From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755597AbdERU2h (ORCPT ); Thu, 18 May 2017 16:28:37 -0400 Received: from g2t1383g.austin.hpe.com ([15.233.16.89]:18171 "EHLO g2t1383g.austin.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752218AbdERU2f (ORCPT ); Thu, 18 May 2017 16:28:35 -0400 Authentication-Results: hpe.com; dkim=none (message not signed) header.d=none;hpe.com; dmarc=none action=none header.from=hpe.com; Subject: Re: [PATCH] x86/mm/KASLR: Do not adapt the size of the direct mapping section for SGI UV system To: Baoquan He , References: <1495090323-21679-1-git-send-email-bhe@redhat.com> <435f6dd1-8589-bf44-fb81-f2e3943fd3df@hpe.com> CC: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , , Matt Fleming , Ard Biesheuvel , "travis@sgi.com" , Dimitri Sivanich , Thomas Garnier , Kees Cook , Andrew Morton , Masahiro Yamada , Russ Anderson , Frank Ramsay From: Mike Travis Message-ID: Date: Thu, 18 May 2017 13:28:18 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <435f6dd1-8589-bf44-fb81-f2e3943fd3df@hpe.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [73.222.225.80] X-ClientProxiedBy: BN6PR11CA0020.namprd11.prod.outlook.com (2603:10b6:405:2::30) To AT5PR84MB0226.NAMPRD84.PROD.OUTLOOK.COM (2a01:111:e400:7405::23) X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: AT5PR84MB0226: X-MS-Office365-Filtering-Correlation-Id: 96f5376e-b5f7-45a4-aef7-08d49e2c71fa X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(48565401081)(201703131423075)(201703031133081);SRVR:AT5PR84MB0226; X-Microsoft-Exchange-Diagnostics: 1;AT5PR84MB0226;3:MHNOZLaSRG9N6tCOvkQSv8/fOexnUB0RtRmmzTHo5RKAFy4360jegLF6LvO9B9muf8J0EiW8Kt2bSf/DamnirXI8AlLBj7oNYMHNF6Vp8vDfsEQPnAJV1sfDuU3WykWFEwEYJMCNMth4LshWMjj6v5Gef8O+qAKtWjJVkix6RL84QhuU4xtn0D7z6Yd84gtY7ETmkmx6Fo9zanXQV3eFcK7jJ944FhbJVhareHAd6K6IcT1sV4XnauZkqvcAIaWLhpwPh5lWT5BOIxt2vqexdVHb2ZMxCjb5gFIsyqbHE/oRec9yDgM/scUuLVvHsJziOzloqytvnNghCYQhjFI7Z21LkCU0z4sq6Og2vxF/aJc=;25:BhGql+eeGnAghHtv8m1I4gfYeEs4d/qRBm/oC4NtjPJDUENCpyu7HudapmX0X9ajpgqdS0uVj12ht7rgOpqjgC16BPL3U7hFTBLDxJbqXzlLFpJP2KdPEgOOkukhWMQVvdTGvAQRaOxRD/cAnlczWDHV+ePyRTKLe00XqrruiBxxceU5RGW4gJca/ZL0zir/hboGuz5+3il2DG9+53s0BIWW+k5532q6vYdDSNfh3URCW02xBTwj4Goihy7Q7pZ3U43wPmntbdYKQzy/qiSzsqDy2tJuYA1pceQv6h8tUGRRTeR/DE5mG3rPt0Rgn5hlBdBM90DYkdRTi5XOSYPF4Kp1sxRyAxRWCo2lrad74JM/PCGeb31uUWrheBvsqJKdf1hZxzAReApOF/RAXBVWnZiteM/VAp9g5xL9KPzYOLfX7VH/HD+SXoh4MhVGri3zhxLNKnrlpAmGBDHy3+FjSMb5AQaTVQhclcT87UCZOKo= X-Microsoft-Exchange-Diagnostics: 1;AT5PR84MB0226;31:EM84u9NXfkJrwJ7DRS+cZ0QUcojrs35qMtWiTXOqhuDB9gzAuCVdY2lfS1oCguMiJtAxpSi4C/mlYDQqMlRSiX8qjKhYitZjnsFy8NWan0JlPc5aHzPNaF9u/bFO+vl2LnQXHrLv6ODxehbE/l90Gzp54xDf+BKG7k3qiwCDeIHybPuiqTVK4QOk2Hf/Bk8rhGgpEDtlxqykVfxxtqiHFBtVqyFmpQghrm87D/3WS5o=;20: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 X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(227479698468861)(9452136761055)(211936372134217); 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Thanks. On 5/18/2017 1:26 PM, Mike Travis wrote: > Hi Baoquan He, > > The concept of the patch is correct (since it is I as sent :), > but I would prefer that the entire is_early_uv_system() be put > into the uv.h file. Primarily because we may need to change > that in the future so having UV specific code in other places > than under platform/uv is not that desirable. Plus I think it's > better to consolidate the logic in one place. > > Making it an inline function in uv.h is fine for now. If we > need to change it, I'll move it to the UV specific init > function. > > And if it's alright with others, you should add the #include > of the efi.h header file under the part of uv.h that has > #ifdef CONFIG_X86_UV defined. > > That would mean the KASLR function would only add an > #include to access that UV specific funtion. > > Thanks, > Mike > > On 5/17/2017 11:52 PM, Baoquan He wrote: >> On SGI UV system, kernel casually hang with kaslr enabled. >> >> The back trace is: >> >> kernel BUG at arch/x86/mm/init_64.c:311! >> invalid opcode: 0000 [#1] SMP >> [...] >> RIP: 0010:__init_extra_mapping+0x188/0x196 >> [...] >> Call Trace: >> init_extra_mapping_uc+0x13/0x15 >> map_high+0x67/0x75 >> map_mmioh_high_uv3+0x20a/0x219 >> uv_system_init_hub+0x12d9/0x1496 >> uv_system_init+0x27/0x29 >> native_smp_prepare_cpus+0x28d/0x2d8 >> kernel_init_freeable+0xdd/0x253 >> ? rest_init+0x80/0x80 >> kernel_init+0xe/0x110 >> ret_from_fork+0x2c/0x40 >> >> The root cause is SGI UV