NOT ABI.
- */
-#define SIGFRAME_MAXSZ SZ_64K
-
 static int __sigframe_alloc(struct rt_sigframe_user_layout *user,
 			    unsigned long *offset, size_t size, bool extend)
 {
@@ -176,7 +162,7 @@ static void __user *apply_user_offset(
 	return base + offset;
 }
 
-static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
+int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
 {
 	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
 	int err;
@@ -193,7 +179,7 @@ static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
 	return err ? -EFAULT : 0;
 }
 
-static int restore_fpsimd_context(struct fpsimd_context __user *ctx)
+int restore_fpsimd_context(struct fpsimd_context __user *ctx)
 {
 	struct fpsimd_state fpsimd;
 	__u32 magic, size;
@@ -222,15 +208,9 @@ static int restore_fpsimd_context(struct fpsimd_context __user *ctx)
 	return err ? -EFAULT : 0;
 }
 
-
-struct user_ctxs {
-	struct fpsimd_context __user *fpsimd;
-	struct sve_context __user *sve;
-};
-
 #ifdef CONFIG_ARM64_SVE
 
-static int preserve_sve_context(struct sve_context __user *ctx)
+int preserve_sve_context(struct sve_context __user *ctx)
 {
 	int err = 0;
 	u16 reserved[ARRAY_SIZE(ctx->__reserved)];
@@ -262,7 +242,7 @@ static int preserve_sve_context(struct sve_context __user *ctx)
 	return err ? -EFAULT : 0;
 }
 
-static int restore_sve_fpsimd_context(struct user_ctxs *user)
+int restore_sve_fpsimd_context(struct user_ctxs *user)
 {
 	int err;
 	unsigned int vq;
@@ -325,15 +305,9 @@ fpsimd_only:
 	return err ? -EFAULT : 0;
 }
 
-#else /* ! CONFIG_ARM64_SVE */
-
-/* Turn any non-optimised out attempts to use these into a link error: */
-extern int preserve_sve_context(void __user *ctx);
-extern int restore_sve_fpsimd_context(struct user_ctxs *user);
-
 #endif /* ! CONFIG_ARM64_SVE */
 
-static int __parse_user_sigcontext(struct user_ctxs *user,
+int __parse_user_sigcontext(struct user_ctxs *user,
 				   struct sigcontext __user const *sc,
 				   void __user const *sigframe_base)
 {
@@ -491,9 +465,6 @@ invalid:
 	return -EINVAL;
 }
 
-#define parse_user_sigcontext(user, sf)					\
-	__parse_user_sigcontext(user, &(sf)->uc.uc_mcontext, sf)
-
 static int restore_sigframe(struct pt_regs *regs,
 			    struct rt_sigframe __user *sf)
 {
@@ -607,6 +578,39 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user)
 	return sigframe_alloc_end(user);
 }
 
+int setup_extra_context(char __user *sfp, unsigned long users, char __user *userp)
+{
+	int err =0;
+	struct extra_context __user *extra;
+	struct _aarch64_ctx __user *end;
+	u64 extra_datap;
+	u32 extra_size;
+
+	extra = (struct extra_context __user *)userp;
+	userp += EXTRA_CONTEXT_SIZE;
+
+	end = (struct _aarch64_ctx __user *)userp;
+	userp += TERMINATOR_SIZE;
+
+	/*
+	 * extra_datap is just written to the signal frame.
+	 * The value gets cast back to a void __user *
+	 * during sigreturn.
+	 */
+	extra_datap = (__force u64)userp;
+	extra_size = sfp + round_up(users, 16) - userp;
+
+	__put_user_error(EXTRA_MAGIC, &extra->head.magic, err);
+	__put_user_error(EXTRA_CONTEXT_SIZE, &extra->head.size, err);
+	__put_user_error(extra_datap, &extra->datap, err);
+	__put_user_error(extra_size, &extra->size, err);
+
+	/* Add the terminator */
+	__put_user_error(0, &end->magic, err);
+	__put_user_error(0, &end->size, err);
+
+	return err;
+}
 
 static int setup_sigframe(struct rt_sigframe_user_layout *user,
 			  struct pt_regs *regs, sigset_t *set)
@@ -652,39 +656,9 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user,
 		err |= preserve_sve_context(sve_ctx);
 	}
 
-	if (err == 0 && user->extra_offset) {
-		char __user *sfp = (char __user *)user->sigframe;
-		char __user *userp =
-			apply_user_offset(user, user->extra_offset);
-
-		struct extra_context __user *extra;
-		struct _aarch64_ctx __user *end;
-		u64 extra_datap;
-		u32 extra_size;
-
-		extra = (struct extra_context __user *)userp;
-		userp += EXTRA_CONTEXT_SIZE;
-
-		end = (struct _aarch64_ctx __user *)userp;
-		userp += TERMINATOR_SIZE;
-
-		/*
-		 * extra_datap is just written to the signal frame.
-		 * The value gets cast back to a void __user *
-		 * during sigreturn.
-		 */
-		extra_datap = (__force u64)userp;
-		extra_size = sfp + round_up(user->size, 16) - userp;
-
-		__put_user_error(EXTRA_MAGIC, &extra->head.magic, err);
-		__put_user_error(EXTRA_CONTEXT_SIZE, &extra->head.size, err);
-		__put_user_error(extra_datap, &extra->datap, err);
-		__put_user_error(extra_size, &extra->size, err);
-
-		/* Add the terminator */
-		__put_user_error(0, &end->magic, err);
-		__put_user_error(0, &end->size, err);
-	}
+	if (err == 0 && user->extra_offset)
+		setup_extra_context((char *) user->sigframe, user->size,
+			(char *) apply_user_offset(user, user->extra_offset));
 
 	/* set the "end" magic */
 	if (err == 0) {