kvx: Directly use the linux headers for the register definitions

Summary:
In musl we defined a user_regs_struct that contains the registers
structure as provided by the kernel via ptrace. But the same define is
already in the Linux kernel (and the header is already provided via the
linux-headers package). So, no need to re-define it in musl (in user.h).

Ref T18986

Test Plan: CI

Reviewers: O51 Linux Coolidge!

Subscribers: #linux_coolidge_cc

Maniphest Tasks: T18986

Differential Revision: https://phab.kalray.eu/D26038

src/linux/kvx/arch_regs.c

@@ -9,4 +9,4 @@
 static struct user_regs_struct kvx_regs;
 #define ARCH_REGS_FOR_GETREGSET kvx_regs
 #define ARCH_PC_REG kvx_regs.spc
-#define ARCH_SP_REG kvx_regs.gpr_regs[12]
+#define ARCH_SP_REG kvx_regs.sp

src/linux/kvx/get_error.c

@@ -11,10 +11,10 @@
 static void
 arch_get_error(struct tcb *tcp, const bool check_errno)
 {
-	if (check_errno && is_negated_errno(kvx_regs.gpr_regs[0])) {
+	if (check_errno && is_negated_errno(kvx_regs.r0)) {
 		tcp->u_rval = -1;
-		tcp->u_error = -kvx_regs.gpr_regs[0];
+		tcp->u_error = -kvx_regs.r0;
 	} else {
-		tcp->u_rval = kvx_regs.gpr_regs[0];
+		tcp->u_rval = kvx_regs.r0;
 	}
 }

src/linux/kvx/get_scno.c

@@ -10,6 +10,6 @@
 static int
 arch_get_scno(struct tcb *tcp)
 {
-	tcp->scno = kvx_regs.gpr_regs[6];
+	tcp->scno = kvx_regs.r6;
 	return 1;
 }

src/linux/kvx/get_syscall_args.c

@@ -10,12 +10,12 @@
 static int
 arch_get_syscall_args(struct tcb *tcp)
 {
-	tcp->u_arg[0] = kvx_regs.gpr_regs[0];
-	tcp->u_arg[1] = kvx_regs.gpr_regs[1];
-	tcp->u_arg[2] = kvx_regs.gpr_regs[2];
-	tcp->u_arg[3] = kvx_regs.gpr_regs[3];
-	tcp->u_arg[4] = kvx_regs.gpr_regs[4];
-	tcp->u_arg[5] = kvx_regs.gpr_regs[5];
+	tcp->u_arg[0] = kvx_regs.r0;
+	tcp->u_arg[1] = kvx_regs.r1;
+	tcp->u_arg[2] = kvx_regs.r2;
+	tcp->u_arg[3] = kvx_regs.r3;
+	tcp->u_arg[4] = kvx_regs.r4;
+	tcp->u_arg[5] = kvx_regs.r5;
 
 	return 1;
 }

src/linux/kvx/set_error.c

@@ -9,13 +9,13 @@
 static int
 arch_set_error(struct tcb *tcp)
 {
-	kvx_regs.gpr_regs[0] = -tcp->u_error;
+	kvx_regs.r0 = -tcp->u_error;
 	return set_regs(tcp->pid);
 }
 
 static int
 arch_set_success(struct tcb *tcp)
 {
-	kvx_regs.gpr_regs[0] = tcp->u_rval;
+	kvx_regs.r0 = tcp->u_rval;
 	return set_regs(tcp->pid);
 }

src/linux/kvx/set_scno.c

@@ -9,6 +9,6 @@
 static int
 arch_set_scno(struct tcb *tcp, kernel_ulong_t scno)
 {
-	kvx_regs.gpr_regs[6] = scno;
+	kvx_regs.r6 = scno;
 	return set_regs(tcp->pid);
 }