[PATCH 06/21] arm64: Store 'current' in TPIDRRO_EL0 instead of SP_EL0

@@ -587,7 +587,7 @@ alternative_else_nop_endif
  * Return the current task_struct.
  */
 	.macro	get_current_task, rd
-	mrs	\rd, sp_el0
+	mrs	\rd, tpidrro_el0
 	.endm
 
 /*

@@ -14,11 +14,11 @@ struct task_struct;
  */
 static __always_inline struct task_struct *get_current(void)
 {
-	unsigned long sp_el0;
+	unsigned long tpidrro_el0;
 
-	asm ("mrs %0, sp_el0" : "=r" (sp_el0));
+	asm ("mrs %0, tpidrro_el0" : "=r" (tpidrro_el0));
 
-	return (struct task_struct *)sp_el0;
+	return (struct task_struct *)tpidrro_el0;
 }
 
 #define current get_current()

@@ -81,9 +81,9 @@
 	/* Stash the original SP (minus PT_REGS_SIZE) in tpidr_el0. */
 	msr	tpidr_el0, x0
 
-	/* Recover the original x0 value and stash it in tpidrro_el0 */
+	/* Recover the original x0 value and stash it in sp_el0 */
 	sub	x0, sp, x0
-	msr	tpidrro_el0, x0
+	msr	sp_el0, x0
 
 	/* Switch to the overflow stack */
 	adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0

@@ -99,7 +99,7 @@
 
 	/* We were already on the overflow stack. Restore sp/x0 and carry on. */
 	sub	sp, sp, x0
-	mrs	x0, tpidrro_el0
+	mrs	x0, sp_el0
 	b	el\el\ht\()_\regsize\()_\label
 	.endif
 .org .Lventry_start\@ + 128	// Did we overflow the ventry slot?

@@ -226,7 +226,7 @@ alternative_cb_end
 	clear_gp_regs
 	mrs	x21, sp_el0
 	ldr_this_cpu	tsk, __entry_task, x20
-	msr	sp_el0, tsk
+	msr	tpidrro_el0, tsk
 
 	/*
 	 * Ensure MDSCR_EL1.SS is clear, since we can unmask debug exceptions

@@ -548,7 +548,7 @@ SYM_CODE_START_LOCAL(__bad_stack)
 	 */
 
 	/* Restore the original x0 value */
-	mrs	x0, tpidrro_el0
+	mrs	x0, sp_el0
 
 	/*
 	 * Store the original GPRs to the new stack. The orginal SP (minus

@@ -843,7 +843,7 @@ SYM_FUNC_START(cpu_switch_to)
 	ldp	x29, x9, [x8], #16
 	ldr	lr, [x8]
 	mov	sp, x9
-	msr	sp_el0, x1
+	msr	tpidrro_el0, x1
 	ptrauth_keys_install_kernel x1, x8, x9, x10
 	scs_save x0
 	scs_load_current

@@ -1031,11 +1031,11 @@ SYM_CODE_START(__sdei_asm_handler)
 
 	/*
 	 * We may have interrupted userspace, or a guest, or exit-from or
-	 * return-to either of these. We can't trust sp_el0, restore it.
+	 * return-to either of these. We can't trust tpidrro_el0, restore it.
 	 */
-	mrs	x28, sp_el0
+	mrs	x28, tpidrro_el0
 	ldr_this_cpu	dst=x0, sym=__entry_task, tmp=x1
-	msr	sp_el0, x0
+	msr	tpidrro_el0, x0
 
 	/* If we interrupted the kernel point to the previous stack/frame. */
 	and     x0, x3, #0xc

@@ -1051,7 +1051,7 @@ SYM_CODE_START(__sdei_asm_handler)
 	mov	x1, x19
 	bl	__sdei_handler
 
-	msr	sp_el0, x28
+	msr	tpidrro_el0, x28
 	/* restore regs >x17 that we clobbered */
 	mov	x4, x19         // keep x4 for __sdei_asm_exit_trampoline
 	ldp	x28, x29, [x4, #SDEI_EVENT_INTREGS + 16 * 14]

@@ -193,7 +193,7 @@ SYM_CODE_END(preserve_boot_args)
 	 * for consistency with user tasks and kthreads.
 	 */
 	.macro	init_cpu_task tsk, tmp1, tmp2
-	msr	sp_el0, \tsk
+	msr	tpidrro_el0, \tsk
 
 	ldr	\tmp1, [\tsk, #TSK_STACK]
 	add	sp, \tmp1, #THREAD_SIZE

@@ -551,8 +551,9 @@ static void ssbs_thread_switch(struct task_struct *next)
 }
 
 /*
- * We store our current task in sp_el0, which is clobbered by userspace. Keep a
- * shadow copy so that we can restore this upon entry from userspace.
+ * We store our current task in tpidrro_el0, which is clobbered when returning
+ * to userspace. Keep a shadow copy so that we can restore this upon entry from
+ * userspace.
  *
  * This is *only* for exception entry from EL0, and is not valid until we
  * __switch_to() a user task.

@@ -1694,7 +1694,7 @@ static int build_insn(const struct bpf_verifier_env *env, const struct bpf_insn
 		if (insn->src_reg == 0 && insn->imm == BPF_FUNC_get_smp_processor_id) {
 			cpu_offset = offsetof(struct thread_info, cpu);
 
-			emit(A64_MRS_SP_EL0(tmp), ctx);
+			emit(A64_MRS_TPIDRRO_EL0(tmp), ctx);
 			if (is_lsi_offset(cpu_offset, 2)) {
 				emit(A64_LDR32I(r0, tmp, cpu_offset), ctx);
 			} else {

@@ -1707,7 +1707,7 @@ static int build_insn(const struct bpf_verifier_env *env, const struct bpf_insn
 		/* Implement helper call to bpf_get_current_task/_btf() inline */
 		if (insn->src_reg == 0 && (insn->imm == BPF_FUNC_get_current_task ||
 					   insn->imm == BPF_FUNC_get_current_task_btf)) {
-			emit(A64_MRS_SP_EL0(r0), ctx);
+			emit(A64_MRS_TPIDRRO_EL0(r0), ctx);
 			break;
 		}