* [linux-next:master 5970/6564] mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores]
@ 2022-02-22 1:23 kernel test robot
2022-02-22 9:05 ` kernel test robot
0 siblings, 1 reply; 2+ messages in thread
From: kernel test robot @ 2022-02-22 1:23 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 19630 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: Linux Memory Management List <linux-mm@kvack.org>
TO: Hugh Dickins <hughd@google.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linux Memory Management List <linux-mm@kvack.org>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: 3c30cf91b5ecc7272b3d2942ae0505dd8320b81c
commit: c1879365d325d0f44337fedcfffe8bf200092f95 [5970/6564] mm/munlock: rmap call mlock_vma_page() munlock_vma_page()
:::::: branch date: 5 days ago
:::::: commit date: 6 days ago
config: x86_64-randconfig-c007-20220221 (https://download.01.org/0day-ci/archive/20220222/202202220917.CFUvfxmY-lkp(a)intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c1879365d325d0f44337fedcfffe8bf200092f95
git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout c1879365d325d0f44337fedcfffe8bf200092f95
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
^~~
drivers/base/bus.c:53:2: note: Taking true branch
if (bus)
^
drivers/base/bus.c:55:1: note: Returning without writing to 'bus->p'
}
^
drivers/base/bus.c:147:3: note: Returning from 'bus_put'
bus_put(bus);
^~~~~~~~~~~~
drivers/base/bus.c:149:1: note: Returning without writing to '->p'
}
^
drivers/base/bus.c:573:2: note: Returning from 'bus_remove_file'
bus_remove_file(bus, &bus_attr_drivers_probe);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/base/bus.c:574:1: note: Returning without writing to 'bus->p'
}
^
drivers/base/bus.c:872:2: note: Returning from 'remove_probe_files'
remove_probe_files(bus);
^~~~~~~~~~~~~~~~~~~~~~~
drivers/base/bus.c:873:18: note: Access to field 'drivers_kset' results in a dereference of a null pointer (loaded from field 'p')
kset_unregister(bus->p->drivers_kset);
^ ~
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
drivers/char/tpm/eventlog/tpm1.c:276:2: warning: Value stored to 'len' is never read [clang-analyzer-deadcode.DeadStores]
len += get_event_name(eventname, event, event_entry);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/char/tpm/eventlog/tpm1.c:276:2: note: Value stored to 'len' is never read
len += get_event_name(eventname, event, event_entry);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 9 warnings (7 in non-user code, 2 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings generated.
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
drivers/char/tpm/tpm_tis_core.c:423:2: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/char/tpm/tpm_tis_core.c:423:2: note: Value stored to 'rc' is never read
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 7 warnings (6 in non-user code, 1 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
3 warnings generated.
Suppressed 3 warnings (3 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
3 warnings generated.
Suppressed 3 warnings (3 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
4 warnings generated.
Suppressed 4 warnings (4 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
5 warnings generated.
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
8 warnings generated.
