[PATCH OLK-6.6 v2 16/31] arm64: signal: share lp64 signal structures and routines to ilp32

29 Nov 2023

From: Yury Norov ynorov@caviumnetworks.com
maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8JVJ3
CVE: NA
Reference: https://github.com/norov/linux/commits/ilp32-5.2
--------------------------------
Following patches of the series introduce ILP32-specific structures and
handlers for signal subsystem. In this patch, functions and structures
that common for LP64 and ILP32 are moved to
arch/arm64/include/asm/signal_common.h to let ILP32 code reuse them. Some
functions work with struct rt_sigframe which differs for ILP32. Therefore,
to let ILP32 generate correct code, body of that functions are moved to
arch/arm64/include/asm/signal_common.h. Others just declared in new header.
Signed-off-by: Yury Norov ynorov@caviumnetworks.com
Signed-off-by: Yury Norov ynorov@marvell.com
Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com
Acked-by: Xie XiuQi xiexiuqi@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com
Signed-off-by: Chen Jiahao chenjiahao16@huawei.com
Signed-off-by: Jinjie Ruan ruanjinjie@huawei.com
---
 arch/arm64/include/asm/signal_common.h | 391 +++++++++++++++++++++++++
 arch/arm64/kernel/signal.c             | 379 ++++--------------------
 2 files changed, 448 insertions(+), 322 deletions(-)
 create mode 100644 arch/arm64/include/asm/signal_common.h

diff --git a/arch/arm64/include/asm/signal_common.h b/arch/arm64/include/asm/signal_common.h
new file mode 100644
index 000000000000..460efa29d5a6
--- /dev/null
+++ b/arch/arm64/include/asm/signal_common.h
@@ -0,0 +1,391 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2018 Cavium Networks.
+ */
+
+#ifndef __ASM_SIGNAL_COMMON_H
+#define __ASM_SIGNAL_COMMON_H
+
+#include <linux/uaccess.h>
+#include <asm/fpsimd.h>
+#include <asm/traps.h>
+
+#define EXTRA_CONTEXT_SIZE round_up(sizeof(struct extra_context), 16)
+#define TERMINATOR_SIZE round_up(sizeof(struct _aarch64_ctx), 16)
+#define SIGCONTEXT_RESERVED_SIZE sizeof(((struct sigcontext *)0)->__reserved)
+#define RT_SIGFRAME_RESERVED_OFFSET \
+		offsetof(struct rt_sigframe, uc.uc_mcontext.__reserved)
+
+/*
+ * 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
+
+struct rt_sigframe_user_layout {
+	struct rt_sigframe __user *sigframe;
+	struct frame_record __user *next_frame;
+
+	unsigned long size;	/* size of allocated sigframe data */
+	unsigned long limit;	/* largest allowed size */
+
+	unsigned long fpsimd_offset;
+	unsigned long esr_offset;
+	unsigned long sve_offset;
+	unsigned long tpidr2_offset;
+	unsigned long za_offset;
+	unsigned long zt_offset;
+	unsigned long extra_offset;
+	unsigned long end_offset;
+};
+
+struct user_ctxs {
+	struct fpsimd_context __user *fpsimd;
+	u32 fpsimd_size;
+	struct sve_context __user *sve;
+	u32 sve_size;
+	struct tpidr2_context __user *tpidr2;
+	u32 tpidr2_size;
+	struct za_context __user *za;
+	u32 za_size;
+	struct zt_context __user *zt;
+	u32 zt_size;
+};
+
+struct frame_record {
+	u64 fp;
+	u64 lr;
+};
+
+void __user *apply_user_offset(struct rt_sigframe_user_layout const *user,
+			       unsigned long offset);
+
+int setup_sigframe_layout(struct rt_sigframe_user_layout *user, bool add_all);
+int setup_extra_context(char __user *sfp, unsigned long sf_size,
+			char __user *exprap);
+int __parse_user_sigcontext(struct user_ctxs *user,
