[tip:x86/urgent] x86/apic: Fix signedness bug in APIC ID validity checks
From: tip-bot for Li RongQing
Date: Tue Apr 10 2018 - 10:41:29 EST
Commit-ID: 57e95bee9f89560c5952409be8b41a4a2b7e384c
Gitweb: https://git.kernel.org/tip/57e95bee9f89560c5952409be8b41a4a2b7e384c
Author: Li RongQing <lirongqing@xxxxxxxxx>
AuthorDate: Tue, 10 Apr 2018 09:16:06 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 10 Apr 2018 16:33:21 +0200
x86/apic: Fix signedness bug in APIC ID validity checks
The APIC ID as parsed from ACPI MADT is validity checked with the
apic->apic_id_valid() callback, which depends on the selected APIC type.
For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFFFFFF
are detected as valid. This happens because the 'apicid' argument of the
apic_id_valid() callback is type 'int'. So the resulting comparison
apicid < 0xFF
evaluates to true for all unsigned int values > 0x7FFFFFFF which are handed
to default_apic_id_valid(). As a consequence, invalid APIC IDs in !X2APIC
mode are considered valid and accounted as possible CPUs.
Change the apicid argument type of the apic_id_valid() callback to u32 so
the evaluation is unsigned and returns the correct result.
[ tglx: Massaged changelog ]
Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: jgross@xxxxxxxx
Cc: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: hpa@xxxxxxxxx
Link: https://lkml.kernel.org/r/1523322966-10296-1-git-send-email-lirongqing@xxxxxxxxx
---
arch/x86/include/asm/apic.h | 4 ++--
arch/x86/kernel/acpi/boot.c | 13 ++++++++-----
arch/x86/kernel/apic/apic_common.c | 2 +-
arch/x86/kernel/apic/apic_numachip.c | 2 +-
arch/x86/kernel/apic/x2apic.h | 2 +-
arch/x86/kernel/apic/x2apic_phys.c | 2 +-
arch/x86/kernel/apic/x2apic_uv_x.c | 2 +-
arch/x86/xen/apic.c | 2 +-
8 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 98722773391d..f01eef8b392e 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -319,7 +319,7 @@ struct apic {
/* Probe, setup and smpboot functions */
int (*probe)(void);
int (*acpi_madt_oem_check)(char *oem_id, char *oem_table_id);
- int (*apic_id_valid)(int apicid);
+ int (*apic_id_valid)(u32 apicid);
int (*apic_id_registered)(void);
bool (*check_apicid_used)(physid_mask_t *map, int apicid);
@@ -492,7 +492,7 @@ static inline unsigned int read_apic_id(void)
return apic->get_apic_id(reg);
}
-extern int default_apic_id_valid(int apicid);
+extern int default_apic_id_valid(u32 apicid);
extern int default_acpi_madt_oem_check(char *, char *);
extern void default_setup_apic_routing(void);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 2aa92094b59d..cc7ddc932cf2 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -200,7 +200,7 @@ acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
{
struct acpi_madt_local_x2apic *processor = NULL;
#ifdef CONFIG_X86_X2APIC
- int apic_id;
+ u32 apic_id;
u8 enabled;
#endif
@@ -222,10 +222,13 @@ acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
* to not preallocating memory for all NR_CPUS
* when we use CPU hotplug.
*/
- if (!apic->apic_id_valid(apic_id) && enabled)
- printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
- else
- acpi_register_lapic(apic_id, processor->uid, enabled);
+ if (!apic->apic_id_valid(apic_id)) {
+ if (enabled)
+ printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
+ return 0;
+ }
+
+ acpi_register_lapic(apic_id, processor->uid, enabled);
#else
printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
#endif
diff --git a/arch/x86/kernel/apic/apic_common.c b/arch/x86/kernel/apic/apic_common.c
index a360801779ae..02b4839478b1 100644
--- a/arch/x86/kernel/apic/apic_common.c
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -40,7 +40,7 @@ int default_check_phys_apicid_present(int phys_apicid)
return physid_isset(phys_apicid, phys_cpu_present_map);
}
-int default_apic_id_valid(int apicid)
+int default_apic_id_valid(u32 apicid)
{
return (apicid < 255);
}
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 134e04506ab4..78778b54f904 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -56,7 +56,7 @@ static u32 numachip2_set_apic_id(unsigned int id)
return id << 24;
}
-static int numachip_apic_id_valid(int apicid)
+static int numachip_apic_id_valid(u32 apicid)
{
/* Trust what bootloader passes in MADT */
return 1;
diff --git a/arch/x86/kernel/apic/x2apic.h b/arch/x86/kernel/apic/x2apic.h
index b107de381cb5..a49b3604027f 100644
--- a/arch/x86/kernel/apic/x2apic.h
+++ b/arch/x86/kernel/apic/x2apic.h
@@ -1,6 +1,6 @@
/* Common bits for X2APIC cluster/physical modes. */
-int x2apic_apic_id_valid(int apicid);
+int x2apic_apic_id_valid(u32 apicid);
int x2apic_apic_id_registered(void);
void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest);
unsigned int x2apic_get_apic_id(unsigned long id);
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index f8d9d69994e6..e972405eb2b5 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -101,7 +101,7 @@ static int x2apic_phys_probe(void)
}
/* Common x2apic functions, also used by x2apic_cluster */
-int x2apic_apic_id_valid(int apicid)
+int x2apic_apic_id_valid(u32 apicid)
{
return 1;
}
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index f11910b44638..efaf2d4f9c3c 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -557,7 +557,7 @@ static void uv_send_IPI_all(int vector)
uv_send_IPI_mask(cpu_online_mask, vector);
}
-static int uv_apic_id_valid(int apicid)
+static int uv_apic_id_valid(u32 apicid)
{
return 1;
}
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index de58533d3664..2fa79e2e73ea 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -112,7 +112,7 @@ static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
return xen_pv_domain();
}
-static int xen_id_always_valid(int apicid)
+static int xen_id_always_valid(u32 apicid)
{
return 1;
}