mm/huge_memory.c:583:9: warning: Value stored to 'off' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
loff_t off = (loff_t)pgoff << PAGE_SHIFT;
^~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/huge_memory.c:583:9: note: Value stored to 'off' during its initialization is never read
loff_t off = (loff_t)pgoff << PAGE_SHIFT;
^~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores]
page = pmd_page(*pmd);
^
mm/huge_memory.c:2145:4: note: Value stored to 'page' is never read
mm/huge_memory.c:2991:4: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
strcpy(file_path, tok);
^~~~~~
mm/huge_memory.c:2991:4: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
strcpy(file_path, tok);
^~~~~~
Suppressed 5 warnings (5 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
mm/khugepaged.c:1651:3: warning: Value stored to 'result' is never read [clang-analyzer-deadcode.DeadStores]
result = SCAN_ALLOC_HUGE_PAGE_FAIL;
^ ~~~~~~~~~~~~~~~~~~~~~~~~~
mm/khugepaged.c:1651:3: note: Value stored to 'result' is never read
result = SCAN_ALLOC_HUGE_PAGE_FAIL;
^ ~~~~~~~~~~~~~~~~~~~~~~~~~
mm/khugepaged.c:1656:3: warning: Value stored to 'result' is never read [clang-analyzer-deadcode.DeadStores]
result = SCAN_CGROUP_CHARGE_FAIL;
^ ~~~~~~~~~~~~~~~~~~~~~~~
mm/khugepaged.c:1656:3: note: Value stored to 'result' is never read
result = SCAN_CGROUP_CHARGE_FAIL;
^ ~~~~~~~~~~~~~~~~~~~~~~~
mm/khugepaged.c:1672:4: warning: Value stored to 'result' is never read [clang-analyzer-deadcode.DeadStores]
result = SCAN_FAIL;
^ ~~~~~~~~~
mm/khugepaged.c:1672:4: note: Value stored to 'result' is never read
result = SCAN_FAIL;
^ ~~~~~~~~~
mm/khugepaged.c:1904:3: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
list_for_each_entry_safe(page, tmp, &pagelist, lru) {
^
include/linux/list.h:726:7: note: expanded from macro 'list_for_each_entry_safe'
n = list_next_entry(pos, member); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/list.h:564:2: note: expanded from macro 'list_next_entry'
list_entry((pos)->member.next, typeof(*(pos)), member)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/list.h:520:2: note: expanded from macro 'list_entry'
container_of(ptr, type, member)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/container_of.h:18:2: note: expanded from macro 'container_of'
void *__mptr = (void *)(ptr); \
^ ~~~~~~~~~~~~~
mm/khugepaged.c:1638:2: note: '?' condition is false
XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER);
^
include/linux/xarray.h:1367:21: note: expanded from macro 'XA_STATE_ORDER'
order - (order % XA_CHUNK_SHIFT), \
^
include/linux/xarray.h:1110:26: note: expanded from macro 'XA_CHUNK_SHIFT'
#define XA_CHUNK_SHIFT (CONFIG_BASE_SMALL ? 4 : 6)
^
./include/generated/autoconf.h:2359:27: note: expanded from macro 'CONFIG_BASE_SMALL'
#define CONFIG_BASE_SMALL 0
^
mm/khugepaged.c:1638:2: note: '?' condition is false
XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER);
^
include/linux/xarray.h:1368:20: note: expanded from macro 'XA_STATE_ORDER'
(1U << (order % XA_CHUNK_SHIFT)) - 1)
^
include/linux/xarray.h:1110:26: note: expanded from macro 'XA_CHUNK_SHIFT'
#define XA_CHUNK_SHIFT (CONFIG_BASE_SMALL ? 4 : 6)
^
./include/generated/autoconf.h:2359:27: note: expanded from macro 'CONFIG_BASE_SMALL'
#define CONFIG_BASE_SMALL 0
^
mm/khugepaged.c:1643:12: note: Left side of '&&' is true
VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
^
mm/khugepaged.c:1643:56: note: Assuming 'is_shmem' is true
VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
^
include/linux/mmdebug.h:17:32: note: expanded from macro 'VM_BUG_ON'
#define VM_BUG_ON(cond) BUG_ON(cond)
^~~~
include/asm-generic/bug.h:65:45: note: expanded from macro 'BUG_ON'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^~~~~~~~~
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
mm/khugepaged.c:1643:2: note: Taking false branch
VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
^
include/linux/mmdebug.h:17:25: note: expanded from macro 'VM_BUG_ON'
#define VM_BUG_ON(cond) BUG_ON(cond)
^
include/asm-generic/bug.h:65:32: note: expanded from macro 'BUG_ON'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
mm/khugepaged.c:1643:2: note: Loop condition is false. Exiting loop
VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
^
include/linux/mmdebug.h:17:25: note: expanded from macro 'VM_BUG_ON'
#define VM_BUG_ON(cond) BUG_ON(cond)
^
include/asm-generic/bug.h:65:27: note: expanded from macro 'BUG_ON'
vim +/page +2145 mm/huge_memory.c
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2119
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2120 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
33f4751e99601b Naoya Horiguchi 2016-07-14 2121 unsigned long address, bool freeze, struct page *page)
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2122 {
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2123 spinlock_t *ptl;
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2124 struct mmu_notifier_range range;
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2125
7269f999934b28 Jérôme Glisse 2019-05-13 2126 mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
6f4f13e8d9e27c Jérôme Glisse 2019-05-13 2127 address & HPAGE_PMD_MASK,
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2128 (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE);
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2129 mmu_notifier_invalidate_range_start(&range);
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2130 ptl = pmd_lock(vma->vm_mm, pmd);
33f4751e99601b Naoya Horiguchi 2016-07-14 2131
33f4751e99601b Naoya Horiguchi 2016-07-14 2132 /*
33f4751e99601b Naoya Horiguchi 2016-07-14 2133 * If caller asks to setup a migration entries, we need a page to check
33f4751e99601b Naoya Horiguchi 2016-07-14 2134 * pmd against. Otherwise we can end up replacing wrong page.