+				   struct sigcontext __user const *sc,
+				   void __user const *sigframe_base);
+#define parse_user_sigcontext(user, sf)					\
+	__parse_user_sigcontext(user, &(sf)->uc.uc_mcontext, sf)
+
+int preserve_fpsimd_context(struct fpsimd_context __user *ctx);
+int restore_fpsimd_context(struct user_ctxs *user);
+
+#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 */
+
+
+#ifdef CONFIG_ARM64_SME
+int preserve_tpidr2_context(struct tpidr2_context __user *ctx);
+int restore_tpidr2_context(struct user_ctxs *user);
+int preserve_za_context(struct za_context __user *ctx);
+int restore_za_context(struct user_ctxs *user);
+int preserve_zt_context(struct zt_context __user *ctx);
+int restore_zt_context(struct user_ctxs *user);
+#else /* ! CONFIG_ARM64_SME */
+
+/* Turn any non-optimised out attempts to use these into a link error: */
+extern int preserve_tpidr2_context(void __user *ctx);
+extern int restore_tpidr2_context(struct user_ctxs *user);
+extern int preserve_za_context(void __user *ctx);
+extern int restore_za_context(struct user_ctxs *user);
+extern int preserve_zt_context(void __user *ctx);
+extern int restore_zt_context(struct user_ctxs *user);
+
+#endif /* ! CONFIG_ARM64_SME */
+
+int sigframe_alloc(struct rt_sigframe_user_layout *user,
+		   unsigned long *offset, size_t size);
+int sigframe_alloc_end(struct rt_sigframe_user_layout *user);
+
+void __setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+		    struct rt_sigframe_user_layout *user, int usig);
+
+static void init_user_layout(struct rt_sigframe_user_layout *user)
+{
+	const size_t reserved_size =
+		sizeof(user->sigframe->uc.uc_mcontext.__reserved);
+
+	memset(user, 0, sizeof(*user));
+	user->size = offsetof(struct rt_sigframe, uc.uc_mcontext.__reserved);
+
+	user->limit = user->size + reserved_size;
+
+	user->limit -= TERMINATOR_SIZE;
+	user->limit -= EXTRA_CONTEXT_SIZE;
+	/* Reserve space for extension and terminator ^ */
+}
+
+static size_t sigframe_size(struct rt_sigframe_user_layout const *user)
+{
+	return round_up(max(user->size, sizeof(struct rt_sigframe)), 16);
+}
+
+static int get_sigframe(struct rt_sigframe_user_layout *user,
+			 struct ksignal *ksig, struct pt_regs *regs)
+{
+	unsigned long sp, sp_top;
+	int err;
+
+	init_user_layout(user);
+	err = setup_sigframe_layout(user, false);
+	if (err)
+		return err;
+
+	sp = sp_top = sigsp(regs->sp, ksig);
+
+	sp = round_down(sp - sizeof(struct frame_record), 16);
+	user->next_frame = (struct frame_record __user *)sp;
+
+	sp = round_down(sp, 16) - sigframe_size(user);
+	user->sigframe = (void __user *)sp;
+
+	/*
+	 * Check that we can actually write to the signal frame.
+	 */
+	if (!access_ok(VERIFY_WRITE, user->sigframe, sp_top - sp))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int restore_sigframe(struct pt_regs *regs,
+			    struct rt_sigframe __user *sf)
+{
+	sigset_t set;
+	int i, err;
+	struct user_ctxs user;
+
+	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
+	if (err == 0)
+		set_current_blocked(&set);
+
+	for (i = 0; i < 31; i++)
+		__get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
+				 err);
+	__get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
+	__get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
+	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
+
+	/*
+	 * Avoid sys_rt_sigreturn() restarting.
