Commit-ID: a774635db5c430cbf21fa5d2f2df3d23aaa8e782 Gitweb: https://git.kernel.org/tip/a774635db5c430cbf21fa5d2f2df3d23aaa8e782 Author: Li RongQing <lirongq...@baidu.com> AuthorDate: Tue, 10 Apr 2018 09:16:06 +0800 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Tue, 10 Apr 2018 16:46:39 +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 <lirongq...@baidu.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: sta...@vger.kernel.org Cc: jgr...@suse.com Cc: Dou Liyang <douly.f...@cn.fujitsu.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: h...@zytor.com Link: https://lkml.kernel.org/r/1523322966-10296-1-git-send-email-lirongq...@baidu.com --- 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..5ee33a6e33bb 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) + pr_warn(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; }
