* include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
@ 2021-12-13 21:45 kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-12-13 21:45 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 16208 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Jakub Jelinek <jakub@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
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/torvalds/linux.git master
head: 2585cf9dfaaddf00b069673f27bb3f8530e2039c
commit: 2f78788b55baa3410b1ec91a576286abe1ad4d6a ilog2: improve ilog2 for constant arguments
date: 12 months ago
:::::: branch date: 23 hours ago
:::::: commit date: 12 months ago
config: riscv-randconfig-c006-20211128 (https://download.01.org/0day-ci/archive/20211214/202112140515.JJMNX3pt-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4b553297ef3ee4dc2119d5429adf3072e90fac38)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f78788b55baa3410b1ec91a576286abe1ad4d6a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2f78788b55baa3410b1ec91a576286abe1ad4d6a
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:6: note: Left side of '&&' is true
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:2: note: Taking false branch
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:6: note: Assuming 'r' is 0
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:2: note: Taking false branch
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:7: note: 'nodes' is null
if (nodes) {
^~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:3: note: Taking false branch
if (nodes) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:7: note: 'pages_addr' is null
if (pages_addr) {
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:3: note: Taking false branch
if (pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1691:10: note: Taking true branch
} else if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1697:7: note: Calling 'amdgpu_vm_update_ptes'
r = amdgpu_vm_update_ptes(¶ms, start, tmp, addr, flags);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Calling 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:6: note: Assuming field 'asic_type' is >= CHIP_VEGA10
if (params->adev->asic_type < CHIP_VEGA10)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:2: note: Taking false branch
if (params->adev->asic_type < CHIP_VEGA10)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:6: note: Assuming field 'pages_addr' is non-null
if (params->pages_addr) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:2: note: Taking true branch
if (params->pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1404:3: note: Returning without writing to 'params->unlocked', which participates in a condition later
return;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Returning from 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:9: note: Assuming 'end' is > field 'pfn'
while (cursor.pfn < end) {
^~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:2: note: Loop condition is true. Entering loop body
while (cursor.pfn < end) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:7: note: Assuming field 'unlocked' is true
if (!params->unlocked) {
^~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:3: note: Taking false branch
if (!params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Calling 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:125:2: note: Control jumps to the 'default' case at line 133
switch (level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:134:3: note: Returning the value 4294967295
return ~0;
^~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Returning from 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:3: note: The value 4294967295 is assigned to 'shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:15: note: Field 'unlocked' is true
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:3: note: Taking true branch
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:8: note: Assuming the condition is false
if (amdgpu_vm_pt_descendant(adev, &cursor))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:4: note: Taking false branch
if (amdgpu_vm_pt_descendant(adev, &cursor))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:7: note: Assuming 'pt' is non-null
if (!pt) {
^~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:3: note: Taking false branch
if (!pt) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1510:41: note: The result of the left shift is undefined due to shifting by '4294967295', which is greater or equal to the width of type 'uint64_t'
incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
^ ~~~~~
>> include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
__u32 h = x >> 32;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:6: note: Assuming the condition is true
if (amdgpu_vm_size != -1) {
^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:2: note: Taking true branch
if (amdgpu_vm_size != -1) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:7: note: Assuming 'vm_size' is <= 'max_size'
if (vm_size > max_size) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:3: note: Taking false branch
if (vm_size > max_size) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2712:8: note: '?' condition is false
tmp = roundup_pow_of_two(adev->vm_manager.max_pfn);
^
include/linux/log2.h:176:2: note: expanded from macro 'roundup_pow_of_two'
__builtin_constant_p(n) ? ( \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: Assuming '__UNIQUE_ID___x451' is >= '__UNIQUE_ID___y452'
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: '?' condition is false