+	 */
+	forget_syscall(regs);
+
+	err |= !valid_user_regs(&regs->user_regs, current);
+	if (err == 0)
+		err = parse_user_sigcontext(&user, sf);
+
+	if (err == 0 && system_supports_fpsimd()) {
+		if (!user.fpsimd)
+			return -EINVAL;
+
+		if (user.sve)
+			err = restore_sve_fpsimd_context(&user);
+		else
+			err = restore_fpsimd_context(&user);
+	}
+
+	if (err == 0 && system_supports_tpidr2() && user.tpidr2)
+		err = restore_tpidr2_context(&user);
+
+	if (err == 0 && system_supports_sme() && user.za)
+		err = restore_za_context(&user);
+
+	if (err == 0 && system_supports_sme2() && user.zt)
+		err = restore_zt_context(&user);
+
+	return err;
+}
+
+static int setup_sigframe(struct rt_sigframe_user_layout *user,
+			  struct pt_regs *regs, sigset_t *set)
+{
+	int i, err = 0;
+	struct rt_sigframe __user *sf = user->sigframe;
+
+	/* set up the stack frame for unwinding */
+	__put_user_error(regs->regs[29], &user->next_frame->fp, err);
+	__put_user_error(regs->regs[30], &user->next_frame->lr, err);
+
+	for (i = 0; i < 31; i++)
+		__put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
+				 err);
+	__put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
+	__put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
+	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
+
+	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
+
+	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
+
+	if (err == 0 && system_supports_fpsimd()) {
+		struct fpsimd_context __user *fpsimd_ctx =
+			apply_user_offset(user, user->fpsimd_offset);
+		err |= preserve_fpsimd_context(fpsimd_ctx);
+	}
+
+	/* fault information, if valid */
+	if (err == 0 && user->esr_offset) {
+		struct esr_context __user *esr_ctx =
+			apply_user_offset(user, user->esr_offset);
+
+		__put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err);
+		__put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err);
+		__put_user_error(current->thread.fault_code, &esr_ctx->esr, err);
+	}
+
+	/* Scalable Vector Extension state (including streaming), if present */
+	if ((system_supports_sve() || system_supports_sme()) &&
+	    err == 0 && user->sve_offset) {
+		struct sve_context __user *sve_ctx =
+			apply_user_offset(user, user->sve_offset);
+		err |= preserve_sve_context(sve_ctx);
+	}
+
+	/* TPIDR2 if supported */
+	if (system_supports_tpidr2() && err == 0) {
+		struct tpidr2_context __user *tpidr2_ctx =
+			apply_user_offset(user, user->tpidr2_offset);
+		err |= preserve_tpidr2_context(tpidr2_ctx);
+	}
+
+	/* ZA state if present */
+	if (system_supports_sme() && err == 0 && user->za_offset) {
+		struct za_context __user *za_ctx =
+			apply_user_offset(user, user->za_offset);
+		err |= preserve_za_context(za_ctx);
+	}
+
+	/* ZT state if present */
+	if (system_supports_sme2() && err == 0 && user->zt_offset) {
+		struct zt_context __user *zt_ctx =
+			apply_user_offset(user, user->zt_offset);
+		err |= preserve_zt_context(zt_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);
+	}
+
+	/* set the "end" magic */
+	if (err == 0) {
+		struct _aarch64_ctx __user *end =
+			apply_user_offset(user, user->end_offset);
+
+		__put_user_error(0, &end->magic, err);
+		__put_user_error(0, &end->size, err);
+	}
+
+	return err;
+}
+
+static long __sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	/*
+	 * Since we stacked the signal on a 128-bit boundary, then 'sp' should
+	 * be word aligned here.
