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| author |   Vlastimil Babka <vbabka@suse.cz> | 2018-08-20 11:58:35 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-08-20 18:04:42 +0200 |
| commit | 9df9516940a61d29aedf4d91b483ca6597e7d480 (patch) | |
| tree | 446dddbc72dc1059d59be9c4e49f1d6745db1537 /arch/x86/include | |
| parent | x86/process: Re-export start_thread() (diff) | |
| download | wireguard-linux-9df9516940a61d29aedf4d91b483ca6597e7d480.tar.xz wireguard-linux-9df9516940a61d29aedf4d91b483ca6597e7d480.zip | |
x86/speculation/l1tf: Fix overflow in l1tf_pfn_limit() on 32bit
On 32bit PAE kernels on 64bit hardware with enough physical bits,
l1tf_pfn_limit() will overflow unsigned long. This in turn affects
max_swapfile_size() and can lead to swapon returning -EINVAL. This has been
observed in a 32bit guest with 42 bits physical address size, where
max_swapfile_size() overflows exactly to 1 << 32, thus zero, and produces
the following warning to dmesg:
[ 6.396845] Truncating oversized swap area, only using 0k out of 2047996k
Fix this by using unsigned long long instead.
Fixes: 17dbca119312 ("x86/speculation/l1tf: Add sysfs reporting for l1tf")
Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Reported-by: Dominique Leuenberger <dimstar@suse.de>
Reported-by: Adrian Schroeter <adrian@suse.de>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180820095835.5298-1-vbabka@suse.cz
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 682286aca881..a0a52274cb4a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -181,9 +181,9 @@ extern const struct seq_operations cpuinfo_op; extern void cpu_detect(struct cpuinfo_x86 *c); -static inline unsigned long l1tf_pfn_limit(void) +static inline unsigned long long l1tf_pfn_limit(void) { - return BIT(boot_cpu_data.x86_phys_bits - 1 - PAGE_SHIFT) - 1; + return BIT_ULL(boot_cpu_data.x86_phys_bits - 1 - PAGE_SHIFT) - 1; } extern void early_cpu_init(void); |