From: Will Deacon <will@kernel.org>
Date: Thu, 12 Sep 2024 12:44:03 +0000 (+0100)
Subject: Merge branch 'for-next/timers' into for-next/core
X-Git-Tag: v6.12-rc1~221^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=75078ba2b38a38d94017bd334f71aaed205e30a4;p=thirdparty%2Fkernel%2Flinux.git

Merge branch 'for-next/timers' into for-next/core

* for-next/timers:
  arm64: Implement prctl(PR_{G,S}ET_TSC)
---

75078ba2b38a38d94017bd334f71aaed205e30a4
diff --cc arch/arm64/kernel/process.c
index f365b033a6495,1b6bbf839bb5e..0540653fbf382
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@@ -500,24 -492,35 +504,46 @@@ static void update_cntkctl_el1(struct t
  		sysreg_clear_set(cntkctl_el1, 0, ARCH_TIMER_USR_VCT_ACCESS_EN);
  }
  
- static void erratum_1418040_new_exec(void)
+ static void cntkctl_thread_switch(struct task_struct *prev,
+ 				  struct task_struct *next)
+ {
+ 	if ((read_ti_thread_flags(task_thread_info(prev)) &
+ 	     (_TIF_32BIT | _TIF_TSC_SIGSEGV)) !=
+ 	    (read_ti_thread_flags(task_thread_info(next)) &
+ 	     (_TIF_32BIT | _TIF_TSC_SIGSEGV)))
+ 		update_cntkctl_el1(next);
+ }
+ 
+ static int do_set_tsc_mode(unsigned int val)
  {
+ 	bool tsc_sigsegv;
+ 
+ 	if (val == PR_TSC_SIGSEGV)
+ 		tsc_sigsegv = true;
+ 	else if (val == PR_TSC_ENABLE)
+ 		tsc_sigsegv = false;
+ 	else
+ 		return -EINVAL;
+ 
  	preempt_disable();
- 	erratum_1418040_thread_switch(current);
+ 	update_thread_flag(TIF_TSC_SIGSEGV, tsc_sigsegv);
+ 	update_cntkctl_el1(current);
  	preempt_enable();
+ 
+ 	return 0;
  }
  
 +static void permission_overlay_switch(struct task_struct *next)
 +{
 +	if (!system_supports_poe())
 +		return;
 +
 +	current->thread.por_el0 = read_sysreg_s(SYS_POR_EL0);
 +	if (current->thread.por_el0 != next->thread.por_el0) {
 +		write_sysreg_s(next->thread.por_el0, SYS_POR_EL0);
 +	}
 +}
 +
  /*
   * __switch_to() checks current->thread.sctlr_user as an optimisation. Therefore
   * this function must be called with preemption disabled and the update to
@@@ -551,9 -554,8 +577,9 @@@ struct task_struct *__switch_to(struct 
  	contextidr_thread_switch(next);
  	entry_task_switch(next);
  	ssbs_thread_switch(next);
- 	erratum_1418040_thread_switch(next);
+ 	cntkctl_thread_switch(prev, next);
  	ptrauth_thread_switch_user(next);
 +	permission_overlay_switch(next);
  
  	/*
  	 * Complete any pending TLB or cache maintenance on this CPU in case