+	 */
+	if (regs->sp & 15)
+		goto badframe;
+
+	frame = (struct rt_sigframe __user *)regs->sp;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+
+	if (restore_sigframe(regs, frame))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->regs[0];
+
+badframe:
+	arm64_notify_segfault(regs->sp);
+	return 0;
+}
+
+static int __setup_rt_frame(int usig, struct ksignal *ksig,
+				sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe_user_layout user;
+	struct rt_sigframe __user *frame;
+	int err = 0;
+
+	fpsimd_signal_preserve_current_state();
+
+	if (get_sigframe(&user, ksig, regs))
+		return 1;
+
+	frame = user.sigframe;
+
+	__put_user_error(0, &frame->uc.uc_flags, err);
+	__put_user_error((typeof(frame->uc.uc_link)) 0,
+			  &frame->uc.uc_link, err);
+
+	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
+	err |= setup_sigframe(&user, regs, set);
+	if (err == 0) {
+		setup_return(regs, &ksig->ka, &user, usig);
+		if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+			err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+			regs->regs[1] = (unsigned long)&frame->info;
+			regs->regs[2] = (unsigned long)&frame->uc;
+		}
+	}
+
+	return err;
+}
+
+#endif /* __ASM_SIGNAL_COMMON_H */
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index c08b47c066bb..a502d485b530 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -34,6 +34,9 @@
 #include <asm/traps.h>
 #include <asm/vdso.h>
+#define get_sigset(s, m) __copy_from_user(s, m, sizeof(*s))
+#define put_sigset(s, m) __copy_to_user(m, s, sizeof(*s))
+
 /*
  * Do a signal return; undo the signal stack. These are aligned to 128-bit.
  */
@@ -41,60 +44,12 @@ struct rt_sigframe {
    struct siginfo info;
    struct ucontext uc;
 };
+struct rt_sigframe_user_layout;
-struct frame_record {
-	u64 fp;
-	u64 lr;
-};
-
-struct rt_sigframe_user_layout {
-	struct rt_sigframe __user *sigframe;
-	struct frame_record __user *next_frame;
-
-	unsigned long size;	/* size of allocated sigframe data */
-	unsigned long limit;	/* largest allowed size */
-
-	unsigned long fpsimd_offset;
-	unsigned long esr_offset;
-	unsigned long sve_offset;
-	unsigned long tpidr2_offset;
-	unsigned long za_offset;
-	unsigned long zt_offset;
-	unsigned long extra_offset;
-	unsigned long end_offset;
-};
-
-#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)
-{
-	const size_t reserved_size =
-		sizeof(user->sigframe->uc.uc_mcontext.__reserved);
-
-	memset(user, 0, sizeof(*user));
-	user->size = offsetof(struct rt_sigframe, uc.uc_mcontext.__reserved);
-
-	user->limit = user->size + reserved_size;
+static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+			 struct rt_sigframe_user_layout *user, int usig);
-	user->limit -= TERMINATOR_SIZE;
-	user->limit -= EXTRA_CONTEXT_SIZE;
-	/* Reserve space for extension and terminator ^ */
-}
-
-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_256K
+#include <asm/signal_common.h>
static int __sigframe_alloc(struct rt_sigframe_user_layout *user,
    		    unsigned long *offset, size_t size, bool extend)
@@ -139,14 +94,14 @@ static int __sigframe_alloc(struct rt_sigframe_user_layout *user,
  * signal frame.  The offset from the signal frame base address to the
  * allocated block is assigned to *offset.
  */
-static int sigframe_alloc(struct rt_sigframe_user_layout *user,
+int sigframe_alloc(struct rt_sigframe_user_layout *user,
    		  unsigned long *offset, size_t size)
 {
    return __sigframe_alloc(user, offset, size, true);
 }
/* Allocate the null terminator record and prevent further allocations */
-static int sigframe_alloc_end(struct rt_sigframe_user_layout *user)
+int sigframe_alloc_end(struct rt_sigframe_user_layout *user)
 {
    int ret;
@@ -163,7 +118,7 @@ static int sigframe_alloc_end(struct rt_sigframe_user_layout *user)
    return 0;
 }
-static void __user *apply_user_offset(
+void __user *apply_user_offset(
    struct rt_sigframe_user_layout const *user, unsigned long offset)