33f4751e99601b Naoya Horiguchi 2016-07-14 2135 */
33f4751e99601b Naoya Horiguchi 2016-07-14 2136 VM_BUG_ON(freeze && !page);
c444eb564fb166 Andrea Arcangeli 2020-05-27 2137 if (page) {
c444eb564fb166 Andrea Arcangeli 2020-05-27 2138 VM_WARN_ON_ONCE(!PageLocked(page));
c444eb564fb166 Andrea Arcangeli 2020-05-27 2139 if (page != pmd_page(*pmd))
33f4751e99601b Naoya Horiguchi 2016-07-14 2140 goto out;
c444eb564fb166 Andrea Arcangeli 2020-05-27 2141 }
33f4751e99601b Naoya Horiguchi 2016-07-14 2142
5c7fb56e5e3f70 Dan Williams 2016-01-15 2143 if (pmd_trans_huge(*pmd)) {
dbe67be3d9f30a David Hildenbrand 2022-02-16 2144 if (!page)
33f4751e99601b Naoya Horiguchi 2016-07-14 @2145 page = pmd_page(*pmd);
84c3fc4e9c563d Zi Yan 2017-09-08 2146 } else if (!(pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd)))
5c7fb56e5e3f70 Dan Williams 2016-01-15 2147 goto out;
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2148 __split_huge_pmd_locked(vma, pmd, range.start, freeze);
e90309c9f7722d Kirill A. Shutemov 2016-01-15 2149 out:
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2150 spin_unlock(ptl);
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2151 /*
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2152 * No need to double call mmu_notifier->invalidate_range() callback.
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2153 * They are 3 cases to consider inside __split_huge_pmd_locked():
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2154 * 1) pmdp_huge_clear_flush_notify() call invalidate_range() obvious
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2155 * 2) __split_huge_zero_page_pmd() read only zero page and any write
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2156 * fault will trigger a flush_notify before pointing to a new page
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2157 * (it is fine if the secondary mmu keeps pointing to the old zero
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2158 * page in the meantime)
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2159 * 3) Split a huge pmd into pte pointing to the same page. No need
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2160 * to invalidate secondary tlb entry they are all still valid.
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2161 * any further changes to individual pte will notify. So no need
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2162 * to call mmu_notifier->invalidate_range()
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2163 */
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2164 mmu_notifier_invalidate_range_only_end(&range);
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2165 }
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2166
:::::: The code at line 2145 was first introduced by commit
:::::: 33f4751e99601b7bfd1d66aedabd3ee9140922de mm: thp: move pmd check inside ptl for freeze_page()
:::::: TO: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
^ permalink raw reply [flat|nested] 2+ messages in thread
* [linux-next:master 5970/6564] mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores]
2022-02-22 1:23 [linux-next:master 5970/6564] mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores] kernel test robot
@ 2022-02-22 9:05 ` kernel test robot
0 siblings, 0 replies; 2+ messages in thread
From: kernel test robot @ 2022-02-22 9:05 UTC (permalink / raw)
To: Hugh Dickins
Cc: llvm, kbuild-all, Linux Memory Management List, Andrew Morton,
Linux Memory Management List
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: 3c30cf91b5ecc7272b3d2942ae0505dd8320b81c
commit: c1879365d325d0f44337fedcfffe8bf200092f95 [5970/6564] mm/munlock: rmap call mlock_vma_page() munlock_vma_page()
config: x86_64-randconfig-c007-20220221 (https://download.01.org/0day-ci/archive/20220222/202202220917.CFUvfxmY-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c1879365d325d0f44337fedcfffe8bf200092f95
git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout c1879365d325d0f44337fedcfffe8bf200092f95
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <yujie.liu@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
>> mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores]
page = pmd_page(*pmd);
^
vim +/page +2145 mm/huge_memory.c
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2119
