Commit dd105d64 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 

Pull arm64 fixes from Catalin Marinas:

 - Allow booting of late secondary CPUs affected by erratum 1418040
   (currently they are parked if none of the early CPUs are affected by
   this erratum).

 - Add the 32-bit vdso Makefile to the vdso_install rule so that 'make
   vdso_install' installs the 32-bit compat vdso when it is compiled.

 - Print a warning that untrusted guests without a CPU erratum
   workaround (Cortex-A57 832075) may deadlock the affected system.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  ARM64: vdso32: Install vdso32 from vdso_install
  KVM: arm64: Print warning when cpu erratum can cause guests to deadlock
  arm64: Allow booting of late CPUs affected by erratum 1418040
  arm64: Move handling of erratum 1418040 into C code
parents d57ce840 8d75785a

arch/arm64/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ zinstall install: 
PHONY += vdso_install

vdso_install:

	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@

	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@



# We use MRPROPER_FILES and CLEAN_FILES now

archclean:

arch/arm64/kernel/cpu_errata.c

+2 −0
Original line number Diff line number Diff line
@@ -910,6 +910,8 @@ const struct arm64_cpu_capabilities arm64_errata[] = { 
		.desc = "ARM erratum 1418040",

		.capability = ARM64_WORKAROUND_1418040,

		ERRATA_MIDR_RANGE_LIST(erratum_1418040_list),

		.type = (ARM64_CPUCAP_SCOPE_LOCAL_CPU |

			 ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU),

	},

#endif

#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_AT

arch/arm64/kernel/entry.S

+0 −21
Original line number Diff line number Diff line
@@ -170,19 +170,6 @@ alternative_cb_end 
	stp	x28, x29, [sp, #16 * 14]



	.if	\el == 0

	.if	\regsize == 32

	/*

	 * If we're returning from a 32-bit task on a system affected by

	 * 1418040 then re-enable userspace access to the virtual counter.

	 */

#ifdef CONFIG_ARM64_ERRATUM_1418040

alternative_if ARM64_WORKAROUND_1418040

	mrs	x0, cntkctl_el1

	orr	x0, x0, #2	// ARCH_TIMER_USR_VCT_ACCESS_EN

	msr	cntkctl_el1, x0

alternative_else_nop_endif

#endif

	.endif

	clear_gp_regs

	mrs	x21, sp_el0

	ldr_this_cpu	tsk, __entry_task, x20
@@ -294,14 +281,6 @@ alternative_else_nop_endif 
	tst	x22, #PSR_MODE32_BIT		// native task?

	b.eq	3f



#ifdef CONFIG_ARM64_ERRATUM_1418040

alternative_if ARM64_WORKAROUND_1418040

	mrs	x0, cntkctl_el1

	bic	x0, x0, #2			// ARCH_TIMER_USR_VCT_ACCESS_EN

	msr	cntkctl_el1, x0

alternative_else_nop_endif

#endif



#ifdef CONFIG_ARM64_ERRATUM_845719

alternative_if ARM64_WORKAROUND_845719

#ifdef CONFIG_PID_IN_CONTEXTIDR

arch/arm64/kernel/process.c

+34 −0
Original line number Diff line number Diff line
@@ -515,6 +515,39 @@ static void entry_task_switch(struct task_struct *next) 
	__this_cpu_write(__entry_task, next);

}



/*

 * ARM erratum 1418040 handling, affecting the 32bit view of CNTVCT.

 * Assuming the virtual counter is enabled at the beginning of times:

 *

 * - disable access when switching from a 64bit task to a 32bit task

 * - enable access when switching from a 32bit task to a 64bit task

 */

static void erratum_1418040_thread_switch(struct task_struct *prev,

					  struct task_struct *next)

{

	bool prev32, next32;

	u64 val;



	if (!(IS_ENABLED(CONFIG_ARM64_ERRATUM_1418040) &&

	      cpus_have_const_cap(ARM64_WORKAROUND_1418040)))

		return;



	prev32 = is_compat_thread(task_thread_info(prev));

	next32 = is_compat_thread(task_thread_info(next));



	if (prev32 == next32)

		return;



	val = read_sysreg(cntkctl_el1);



	if (!next32)

		val |= ARCH_TIMER_USR_VCT_ACCESS_EN;

	else

		val &= ~ARCH_TIMER_USR_VCT_ACCESS_EN;



	write_sysreg(val, cntkctl_el1);

}



/*

 * Thread switching.

 */
@@ -530,6 +563,7 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, 
	entry_task_switch(next);

	uao_thread_switch(next);

	ssbs_thread_switch(next);

	erratum_1418040_thread_switch(prev, next);



	/*

	 * Complete any pending TLB or cache maintenance on this CPU in case

arch/arm64/kernel/vdso32/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -208,7 +208,7 @@ quiet_cmd_vdsosym = VDSOSYM $@ 
      cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@



# Install commands for the unstripped file

quiet_cmd_vdso_install = INSTALL $@

quiet_cmd_vdso_install = INSTALL32 $@

      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so



vdso.so: $(obj)/vdso.so.dbg

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