 {
    char __user *base = (char __user *)user->sigframe;
@@ -171,20 +126,7 @@ static void __user *apply_user_offset(
    return base + offset;
 }
-struct user_ctxs {
-	struct fpsimd_context __user *fpsimd;
-	u32 fpsimd_size;
-	struct sve_context __user *sve;
-	u32 sve_size;
-	struct tpidr2_context __user *tpidr2;
-	u32 tpidr2_size;
-	struct za_context __user *za;
-	u32 za_size;
-	struct zt_context __user *zt;
-	u32 zt_size;
-};
-
-static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
+int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
 {
    struct user_fpsimd_state const *fpsimd =
    	&current->thread.uw.fpsimd_state;
@@ -202,7 +144,7 @@ static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
    return err ? -EFAULT : 0;
 }
-static int restore_fpsimd_context(struct user_ctxs *user)
+int restore_fpsimd_context(struct user_ctxs *user)
 {
    struct user_fpsimd_state fpsimd;
    int err = 0;
@@ -230,7 +172,7 @@ static int restore_fpsimd_context(struct user_ctxs *user)
#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)];
@@ -270,7 +212,7 @@ 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 = 0;
    unsigned int vl, vq;
@@ -363,20 +305,17 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
#else /* ! CONFIG_ARM64_SVE */
-static int restore_sve_fpsimd_context(struct user_ctxs *user)
+int restore_sve_fpsimd_context(struct user_ctxs *user)
 {
    WARN_ON_ONCE(1);
    return -EINVAL;
 }
-/* Turn any non-optimised out attempts to use this into a link error: */
-extern int preserve_sve_context(void __user *ctx);
-
 #endif /* ! CONFIG_ARM64_SVE */
#ifdef CONFIG_ARM64_SME
-static int preserve_tpidr2_context(struct tpidr2_context __user *ctx)
+int preserve_tpidr2_context(struct tpidr2_context __user *ctx)
 {
    int err = 0;
@@ -389,7 +328,7 @@ static int preserve_tpidr2_context(struct tpidr2_context __user *ctx)
    return err;
 }
-static int restore_tpidr2_context(struct user_ctxs *user)
+int restore_tpidr2_context(struct user_ctxs *user)
 {
    u64 tpidr2_el0;
    int err = 0;
@@ -404,7 +343,7 @@ static int restore_tpidr2_context(struct user_ctxs *user)
    return err;
 }
-static int preserve_za_context(struct za_context __user *ctx)
+int preserve_za_context(struct za_context __user *ctx)
 {
    int err = 0;
    u16 reserved[ARRAY_SIZE(ctx->__reserved)];
@@ -439,7 +378,7 @@ static int preserve_za_context(struct za_context __user *ctx)
    return err ? -EFAULT : 0;
 }
-static int restore_za_context(struct user_ctxs *user)
+int restore_za_context(struct user_ctxs *user)
 {
    int err = 0;
    unsigned int vq;
@@ -495,7 +434,7 @@ static int restore_za_context(struct user_ctxs *user)
    return 0;
 }
-static int preserve_zt_context(struct zt_context __user *ctx)
+int preserve_zt_context(struct zt_context __user *ctx)
 {
    int err = 0;
    u16 reserved[ARRAY_SIZE(ctx->__reserved)];
@@ -524,7 +463,7 @@ static int preserve_zt_context(struct zt_context __user *ctx)
    return err ? -EFAULT : 0;
 }
-static int restore_zt_context(struct user_ctxs *user)
+int restore_zt_context(struct user_ctxs *user)
 {
    int err;
    u16 nregs;
@@ -574,7 +513,7 @@ extern int restore_zt_context(struct user_ctxs *user);
#endif /* ! CONFIG_ARM64_SME */
-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)
 {
@@ -766,89 +705,10 @@ static int __parse_user_sigcontext(struct user_ctxs *user,
    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)
-{
-	sigset_t set;
-	int i, err;
-	struct user_ctxs user;
-
-	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
-	if (err == 0)
-		set_current_blocked(&set);
-
-	for (i = 0; i < 31; i++)
-		__get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
-				 err);
-	__get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
-	__get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
-	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
-
-	/*
-	 * Avoid sys_rt_sigreturn() restarting.
