syscall.h: add syscall_set_arguments()

This function is going to be needed on all HAVE_ARCH_TRACEHOOK
architectures to implement PTRACE_SET_SYSCALL_INFO API.

This partially reverts commit 7962c2eddbfe ("arch: remove unused function
syscall_set_arguments()") by reusing some of old syscall_set_arguments()
implementations.

[nathan@kernel.org: fix compile time fortify checks]
  Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162
Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>	[mips]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexey Gladkov (Intel) <legion@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index 056aa1b713e2..f1926ce30d4b 100644
--- a/arch/mips/include/asm/syscall.h
+++ b/arch/mips/include/asm/syscall.h
@@ -74,6 +74,23 @@ static inline void mips_get_syscall_arg(unsigned long *arg,
 #endif
 }
 
+static inline void mips_set_syscall_arg(unsigned long *arg,
+	struct task_struct *task, struct pt_regs *regs, unsigned int n)
+{
+#ifdef CONFIG_32BIT
+	switch (n) {
+	case 0: case 1: case 2: case 3:
+		regs->regs[4 + n] = *arg;
+		return;
+	case 4: case 5: case 6: case 7:
+		*arg = regs->args[n] = *arg;
+		return;
+	}
+#else
+	regs->regs[4 + n] = *arg;
+#endif
+}
+
 static inline long syscall_get_error(struct task_struct *task,
 				     struct pt_regs *regs)
 {
@@ -120,6 +137,17 @@ static inline void syscall_get_arguments(struct task_struct *task,
 		mips_get_syscall_arg(args++, task, regs, i++);
 }
 
+static inline void syscall_set_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 unsigned long *args)
+{
+	unsigned int i = 0;
+	unsigned int n = 6;
+
+	while (n--)
+		mips_set_syscall_arg(args++, task, regs, i++);
+}
+
 extern const unsigned long sys_call_table[];
 extern const unsigned long sys32_call_table[];
 extern const unsigned long sysn32_call_table[];