system needs map its MMIOH region to direct >> mapping section. >> >> When kaslr disabled, there are 64TB space for system RAM to do direct >> mapping. Both system RAM and SGI UV MMIOH region share this 64TB space. >> However with kaslr enabled, mm KASLR only reserves the actual size of >> system RAM plus 10TB for direct mapping usage. Then MMIOH mapping of >> SGI UV could go beyond the upper bound of direct mapping section to step >> into VMALLOC or VMEMMAP area. Then the BUG_ON() in __init_extra_mapping() >> will be triggered. >> >> E.g on the SGI UV3 machine where this bug is reported , there are two MMIOH >> regions: >> >> [ 1.519001] UV: Map MMIOH0_HI 0xffc00000000 - 0x100000000000 >> [ 1.523001] UV: Map MMIOH1_HI 0x100000000000 - 0x200000000000 >> >> They are [16TB-16G, 16TB) and [16TB, 32TB). On this machine, 512G ram are >> spread out to 1TB regions. Then above two SGI MMIOH regions also will be >> mapped into the direct mapping section. The point is that SGI UV maps its >> MMIOH regions to the direct mapping section in uv_system_init() which is >> called during kernel_init_freeable(). It's much later than >> kernel_randomize_memory(). Mm KASLR has no chance to take it into >> consideration. >> >> To fix it, we need detect if it's SGI UV system early, then do not adapt >> the size of the direct mapping section in kernel_randomize_memory() if yes. >> According to discussion with SGI developer, "The SGI bios adds UVsystab. >> Only systems running SGI bios (and now HPE Hawks2) will have UVsystab." >> >> Hence check if UVsystab is present, if yes, do not adapt the size of the >> direct mapping section in kernel_randomize_memory() >> >> Signed-off-by: Baoquan He >> Cc: Thomas Gleixner >> Cc: Ingo Molnar >> Cc: "H. Peter Anvin" >> Cc: x86@kernel.org >> Cc: Matt Fleming >> Cc: Ard Biesheuvel >> Cc: "travis@sgi.com" >> Cc: Dimitri Sivanich >> Cc: Thomas Garnier >> Cc: Kees Cook >> Cc: Andrew Morton >> Cc: Masahiro Yamada >> Cc: Russ Anderson >> Cc: Frank Ramsay >> linux-efi@vger.kernel.org >> --- >> arch/x86/include/asm/uv/uv.h | 2 ++ >> arch/x86/mm/kaslr.c | 4 +++- >> arch/x86/platform/efi/efi.c | 7 +++++++ >> 3 files changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h >> index 6686820..0275776 100644 >> --- a/arch/x86/include/asm/uv/uv.h >> +++ b/arch/x86/include/asm/uv/uv.h >> @@ -11,6 +11,7 @@ struct mm_struct; >> extern enum uv_system_type get_uv_system_type(void); >> extern int is_uv_system(void); >> extern int is_uv_hubless(void); >> +extern int is_early_uv_system(void); >> extern void uv_cpu_init(void); >> extern void uv_nmi_init(void); >> extern void uv_system_init(void); >> @@ -25,6 +26,7 @@ extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask, >> static inline enum uv_system_type get_uv_system_type(void) { return UV_NONE; } >> static inline int is_uv_system(void) { return 0; } >> static inline int is_uv_hubless(void) { return 0; } >> +static inline int is_early_uv_system(void) { return 0; } >> static inline void uv_cpu_init(void) { } >> static inline void uv_system_init(void) { } >> static inline const struct cpumask * >> diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c >> index aed2064..b75e1f5 100644 >> --- a/arch/x86/mm/kaslr.c >> +++ b/arch/x86/mm/kaslr.c >> @@ -22,11 +22,13 @@ >> #include >> #include >> #include >> +#include >> >> #include >> #include >> #include >> #include >> +#include >> >> #include "mm_internal.h" >> >> @@ -123,7 +125,7 @@ void __init kernel_randomize_memory(void) >> CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING; >> >> /* Adapt phyiscal memory region size based on available memory */ >> - if (memory_tb < kaslr_regions[0].size_tb) >> + if (memory_tb < kaslr_regions[0].size_tb && !is_early_uv_system()) >> kaslr_regions[0].size_tb = memory_tb; >> >> /* Calculate entropy available between regions */ >> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c >> index 7e76a4d..b71e01d 100644 >> --- a/arch/x86/platform/efi/efi.c >> +++ b/arch/x86/platform/efi/efi.c >> @@ -74,6 +74,13 @@ static int __init setup_add_efi_memmap(char *arg) >> } >> early_param("add_efi_memmap", setup_add_efi_memmap); >> >> +#ifdef CONFIG_X86_UV >> +int is_early_uv_system(void) >> +{ >> + return !((efi.uv_systab == EFI_INVALID_TABLE_ADDR) || !efi.uv_systab); >> +} >> +#endif >> + >> static efi_status_t __init phys_efi_set_virtual_address_map( >> unsigned long memory_map_size, >> unsigned long descriptor_size, >>