-	 */
-	forget_syscall(regs);
-
-	err |= !valid_user_regs(&regs->user_regs, current);
-	if (err == 0)
-		err = parse_user_sigcontext(&user, sf);
-
-	if (err == 0 && system_supports_fpsimd()) {
-		if (!user.fpsimd)
-			return -EINVAL;
-
-		if (user.sve)
-			err = restore_sve_fpsimd_context(&user);
-		else
-			err = restore_fpsimd_context(&user);
-	}
-
-	if (err == 0 && system_supports_tpidr2() && user.tpidr2)
-		err = restore_tpidr2_context(&user);
-
-	if (err == 0 && system_supports_sme() && user.za)
-		err = restore_za_context(&user);
-
-	if (err == 0 && system_supports_sme2() && user.zt)
-		err = restore_zt_context(&user);
-
-	return err;
-}
-
 SYSCALL_DEFINE0(rt_sigreturn)
 {
    struct pt_regs *regs = current_pt_regs();
-	struct rt_sigframe __user *frame;
-
-	/* Always make any pending restarted system calls return -EINTR */
-	current->restart_block.fn = do_no_restart_syscall;
-
-	/*
-	 * Since we stacked the signal on a 128-bit boundary, then 'sp' should
-	 * be word aligned here.
-	 */
-	if (regs->sp & 15)
-		goto badframe;
-
-	frame = (struct rt_sigframe __user *)regs->sp;
-
-	if (!access_ok(frame, sizeof (*frame)))
-		goto badframe;
-
-	if (restore_sigframe(regs, frame))
-		goto badframe;
-
-	if (restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
-	return regs->regs[0];
-
-badframe:
-	arm64_notify_segfault(regs->sp);
-	return 0;
+	return __sys_rt_sigreturn(regs);
 }
/*
@@ -858,8 +718,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
  *	this task; otherwise, generates a layout for the current state
  *	of the task.
  */
-static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
-				 bool add_all)
+int setup_sigframe_layout(struct rt_sigframe_user_layout *user, bool add_all)
 {
    int err;
@@ -934,144 +793,48 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
    return sigframe_alloc_end(user);
 }
-static int setup_sigframe(struct rt_sigframe_user_layout *user,
-			  struct pt_regs *regs, sigset_t *set)
+int setup_extra_context(char __user *sfp, unsigned long sf_size,
+			char __user *extrap)
 {
-	int i, err = 0;
-	struct rt_sigframe __user *sf = user->sigframe;
-
-	/* set up the stack frame for unwinding */
-	__put_user_error(regs->regs[29], &user->next_frame->fp, err);
-	__put_user_error(regs->regs[30], &user->next_frame->lr, err);
-
-	for (i = 0; i < 31; i++)
-		__put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
-				 err);
-	__put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
-	__put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
-	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
-
-	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
-
-	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
-
-	if (err == 0 && system_supports_fpsimd()) {
-		struct fpsimd_context __user *fpsimd_ctx =
-			apply_user_offset(user, user->fpsimd_offset);
-		err |= preserve_fpsimd_context(fpsimd_ctx);
-	}
-
-	/* fault information, if valid */
-	if (err == 0 && user->esr_offset) {
-		struct esr_context __user *esr_ctx =
-			apply_user_offset(user, user->esr_offset);
-
-		__put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err);
-		__put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err);
-		__put_user_error(current->thread.fault_code, &esr_ctx->esr, err);
-	}
-
-	/* Scalable Vector Extension state (including streaming), if present */
-	if ((system_supports_sve() || system_supports_sme()) &&
-	    err == 0 && user->sve_offset) {
-		struct sve_context __user *sve_ctx =
-			apply_user_offset(user, user->sve_offset);
-		err |= preserve_sve_context(sve_ctx);
-	}
-
-	/* TPIDR2 if supported */
-	if (system_supports_tpidr2() && err == 0) {
-		struct tpidr2_context __user *tpidr2_ctx =
-			apply_user_offset(user, user->tpidr2_offset);
-		err |= preserve_tpidr2_context(tpidr2_ctx);
-	}
-
-	/* ZA state if present */
-	if (system_supports_sme() && err == 0 && user->za_offset) {
-		struct za_context __user *za_ctx =
-			apply_user_offset(user, user->za_offset);
-		err |= preserve_za_context(za_ctx);
-	}
-
-	/* ZT state if present */
-	if (system_supports_sme2() && err == 0 && user->zt_offset) {
-		struct zt_context __user *zt_ctx =
-			apply_user_offset(user, user->zt_offset);
-		err |= preserve_zt_context(zt_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;
+	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;
+	extra = (struct extra_context __user *)extrap;
+	extrap += EXTRA_CONTEXT_SIZE;
-		end = (struct _aarch64_ctx __user *)userp;
-		userp += TERMINATOR_SIZE;
+	end = (struct _aarch64_ctx __user *)extrap;
+	extrap += 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);
-	}
+	/*
+	 * extra_datap is just written to the signal frame.
