This array is [MAX_LOCAL_APIC], and MAX_LOCAL_APIC can easily be up to 32k.
This patch changes apic_version[] array elements from int to u8 -
APIC version values as of year 2016 are no larger than 0x1f on all known CPUs.
Version field in the APIC register is 8 bit wide - not likely
to overflow byte range in foreseeable future.
The "ver" argument of generic_processor_info(id,ver), which goes into
apic_version[id],
is also changed from int to u8: make it obvious that assignment can't overflow.
generic_processor_info() has four callsites, none of them can put an
out-of-range value
into this argument.
Signed-off-by: Denys Vlasenko <dvlas...@redhat.com>
CC: Ingo Molnar <mi...@kernel.org>
CC: Andy Lutomirski <l...@amacapital.net>
CC: "H. Peter Anvin" <h...@zytor.com>
CC: Borislav Petkov <b...@alien8.de>
CC: Brian Gerst <brge...@gmail.com>
CC: x...@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/include/asm/mpspec.h | 4 ++--
arch/x86/kernel/acpi/boot.c | 2 +-
arch/x86/kernel/apic/apic.c | 4 ++--
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index b07233b..a0bc349 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -6,7 +6,7 @@
#include <asm/x86_init.h>
#include <asm/apicdef.h>
-extern int apic_version[];
+extern u8 apic_version[];
extern int pic_mode;
#ifdef CONFIG_X86_32
@@ -85,7 +85,7 @@ static inline void early_reserve_e820_mpc_new(void) { }
#define default_get_smp_config x86_init_uint_noop
#endif
-int generic_processor_info(int apicid, int version);
+int generic_processor_info(int apicid, u8 version);
#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 90d84c3..fde236f 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -168,7 +168,7 @@ static int __init acpi_parse_madt(struct acpi_table_header
*table)
*/
static int acpi_register_lapic(int id, u32 acpiid, u8 enabled)
{
- unsigned int ver = 0;
+ u8 ver = 0;
int cpu;
if (id >= MAX_LOCAL_APIC) {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 50c95af..d5cc7c6 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1837,7 +1837,7 @@ void __init register_lapic_address(unsigned long address)
}
}
-int apic_version[MAX_LOCAL_APIC];
+u8 apic_version[MAX_LOCAL_APIC];
/*
* Local APIC interrupts
@@ -2027,7 +2027,7 @@ void disconnect_bsp_APIC(int virt_wire_setup)
apic_write(APIC_LVT1, value);
}
-int generic_processor_info(int apicid, int version)
+int generic_processor_info(int apicid, u8 version)
{
int cpu, max = nr_cpu_ids;
bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
--
2.9.2