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2717:2: note: Control jumps to the 'default' case@line 2727
switch (adev->vm_manager.num_level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:11: note: Assuming field 'num_level' is <= 1
else if (adev->vm_manager.num_level > 1)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:7: note: Taking false branch
else if (adev->vm_manager.num_level > 1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2739:33: note: Calling 'amdgpu_vm_get_block_size'
adev->vm_manager.block_size = amdgpu_vm_get_block_size(tmp);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:158:2: note: expanded from macro 'ilog2'
__builtin_constant_p(n) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:161:2: note: expanded from macro 'ilog2'
(sizeof(n) <= 4) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: Calling '__ilog2_u64'
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:163:2: note: expanded from macro 'ilog2'
__ilog2_u64(n) \
^~~~~~~~~~~~~~
include/linux/log2.h:32:9: note: Calling 'fls64'
return fls64(n) - 1;
^~~~~~~~
include/asm-generic/bitops/fls64.h:21:14: note: The result of the '>>' expression is undefined
__u32 h = x >> 32;
~~^~~~~
include/linux/log2.h:57:13: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'unsigned long' [clang-analyzer-core.UndefinedBinaryOperatorResult]
return 1UL << fls_long(n - 1);
vim +21 include/asm-generic/bitops/fls64.h
a54baa1487c51c Akinobu Mita 2006-03-26 6
d57594c203b1e7 Alexander van Heukelum 2008-03-15 7 /**
d57594c203b1e7 Alexander van Heukelum 2008-03-15 8 * fls64 - find last set bit in a 64-bit word
d57594c203b1e7 Alexander van Heukelum 2008-03-15 9 * @x: the word to search
d57594c203b1e7 Alexander van Heukelum 2008-03-15 10 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 11 * This is defined in a similar way as the libc and compiler builtin
d57594c203b1e7 Alexander van Heukelum 2008-03-15 12 * ffsll, but returns the position of the most significant set bit.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 13 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 14 * fls64(value) returns 0 if value is 0 or the position of the last
d57594c203b1e7 Alexander van Heukelum 2008-03-15 15 * set bit if value is nonzero. The last (most significant) bit is
d57594c203b1e7 Alexander van Heukelum 2008-03-15 16 *@position 64.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 17 */
d57594c203b1e7 Alexander van Heukelum 2008-03-15 18 #if BITS_PER_LONG == 32
c8399943bdb70f Andi Kleen 2009-01-12 19 static __always_inline int fls64(__u64 x)
2dfc383ad587bb Akinobu Mita 2006-03-26 20 {
2dfc383ad587bb Akinobu Mita 2006-03-26 @21 __u32 h = x >> 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 22 if (h)
2dfc383ad587bb Akinobu Mita 2006-03-26 23 return fls(h) + 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 24 return fls(x);
2dfc383ad587bb Akinobu Mita 2006-03-26 25 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 26 #elif BITS_PER_LONG == 64
c8399943bdb70f Andi Kleen 2009-01-12 27 static __always_inline int fls64(__u64 x)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 28 {
d57594c203b1e7 Alexander van Heukelum 2008-03-15 29 if (x == 0)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 30 return 0;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 31 return __fls(x) + 1;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 32 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 33 #else
d57594c203b1e7 Alexander van Heukelum 2008-03-15 34 #error BITS_PER_LONG not 32 or 64
d57594c203b1e7 Alexander van Heukelum 2008-03-15 35 #endif
2dfc383ad587bb Akinobu Mita 2006-03-26 36
:::::: The code at line 21 was first introduced by commit
:::::: 2dfc383ad587bbead84739a9ff9273df3eda983d [PATCH] bitops: generic fls64()
:::::: TO: Akinobu Mita <mita@miraclelinux.com>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.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] 4+ messages in thread
* include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
@ 2021-12-13 2:33 kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-12-13 2:33 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 16208 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Jakub Jelinek <jakub@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
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/torvalds/linux.git master
head: a763d5a5abd65797aec3dd1bf01fe2ccbec32967
commit: 2f78788b55baa3410b1ec91a576286abe1ad4d6a ilog2: improve ilog2 for constant arguments
date: 12 months ago
:::::: branch date: 26 hours ago
:::::: commit date: 12 months ago
config: riscv-randconfig-c006-20211128 (https://download.01.org/0day-ci/archive/20211213/202112131045.es1rz6j5-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4b553297ef3ee4dc2119d5429adf3072e90fac38)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f78788b55baa3410b1ec91a576286abe1ad4d6a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2f78788b55baa3410b1ec91a576286abe1ad4d6a
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:6: note: Left side of '&&' is true
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:2: note: Taking false branch
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:6: note: Assuming 'r' is 0
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:2: note: Taking false branch
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:7: note: 'nodes' is null
if (nodes) {
