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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-14 10:10:55 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-14 10:10:55 +0200
commitfccee0baced04636952cd580ddee4bb8cbb9544c (patch)
tree80e25c0e100246357bd0c0a93feb1bf2e5e5bd1d /arch/x86/kernel
parenta5a6d2753e7ec18a34bd21190b50ee7f085f4daf (diff)
parent856deb866d16e29bd65952e0289066f6078af773 (diff)
Merge 5.9-rc5 into usb-next
We need the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/kvm.c26
-rw-r--r--arch/x86/kernel/traps.c65
2 files changed, 51 insertions, 40 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 08320b0b2b27..1b51b727b140 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -270,9 +270,8 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
{
struct pt_regs *old_regs = set_irq_regs(regs);
u32 token;
- irqentry_state_t state;
- state = irqentry_enter(regs);
+ ack_APIC_irq();
inc_irq_stat(irq_hv_callback_count);
@@ -283,7 +282,6 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
}
- irqentry_exit(regs, state);
set_irq_regs(old_regs);
}
@@ -654,7 +652,6 @@ static void __init kvm_guest_init(void)
}
if (pv_tlb_flush_supported()) {
- pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
pv_ops.mmu.tlb_remove_table = tlb_remove_table;
pr_info("KVM setup pv remote TLB flush\n");
}
@@ -767,6 +764,14 @@ static __init int activate_jump_labels(void)
}
arch_initcall(activate_jump_labels);
+static void kvm_free_pv_cpu_mask(void)
+{
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu)
+ free_cpumask_var(per_cpu(__pv_cpu_mask, cpu));
+}
+
static __init int kvm_alloc_cpumask(void)
{
int cpu;
@@ -785,11 +790,20 @@ static __init int kvm_alloc_cpumask(void)
if (alloc)
for_each_possible_cpu(cpu) {
- zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, cpu),
- GFP_KERNEL, cpu_to_node(cpu));
+ if (!zalloc_cpumask_var_node(
+ per_cpu_ptr(&__pv_cpu_mask, cpu),
+ GFP_KERNEL, cpu_to_node(cpu))) {
+ goto zalloc_cpumask_fail;
+ }
}
+ apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
+ pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
return 0;
+
+zalloc_cpumask_fail:
+ kvm_free_pv_cpu_mask();
+ return -ENOMEM;
}
arch_initcall(kvm_alloc_cpumask);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 1f66d2d1e998..81a2fb711091 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -729,20 +729,9 @@ static bool is_sysenter_singlestep(struct pt_regs *regs)
#endif
}
-static __always_inline void debug_enter(unsigned long *dr6, unsigned long *dr7)
+static __always_inline unsigned long debug_read_clear_dr6(void)
{
- /*
- * Disable breakpoints during exception handling; recursive exceptions
- * are exceedingly 'fun'.
- *
- * Since this function is NOKPROBE, and that also applies to
- * HW_BREAKPOINT_X, we can't hit a breakpoint before this (XXX except a
- * HW_BREAKPOINT_W on our stack)
- *
- * Entry text is excluded for HW_BP_X and cpu_entry_area, which
- * includes the entry stack is excluded for everything.
- */
- *dr7 = local_db_save();
+ unsigned long dr6;
/*
* The Intel SDM says:
@@ -755,15 +744,12 @@ static __always_inline void debug_enter(unsigned long *dr6, unsigned long *dr7)
*
* Keep it simple: clear DR6 immediately.
*/
- get_debugreg(*dr6, 6);
+ get_debugreg(dr6, 6);
set_debugreg(0, 6);
/* Filter out all the reserved bits which are preset to 1 */
- *dr6 &= ~DR6_RESERVED;
-}
+ dr6 &= ~DR6_RESERVED;
-static __always_inline void debug_exit(unsigned long dr7)
-{
- local_db_restore(dr7);
+ return dr6;
}
/*
@@ -863,6 +849,18 @@ out:
static __always_inline void exc_debug_kernel(struct pt_regs *regs,
unsigned long dr6)
{
+ /*
+ * Disable breakpoints during exception handling; recursive exceptions
+ * are exceedingly 'fun'.
+ *
+ * Since this function is NOKPROBE, and that also applies to
+ * HW_BREAKPOINT_X, we can't hit a breakpoint before this (XXX except a
+ * HW_BREAKPOINT_W on our stack)
+ *
+ * Entry text is excluded for HW_BP_X and cpu_entry_area, which
+ * includes the entry stack is excluded for everything.
+ */
+ unsigned long dr7 = local_db_save();
bool irq_state = idtentry_enter_nmi(regs);
instrumentation_begin();
@@ -883,6 +881,8 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs,
instrumentation_end();
idtentry_exit_nmi(regs, irq_state);
+
+ local_db_restore(dr7);
}
static __always_inline void exc_debug_user(struct pt_regs *regs,
@@ -894,6 +894,15 @@ static __always_inline void exc_debug_user(struct pt_regs *regs,
*/
WARN_ON_ONCE(!user_mode(regs));
+ /*
+ * NB: We can't easily clear DR7 here because
+ * idtentry_exit_to_usermode() can invoke ptrace, schedule, access
+ * user memory, etc. This means that a recursive #DB is possible. If
+ * this happens, that #DB will hit exc_debug_kernel() and clear DR7.
+ * Since we're not on the IST stack right now, everything will be
+ * fine.
+ */
+
irqentry_enter_from_user_mode(regs);
instrumentation_begin();
@@ -907,36 +916,24 @@ static __always_inline void exc_debug_user(struct pt_regs *regs,
/* IST stack entry */
DEFINE_IDTENTRY_DEBUG(exc_debug)
{
- unsigned long dr6, dr7;
-
- debug_enter(&dr6, &dr7);
- exc_debug_kernel(regs, dr6);
- debug_exit(dr7);
+ exc_debug_kernel(regs, debug_read_clear_dr6());
}
/* User entry, runs on regular task stack */
DEFINE_IDTENTRY_DEBUG_USER(exc_debug)
{
- unsigned long dr6, dr7;
-
- debug_enter(&dr6, &dr7);
- exc_debug_user(regs, dr6);
- debug_exit(dr7);
+ exc_debug_user(regs, debug_read_clear_dr6());
}
#else
/* 32 bit does not have separate entry points. */
DEFINE_IDTENTRY_RAW(exc_debug)
{
- unsigned long dr6, dr7;
-
- debug_enter(&dr6, &dr7);
+ unsigned long dr6 = debug_read_clear_dr6();
if (user_mode(regs))
exc_debug_user(regs, dr6);
else
exc_debug_kernel(regs, dr6);
-
- debug_exit(dr7);
}
#endif