diff mbox

[v4,1/4] x86/mm: Adapt MODULES_END based on Fixmap section size

Message ID 20170216215438.126111-1-thgarnie@google.com
State New, archived
Headers show

Commit Message

Thomas Garnier Feb. 16, 2017, 9:54 p.m. UTC
This patch aligns MODULES_END to the beginning of the Fixmap section.
It optimizes the space available for both sections. The address is
pre-computed based on the number of pages required by the Fixmap
section.

It will allow GDT remapping in the Fixmap section. The current
MODULES_END static address does not provide enough space for the kernel
to support a large number of processors.

Signed-off-by: Thomas Garnier <thgarnie@google.com>
---
Based on next-20170213
---
 Documentation/x86/x86_64/mm.txt         | 5 ++++-
 arch/x86/include/asm/pgtable_64_types.h | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

Comments

kernel test robot Feb. 17, 2017, 12:37 a.m. UTC | #1
Hi Thomas,

[auto build test ERROR on next-20170216]
[also build test ERROR on v4.10-rc8]
[cannot apply to tip/x86/core kvm/linux-next tip/auto-latest v4.9-rc8 v4.9-rc7 v4.9-rc6]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Thomas-Garnier/x86-mm-Adapt-MODULES_END-based-on-Fixmap-section-size/20170217-072759
config: x86_64-randconfig-h0-02170640 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

>> arch/x86/mm/dump_pagetables.c:87:2: error: implicit declaration of function '__fix_to_virt' [-Werror=implicit-function-declaration]
     { MODULES_END,          "End Modules" },
     ^
   In file included from arch/x86/include/asm/pgtable_types.h:240:0,
                    from arch/x86/include/asm/paravirt_types.h:44,
                    from arch/x86/include/asm/ptrace.h:71,
                    from arch/x86/include/asm/math_emu.h:4,
                    from arch/x86/include/asm/processor.h:11,
                    from arch/x86/include/asm/cpufeature.h:4,
                    from arch/x86/include/asm/thread_info.h:52,
                    from include/linux/thread_info.h:25,
                    from arch/x86/include/asm/preempt.h:6,
                    from include/linux/preempt.h:59,
                    from include/linux/spinlock.h:50,
                    from include/linux/wait.h:8,
                    from include/linux/fs.h:5,
                    from include/linux/debugfs.h:18,
                    from arch/x86/mm/dump_pagetables.c:15:
>> arch/x86/include/asm/pgtable_64_types.h:71:37: error: '__end_of_fixed_addresses' undeclared here (not in a function)
    #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
                                        ^
>> arch/x86/mm/dump_pagetables.c:87:4: note: in expansion of macro 'MODULES_END'
     { MODULES_END,          "End Modules" },
       ^
   cc1: some warnings being treated as errors

