3 files changed, 33 insertions, 2 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index a8b066dbbf48..e1b91bffa988 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -284,9 +284,13 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 	nr &= __SYSCALL_MASK;
 	if (likely(nr < NR_syscalls)) {
 		nr = array_index_nospec(nr, NR_syscalls);
+#ifdef CONFIG_SYSCALL_PTREGS
+		regs->ax = sys_call_table[nr](regs);
+#else
 		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
+#endif
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index c176d2fab1da..6197850adf91 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,19 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
+#ifdef CONFIG_SYSCALL_PTREGS
+/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
+extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+#else /* CONFIG_SYSCALL_PTREGS */
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
 #define __SYSCALL_64(nr, sym, qual) [nr] = sym,
 
-extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*
 	 * Smells like a compiler bug -- it doesn't work
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 317be365bce3..05eebbf9b989 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,6 +127,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	int vsyscall_nr, syscall_nr, tmp;
 	int prev_sig_on_uaccess_err;
 	long ret;
+#ifdef CONFIG_SYSCALL_PTREGS
+	unsigned long orig_dx;
+#endif
 
 	/*
 	 * No point in checking CS -- the only way to get here is a user mode
@@ -227,19 +230,38 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di and regs->si on its own */
+		ret = sys_gettimeofday(regs);
+#else
 		ret = sys_gettimeofday(
 			(struct timeval __user *)regs->di,
 			(struct timezone __user *)regs->si);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 1:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di on its own */
+		ret = sys_time(regs);
+#else
 		ret = sys_time((time_t __user *)regs->di);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 2:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* while we could clobber regs->dx, we didn't in the past... */
+		orig_dx = regs->dx;
+		regs->dx = 0;
+		/* this decodes regs->di, regs->si and regs->dx on its own */
+		ret = sys_getcpu(regs);
+		regs->dx = orig_dx;
+#else
 		ret = sys_getcpu((unsigned __user *)regs->di,
 				 (unsigned __user *)regs->si,
 				 NULL);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 	}