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Message-Id: <20191007123819.161432-2-ralf.ramsauer@oth-regensburg.de>
Date: Mon, 7 Oct 2019 14:38:18 +0200
From: Ralf Ramsauer <ralf.ramsauer@...-regensburg.de>
To: Jan Kiszka <jan.kiszka@...mens.com>,
Borislav Petkov <bp@...en8.de>, x86@...nel.org,
jailhouse-dev@...glegroups.com, linux-kernel@...r.kernel.org
Cc: Ingo Molnar <mingo@...hat.com>, "H . Peter Anvin" <hpa@...or.com>,
Ralf Ramsauer <ralf.ramsauer@...-regensburg.de>
Subject: [PATCH v5 1/2] x86/jailhouse: improve setup data version comparison
We will soon introduce a new setup_data version and extend the
structure. This requires some preparational work for the sanity check of
the header and the check of the version.
Use the following strategy:
1. Ensure that the header declares at least enough space for the version
and the compatible_version as we must hold that fields for any
version. Furthermore, the location and semantics of those fields will
never change.
2. Copy over data -- as much as we can. The length is either limited by
the header length, or the length of setup_data.
3. Things are now in place -- sanity check if the header length complies
the actual version.
For future versions of the setup_data, only step 3 requires alignment.
Signed-off-by: Ralf Ramsauer <ralf.ramsauer@...-regensburg.de>
Reviewed-by: Jan Kiszka <jan.kiszka@...mens.com>
---
arch/x86/include/uapi/asm/bootparam.h | 22 +++++++-----
arch/x86/kernel/jailhouse.c | 50 +++++++++++++++++----------
2 files changed, 44 insertions(+), 28 deletions(-)
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index c895df5482c5..43be437c9c71 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -139,15 +139,19 @@ struct boot_e820_entry {
* setup data structure.
*/
struct jailhouse_setup_data {
- __u16 version;
- __u16 compatible_version;
- __u16 pm_timer_address;
- __u16 num_cpus;
- __u64 pci_mmconfig_base;
- __u32 tsc_khz;
- __u32 apic_khz;
- __u8 standard_ioapic;
- __u8 cpu_ids[255];
+ struct {
+ __u16 version;
+ __u16 compatible_version;
+ } __attribute__((packed)) hdr;
+ struct {
+ __u16 pm_timer_address;
+ __u16 num_cpus;
+ __u64 pci_mmconfig_base;
+ __u32 tsc_khz;
+ __u32 apic_khz;
+ __u8 standard_ioapic;
+ __u8 cpu_ids[255];
+ } __attribute__((packed)) v1;
} __attribute__((packed));
/* The so-called "zeropage" */
diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index 3ad34f01de2a..b9647add0063 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -22,6 +22,8 @@
#include <asm/jailhouse_para.h>
static __initdata struct jailhouse_setup_data setup_data;
+#define SETUP_DATA_V1_LEN (sizeof(setup_data.hdr) + sizeof(setup_data.v1))
+
static unsigned int precalibrated_tsc_khz;
static uint32_t jailhouse_cpuid_base(void)
@@ -45,7 +47,7 @@ static void jailhouse_get_wallclock(struct timespec64 *now)
static void __init jailhouse_timer_init(void)
{
- lapic_timer_period = setup_data.apic_khz * (1000 / HZ);
+ lapic_timer_period = setup_data.v1.apic_khz * (1000 / HZ);
}
static unsigned long jailhouse_get_tsc(void)
@@ -88,14 +90,14 @@ static void __init jailhouse_get_smp_config(unsigned int early)
register_lapic_address(0xfee00000);
- for (cpu = 0; cpu < setup_data.num_cpus; cpu++) {
- generic_processor_info(setup_data.cpu_ids[cpu],
+ for (cpu = 0; cpu < setup_data.v1.num_cpus; cpu++) {
+ generic_processor_info(setup_data.v1.cpu_ids[cpu],
boot_cpu_apic_version);
}
smp_found_config = 1;
- if (setup_data.standard_ioapic) {
+ if (setup_data.v1.standard_ioapic) {
mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
@@ -126,9 +128,9 @@ static int __init jailhouse_pci_arch_init(void)
pcibios_last_bus = 0xff;
#ifdef CONFIG_PCI_MMCONFIG
- if (setup_data.pci_mmconfig_base) {
+ if (setup_data.v1.pci_mmconfig_base) {
pci_mmconfig_add(0, 0, pcibios_last_bus,
- setup_data.pci_mmconfig_base);
+ setup_data.v1.pci_mmconfig_base);
pci_mmcfg_arch_init();
}
#endif
@@ -139,6 +141,7 @@ static int __init jailhouse_pci_arch_init(void)
static void __init jailhouse_init_platform(void)
{
u64 pa_data = boot_params.hdr.setup_data;
+ unsigned long setup_data_len;
struct setup_data header;
void *mapping;
@@ -163,16 +166,8 @@ static void __init jailhouse_init_platform(void)
memcpy(&header, mapping, sizeof(header));
early_memunmap(mapping, sizeof(header));
- if (header.type == SETUP_JAILHOUSE &&
- header.len >= sizeof(setup_data)) {
- pa_data += offsetof(struct setup_data, data);
-
- mapping = early_memremap(pa_data, sizeof(setup_data));
- memcpy(&setup_data, mapping, sizeof(setup_data));
- early_memunmap(mapping, sizeof(setup_data));
-
+ if (header.type == SETUP_JAILHOUSE)
break;
- }
pa_data = header.next;
}
@@ -180,13 +175,26 @@ static void __init jailhouse_init_platform(void)
if (!pa_data)
panic("Jailhouse: No valid setup data found");
- if (setup_data.compatible_version > JAILHOUSE_SETUP_REQUIRED_VERSION)
- panic("Jailhouse: Unsupported setup data structure");
+ /* setup data must at least contain the header */
+ if (header.len < sizeof(setup_data.hdr))
+ goto unsupported;
- pmtmr_ioport = setup_data.pm_timer_address;
+ pa_data += offsetof(struct setup_data, data);
+ setup_data_len = min(sizeof(setup_data), (unsigned long)header.len);
+ mapping = early_memremap(pa_data, setup_data_len);
+ memcpy(&setup_data, mapping, setup_data_len);
+ early_memunmap(mapping, setup_data_len);
+
+ if (setup_data.hdr.version == 0 ||
+ setup_data.hdr.compatible_version !=
+ JAILHOUSE_SETUP_REQUIRED_VERSION ||
+ (setup_data.hdr.version >= 1 && header.len < SETUP_DATA_V1_LEN))
+ goto unsupported;
+
+ pmtmr_ioport = setup_data.v1.pm_timer_address;
pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
- precalibrated_tsc_khz = setup_data.tsc_khz;
+ precalibrated_tsc_khz = setup_data.v1.tsc_khz;
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
pci_probe = 0;
@@ -196,6 +204,10 @@ static void __init jailhouse_init_platform(void)
* are none in a non-root cell.
*/
disable_acpi();
+ return;
+
+unsupported:
+ panic("Jailhouse: Unsupported setup data structure");
}
bool jailhouse_paravirt(void)
--
2.23.0
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