vim +/__fix_to_virt +87 arch/x86/mm/dump_pagetables.c

926e5392b Arjan van de Ven 2008-04-17   9   * This program is free software; you can redistribute it and/or
926e5392b Arjan van de Ven 2008-04-17  10   * modify it under the terms of the GNU General Public License
926e5392b Arjan van de Ven 2008-04-17  11   * as published by the Free Software Foundation; version 2
926e5392b Arjan van de Ven 2008-04-17  12   * of the License.
926e5392b Arjan van de Ven 2008-04-17  13   */
926e5392b Arjan van de Ven 2008-04-17  14  
fe770bf03 H. Peter Anvin   2008-04-17 @15  #include <linux/debugfs.h>
fe770bf03 H. Peter Anvin   2008-04-17  16  #include <linux/mm.h>
84e629b66 Paul Gortmaker   2016-07-13  17  #include <linux/init.h>
146fbb766 Andrey Ryabinin  2017-02-10  18  #include <linux/sched.h>
926e5392b Arjan van de Ven 2008-04-17  19  #include <linux/seq_file.h>
926e5392b Arjan van de Ven 2008-04-17  20  
926e5392b Arjan van de Ven 2008-04-17  21  #include <asm/pgtable.h>
926e5392b Arjan van de Ven 2008-04-17  22  
926e5392b Arjan van de Ven 2008-04-17  23  /*
926e5392b Arjan van de Ven 2008-04-17  24   * The dumper groups pagetable entries of the same type into one, and for
926e5392b Arjan van de Ven 2008-04-17  25   * that it needs to keep some state when walking, and flush this state
926e5392b Arjan van de Ven 2008-04-17  26   * when a "break" in the continuity is found.
926e5392b Arjan van de Ven 2008-04-17  27   */
926e5392b Arjan van de Ven 2008-04-17  28  struct pg_state {
926e5392b Arjan van de Ven 2008-04-17  29  	int level;
926e5392b Arjan van de Ven 2008-04-17  30  	pgprot_t current_prot;
926e5392b Arjan van de Ven 2008-04-17  31  	unsigned long start_address;
926e5392b Arjan van de Ven 2008-04-17  32  	unsigned long current_address;
fe770bf03 H. Peter Anvin   2008-04-17  33  	const struct addr_marker *marker;
3891a04aa H. Peter Anvin   2014-04-29  34  	unsigned long lines;
ef6bea6dd Borislav Petkov  2014-01-18  35  	bool to_dmesg;
e1a58320a Stephen Smalley  2015-10-05  36  	bool check_wx;
e1a58320a Stephen Smalley  2015-10-05  37  	unsigned long wx_pages;
926e5392b Arjan van de Ven 2008-04-17  38  };
926e5392b Arjan van de Ven 2008-04-17  39  
fe770bf03 H. Peter Anvin   2008-04-17  40  struct addr_marker {
fe770bf03 H. Peter Anvin   2008-04-17  41  	unsigned long start_address;
fe770bf03 H. Peter Anvin   2008-04-17  42  	const char *name;
3891a04aa H. Peter Anvin   2014-04-29  43  	unsigned long max_lines;
fe770bf03 H. Peter Anvin   2008-04-17  44  };
926e5392b Arjan van de Ven 2008-04-17  45  
92851e2fc Andres Salomon   2010-07-20  46  /* indices for address_markers; keep sync'd w/ address_markers below */
92851e2fc Andres Salomon   2010-07-20  47  enum address_markers_idx {
92851e2fc Andres Salomon   2010-07-20  48  	USER_SPACE_NR = 0,
92851e2fc Andres Salomon   2010-07-20  49  #ifdef CONFIG_X86_64
92851e2fc Andres Salomon   2010-07-20  50  	KERNEL_SPACE_NR,
92851e2fc Andres Salomon   2010-07-20  51  	LOW_KERNEL_NR,
92851e2fc Andres Salomon   2010-07-20  52  	VMALLOC_START_NR,
92851e2fc Andres Salomon   2010-07-20  53  	VMEMMAP_START_NR,
8a5a5d153 Mathias Krause   2014-09-07  54  # ifdef CONFIG_X86_ESPFIX64
3891a04aa H. Peter Anvin   2014-04-29  55  	ESPFIX_START_NR,
8a5a5d153 Mathias Krause   2014-09-07  56  # endif
92851e2fc Andres Salomon   2010-07-20  57  	HIGH_KERNEL_NR,
92851e2fc Andres Salomon   2010-07-20  58  	MODULES_VADDR_NR,
92851e2fc Andres Salomon   2010-07-20  59  	MODULES_END_NR,
92851e2fc Andres Salomon   2010-07-20  60  #else
92851e2fc Andres Salomon   2010-07-20  61  	KERNEL_SPACE_NR,
92851e2fc Andres Salomon   2010-07-20  62  	VMALLOC_START_NR,
92851e2fc Andres Salomon   2010-07-20  63  	VMALLOC_END_NR,
92851e2fc Andres Salomon   2010-07-20  64  # ifdef CONFIG_HIGHMEM
92851e2fc Andres Salomon   2010-07-20  65  	PKMAP_BASE_NR,
92851e2fc Andres Salomon   2010-07-20  66  # endif
92851e2fc Andres Salomon   2010-07-20  67  	FIXADDR_START_NR,
92851e2fc Andres Salomon   2010-07-20  68  #endif
92851e2fc Andres Salomon   2010-07-20  69  };
92851e2fc Andres Salomon   2010-07-20  70  
fe770bf03 H. Peter Anvin   2008-04-17  71  /* Address space markers hints */
fe770bf03 H. Peter Anvin   2008-04-17  72  static struct addr_marker address_markers[] = {
fe770bf03 H. Peter Anvin   2008-04-17  73  	{ 0, "User Space" },
fe770bf03 H. Peter Anvin   2008-04-17  74  #ifdef CONFIG_X86_64
fe770bf03 H. Peter Anvin   2008-04-17  75  	{ 0x8000000000000000UL, "Kernel Space" },
0483e1fa6 Thomas Garnier   2016-06-21  76  	{ 0/* PAGE_OFFSET */,   "Low Kernel Mapping" },
0483e1fa6 Thomas Garnier   2016-06-21  77  	{ 0/* VMALLOC_START */, "vmalloc() Area" },
0483e1fa6 Thomas Garnier   2016-06-21  78  	{ 0/* VMEMMAP_START */, "Vmemmap" },
8a5a5d153 Mathias Krause   2014-09-07  79  # ifdef CONFIG_X86_ESPFIX64
3891a04aa H. Peter Anvin   2014-04-29  80  	{ ESPFIX_BASE_ADDR,	"ESPfix Area", 16 },
8a5a5d153 Mathias Krause   2014-09-07  81  # endif
8266e31ed Mathias Krause   2014-09-21  82  # ifdef CONFIG_EFI
8266e31ed Mathias Krause   2014-09-21  83  	{ EFI_VA_END,		"EFI Runtime Services" },
8266e31ed Mathias Krause   2014-09-21  84  # endif
fe770bf03 H. Peter Anvin   2008-04-17  85  	{ __START_KERNEL_map,   "High Kernel Mapping" },
9a79cf9c1 Yinghai Lu       2008-03-07  86  	{ MODULES_VADDR,        "Modules" },
9a79cf9c1 Yinghai Lu       2008-03-07 @87  	{ MODULES_END,          "End Modules" },
fe770bf03 H. Peter Anvin   2008-04-17  88  #else
fe770bf03 H. Peter Anvin   2008-04-17  89  	{ PAGE_OFFSET,          "Kernel Mapping" },
fe770bf03 H. Peter Anvin   2008-04-17  90  	{ 0/* VMALLOC_START */, "vmalloc() Area" },

