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
......@@ -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:
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -1640,6 +1640,10 @@ int kvm_arch_init(void *opaque)
return -ENODEV;
}
if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE))
kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
"Only trusted guests should be used on this system.\n");
for_each_online_cpu(cpu) {
smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1);
if (ret < 0) {
......
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