+	 * The value gets cast back to a void __user *
+	 * during sigreturn.
+	 */
+	extra_datap = (__force u64)extrap;
+	extra_size = sfp + round_up(sf_size, 16) - extrap;
-	/* set the "end" magic */
-	if (err == 0) {
-		struct _aarch64_ctx __user *end =
-			apply_user_offset(user, user->end_offset);
+	__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);
-		__put_user_error(0, &end->magic, err);
-		__put_user_error(0, &end->size, err);
-	}
+	/* Add the terminator */
+	__put_user_error(0, &end->magic, err);
+	__put_user_error(0, &end->size, err);
return err;
 }
-static int get_sigframe(struct rt_sigframe_user_layout *user,
-			 struct ksignal *ksig, struct pt_regs *regs)
+void __setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+		    struct rt_sigframe_user_layout *user, int usig)
 {
-	unsigned long sp, sp_top;
-	int err;
-
-	init_user_layout(user);
-	err = setup_sigframe_layout(user, false);
-	if (err)
-		return err;
-
-	sp = sp_top = sigsp(regs->sp, ksig);
-
-	sp = round_down(sp - sizeof(struct frame_record), 16);
-	user->next_frame = (struct frame_record __user *)sp;
-
-	sp = round_down(sp, 16) - sigframe_size(user);
-	user->sigframe = (struct rt_sigframe __user *)sp;
-
-	/*
-	 * Check that we can actually write to the signal frame.
-	 */
-	if (!access_ok(user->sigframe, sp_top - sp))
-		return -EFAULT;
-
-	return 0;
+	regs->regs[0] = usig;
+	regs->sp = (unsigned long)user->sigframe;
+	regs->regs[29] = (unsigned long)&user->next_frame->fp;
+	regs->pc = (unsigned long)ka->sa.sa_handler;
 }
static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
@@ -1079,10 +842,7 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 {
    __sigrestore_t sigtramp;
-	regs->regs[0] = usig;
-	regs->sp = (unsigned long)user->sigframe;
-	regs->regs[29] = (unsigned long)&user->next_frame->fp;
-	regs->pc = (unsigned long)ka->sa.sa_handler;
+	__setup_return(regs, ka, user, usig);
/*
     * Signal delivery is a (wacky) indirect function call in
@@ -1133,32 +893,7 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set,
    		  struct pt_regs *regs)
 {
-	struct rt_sigframe_user_layout user;
-	struct rt_sigframe __user *frame;
-	int err = 0;
-
-	fpsimd_signal_preserve_current_state();
-
-	if (get_sigframe(&user, ksig, regs))
-		return 1;
-
-	frame = user.sigframe;
-
-	__put_user_error(0, &frame->uc.uc_flags, err);
-	__put_user_error(NULL, &frame->uc.uc_link, err);
-
-	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
-	err |= setup_sigframe(&user, regs, set);
-	if (err == 0) {
-		setup_return(regs, &ksig->ka, &user, usig);
-		if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
-			err |= copy_siginfo_to_user(&frame->info, &ksig->info);
-			regs->regs[1] = (unsigned long)&frame->info;
-			regs->regs[2] = (unsigned long)&frame->uc;
-		}
-	}
-
-	return err;
+	return __setup_rt_frame(usig, ksig, set, regs);
 }
static void setup_restart_syscall(struct pt_regs *regs)
-- 
2.34.1


    

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[PATCH OLK-6.6 v2 16/31] arm64: signal: share lp64 signal structures and routines to ilp32