:::::: The code at line 87 was first introduced by commit
:::::: 9a79cf9c1aa671325fa5ba37576c2cee23823d04 x86: sort address_markers for dump_pagetables

:::::: TO: Yinghai Lu <yhlu.kernel@gmail.com>
:::::: CC: Ingo Molnar <mingo@elte.hu>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kernel test robot Feb. 17, 2017, 12:45 a.m. UTC | #2
Hi Thomas,

[auto build test ERROR on next-20170216]
[also build test ERROR on v4.10-rc8]
[cannot apply to tip/x86/core kvm/linux-next tip/auto-latest v4.9-rc8 v4.9-rc7 v4.9-rc6]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Thomas-Garnier/x86-mm-Adapt-MODULES_END-based-on-Fixmap-section-size/20170217-072759
config: x86_64-randconfig-s4-02170325 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   In file included from arch/x86/include/asm/pgtable_types.h:240:0,
                    from arch/x86/include/asm/paravirt_types.h:44,
                    from arch/x86/include/asm/ptrace.h:71,
                    from arch/x86/include/asm/math_emu.h:4,
                    from arch/x86/include/asm/processor.h:11,
                    from arch/x86/include/asm/cpufeature.h:4,
                    from arch/x86/include/asm/thread_info.h:52,
                    from include/linux/thread_info.h:25,
                    from arch/x86/include/asm/preempt.h:6,
                    from include/linux/preempt.h:59,
                    from include/linux/spinlock.h:50,
                    from include/linux/wait.h:8,
                    from include/linux/fs.h:5,
                    from include/linux/debugfs.h:18,
                    from arch/x86/mm/dump_pagetables.c:15:
>> arch/x86/include/asm/pgtable_64_types.h:71:23: error: implicit declaration of function '__fix_to_virt' [-Werror=implicit-function-declaration]
    #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
                          ^
   arch/x86/mm/dump_pagetables.c:87:4: note: in expansion of macro 'MODULES_END'
     { MODULES_END,          "End Modules" },
       ^~~~~~~~~~~
   arch/x86/include/asm/pgtable_64_types.h:71:37: error: '__end_of_fixed_addresses' undeclared here (not in a function)
    #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
                                        ^
   arch/x86/mm/dump_pagetables.c:87:4: note: in expansion of macro 'MODULES_END'
     { MODULES_END,          "End Modules" },
       ^~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/__fix_to_virt +71 arch/x86/include/asm/pgtable_64_types.h

    65	#define VMALLOC_START	__VMALLOC_BASE
    66	#define VMEMMAP_START	__VMEMMAP_BASE
    67	#endif /* CONFIG_RANDOMIZE_MEMORY */
    68	#define VMALLOC_END	(VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
    69	#define MODULES_VADDR    (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
    70	/* The module sections ends with the start of the fixmap */
  > 71	#define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
    72	#define MODULES_LEN   (MODULES_END - MODULES_VADDR)
    73	#define ESPFIX_PGD_ENTRY _AC(-2, UL)
    74	#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Thomas Garnier Feb. 17, 2017, 4 p.m. UTC | #3
I will send an update patch on this thread to fix the fixmap dependencies.