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2120 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
33f4751e99601b Naoya Horiguchi 2016-07-14 2121 unsigned long address, bool freeze, struct page *page)
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2122 {
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2123 spinlock_t *ptl;
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2124 struct mmu_notifier_range range;
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2125
7269f999934b28 Jérôme Glisse 2019-05-13 2126 mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
6f4f13e8d9e27c Jérôme Glisse 2019-05-13 2127 address & HPAGE_PMD_MASK,
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2128 (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE);
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2129 mmu_notifier_invalidate_range_start(&range);
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2130 ptl = pmd_lock(vma->vm_mm, pmd);
33f4751e99601b Naoya Horiguchi 2016-07-14 2131
33f4751e99601b Naoya Horiguchi 2016-07-14 2132 /*
33f4751e99601b Naoya Horiguchi 2016-07-14 2133 * If caller asks to setup a migration entries, we need a page to check
33f4751e99601b Naoya Horiguchi 2016-07-14 2134 * pmd against. Otherwise we can end up replacing wrong page.
33f4751e99601b Naoya Horiguchi 2016-07-14 2135 */
33f4751e99601b Naoya Horiguchi 2016-07-14 2136 VM_BUG_ON(freeze && !page);
c444eb564fb166 Andrea Arcangeli 2020-05-27 2137 if (page) {
c444eb564fb166 Andrea Arcangeli 2020-05-27 2138 VM_WARN_ON_ONCE(!PageLocked(page));
c444eb564fb166 Andrea Arcangeli 2020-05-27 2139 if (page != pmd_page(*pmd))
33f4751e99601b Naoya Horiguchi 2016-07-14 2140 goto out;
c444eb564fb166 Andrea Arcangeli 2020-05-27 2141 }
33f4751e99601b Naoya Horiguchi 2016-07-14 2142
5c7fb56e5e3f70 Dan Williams 2016-01-15 2143 if (pmd_trans_huge(*pmd)) {
dbe67be3d9f30a David Hildenbrand 2022-02-16 2144 if (!page)
33f4751e99601b Naoya Horiguchi 2016-07-14 @2145 page = pmd_page(*pmd);
84c3fc4e9c563d Zi Yan 2017-09-08 2146 } else if (!(pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd)))
5c7fb56e5e3f70 Dan Williams 2016-01-15 2147 goto out;
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2148 __split_huge_pmd_locked(vma, pmd, range.start, freeze);
e90309c9f7722d Kirill A. Shutemov 2016-01-15 2149 out:
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2150 spin_unlock(ptl);
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2151 /*
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2152 * No need to double call mmu_notifier->invalidate_range() callback.
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2153 * They are 3 cases to consider inside __split_huge_pmd_locked():
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2154 * 1) pmdp_huge_clear_flush_notify() call invalidate_range() obvious
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2155 * 2) __split_huge_zero_page_pmd() read only zero page and any write
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2156 * fault will trigger a flush_notify before pointing to a new page
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2157 * (it is fine if the secondary mmu keeps pointing to the old zero
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2158 * page in the meantime)
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2159 * 3) Split a huge pmd into pte pointing to the same page. No need
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2160 * to invalidate secondary tlb entry they are all still valid.
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2161 * any further changes to individual pte will notify. So no need
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2162 * to call mmu_notifier->invalidate_range()
4645b9fe84bf48 Jérôme Glisse 2017-11-15 2163 */
ac46d4f3c43241 Jérôme Glisse 2018-12-28 2164 mmu_notifier_invalidate_range_only_end(&range);
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2165 }
eef1b3ba053aa6 Kirill A. Shutemov 2016-01-15 2166
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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2022-02-22 1:23 [linux-next:master 5970/6564] mm/huge_memory.c:2145:4: warning: Value stored to 'page' is never read [clang-analyzer-deadcode.DeadStores] kernel test robot
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