On Thu, Feb 16, 2017 at 4:45 PM, kbuild test robot <lkp@intel.com> wrote:

> Hi Thomas,
>
> [auto build test ERROR on next-20170216]
> [also build test ERROR on v4.10-rc8]
> [cannot apply to tip/x86/core kvm/linux-next tip/auto-latest v4.9-rc8
> v4.9-rc7 v4.9-rc6]
> [if your patch is applied to the wrong git tree, please drop us a note to
> help improve the system]
>
> url:    https://github.com/0day-ci/linux/commits/Thomas-Garnier/
> x86-mm-Adapt-MODULES_END-based-on-Fixmap-section-size/20170217-072759
> config: x86_64-randconfig-s4-02170325 (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=x86_64
>
> All errors (new ones prefixed by >>):
>
>    In file included from arch/x86/include/asm/pgtable_types.h:240:0,
>                     from arch/x86/include/asm/paravirt_types.h:44,
>                     from arch/x86/include/asm/ptrace.h:71,
>                     from arch/x86/include/asm/math_emu.h:4,
>                     from arch/x86/include/asm/processor.h:11,
>                     from arch/x86/include/asm/cpufeature.h:4,
>                     from arch/x86/include/asm/thread_info.h:52,
>                     from include/linux/thread_info.h:25,
>                     from arch/x86/include/asm/preempt.h:6,
>                     from include/linux/preempt.h:59,
>                     from include/linux/spinlock.h:50,
>                     from include/linux/wait.h:8,
>                     from include/linux/fs.h:5,
>                     from include/linux/debugfs.h:18,
>                     from arch/x86/mm/dump_pagetables.c:15:
> >> arch/x86/include/asm/pgtable_64_types.h:71:23: error: implicit
> declaration of function '__fix_to_virt' [-Werror=implicit-function-
> declaration]
>     #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
>                           ^
>    arch/x86/mm/dump_pagetables.c:87:4: note: in expansion of macro
> 'MODULES_END'
>      { MODULES_END,          "End Modules" },
>        ^~~~~~~~~~~
>    arch/x86/include/asm/pgtable_64_types.h:71:37: error:
> '__end_of_fixed_addresses' undeclared here (not in a function)
>     #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
>                                         ^
>    arch/x86/mm/dump_pagetables.c:87:4: note: in expansion of macro
> 'MODULES_END'
>      { MODULES_END,          "End Modules" },
>        ^~~~~~~~~~~
>    cc1: some warnings being treated as errors
>
> vim +/__fix_to_virt +71 arch/x86/include/asm/pgtable_64_types.h
>
>     65  #define VMALLOC_START   __VMALLOC_BASE
>     66  #define VMEMMAP_START   __VMEMMAP_BASE
>     67  #endif /* CONFIG_RANDOMIZE_MEMORY */
>     68  #define VMALLOC_END     (VMALLOC_START + _AC((VMALLOC_SIZE_TB <<
> 40) - 1, UL))
>     69  #define MODULES_VADDR    (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
>     70  /* The module sections ends with the start of the fixmap */
>   > 71  #define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
>     72  #define MODULES_LEN   (MODULES_END - MODULES_VADDR)
>     73  #define ESPFIX_PGD_ENTRY _AC(-2, UL)
>     74  #define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology
> Center
> https://lists.01.org/pipermail/kbuild-all                   Intel
> Corporation
>
diff mbox

Patch

diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 5724092db811..ee3f9c30957c 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -19,7 +19,7 @@  ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
 ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
 ... unused hole ...
 ffffffff80000000 - ffffffff9fffffff (=512 MB)  kernel text mapping, from phys 0
-ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space
+ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space (variable)
 ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
 ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
 
@@ -39,6 +39,9 @@  memory window (this size is arbitrary, it can be raised later if needed).
 The mappings are not part of any other kernel PGD and are only available
 during EFI runtime calls.
 
+The module mapping space size changes based on the CONFIG requirements for the
+following fixmap section.
+
 Note that if CONFIG_RANDOMIZE_MEMORY is enabled, the direct mapping of all
 physical memory, vmalloc/ioremap space and virtual memory map are randomized.
 Their order is preserved but their base will be offset early at boot time.
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index 3a264200c62f..bb05e21cf3c7 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -67,7 +67,8 @@  typedef struct { pteval_t pte; } pte_t;
 #endif /* CONFIG_RANDOMIZE_MEMORY */
 #define VMALLOC_END	(VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
 #define MODULES_VADDR    (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
-#define MODULES_END      _AC(0xffffffffff000000, UL)
+/* The module sections ends with the start of the fixmap */
+#define MODULES_END   __fix_to_virt(__end_of_fixed_addresses + 1)
 #define MODULES_LEN   (MODULES_END - MODULES_VADDR)
 #define ESPFIX_PGD_ENTRY _AC(-2, UL)
 #define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)