^~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:3: note: Taking false branch
if (nodes) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:7: note: 'pages_addr' is null
if (pages_addr) {
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:3: note: Taking false branch
if (pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1691:10: note: Taking true branch
} else if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1697:7: note: Calling 'amdgpu_vm_update_ptes'
r = amdgpu_vm_update_ptes(¶ms, start, tmp, addr, flags);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Calling 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:6: note: Assuming field 'asic_type' is >= CHIP_VEGA10
if (params->adev->asic_type < CHIP_VEGA10)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:2: note: Taking false branch
if (params->adev->asic_type < CHIP_VEGA10)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:6: note: Assuming field 'pages_addr' is non-null
if (params->pages_addr) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:2: note: Taking true branch
if (params->pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1404:3: note: Returning without writing to 'params->unlocked', which participates in a condition later
return;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Returning from 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:9: note: Assuming 'end' is > field 'pfn'
while (cursor.pfn < end) {
^~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:2: note: Loop condition is true. Entering loop body
while (cursor.pfn < end) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:7: note: Assuming field 'unlocked' is true
if (!params->unlocked) {
^~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:3: note: Taking false branch
if (!params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Calling 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:125:2: note: Control jumps to the 'default' case at line 133
switch (level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:134:3: note: Returning the value 4294967295
return ~0;
^~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Returning from 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:3: note: The value 4294967295 is assigned to 'shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:15: note: Field 'unlocked' is true
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:3: note: Taking true branch
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:8: note: Assuming the condition is false
if (amdgpu_vm_pt_descendant(adev, &cursor))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:4: note: Taking false branch
if (amdgpu_vm_pt_descendant(adev, &cursor))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:7: note: Assuming 'pt' is non-null
if (!pt) {
^~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:3: note: Taking false branch
if (!pt) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1510:41: note: The result of the left shift is undefined due to shifting by '4294967295', which is greater or equal to the width of type 'uint64_t'
incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
^ ~~~~~
>> include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
__u32 h = x >> 32;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:6: note: Assuming the condition is true
if (amdgpu_vm_size != -1) {
^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:2: note: Taking true branch
if (amdgpu_vm_size != -1) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:7: note: Assuming 'vm_size' is <= 'max_size'
if (vm_size > max_size) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:3: note: Taking false branch
if (vm_size > max_size) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2712:8: note: '?' condition is false
tmp = roundup_pow_of_two(adev->vm_manager.max_pfn);
^
include/linux/log2.h:176:2: note: expanded from macro 'roundup_pow_of_two'
__builtin_constant_p(n) ? ( \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: Assuming '__UNIQUE_ID___x451' is >= '__UNIQUE_ID___y452'
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: '?' condition is false
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2717:2: note: Control jumps to the 'default' case@line 2727
switch (adev->vm_manager.num_level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:11: note: Assuming field 'num_level' is <= 1
else if (adev->vm_manager.num_level > 1)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:7: note: Taking false branch
else if (adev->vm_manager.num_level > 1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2739:33: note: Calling 'amdgpu_vm_get_block_size'
adev->vm_manager.block_size = amdgpu_vm_get_block_size(tmp);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:158:2: note: expanded from macro 'ilog2'
__builtin_constant_p(n) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:161:2: note: expanded from macro 'ilog2'
(sizeof(n) <= 4) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: Calling '__ilog2_u64'
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:163:2: note: expanded from macro 'ilog2'
__ilog2_u64(n) \
^~~~~~~~~~~~~~
include/linux/log2.h:32:9: note: Calling 'fls64'
return fls64(n) - 1;
^~~~~~~~
include/asm-generic/bitops/fls64.h:21:14: note: The result of the '>>' expression is undefined
__u32 h = x >> 32;
~~^~~~~
include/linux/log2.h:57:13: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'unsigned long' [clang-analyzer-core.UndefinedBinaryOperatorResult]
return 1UL << fls_long(n - 1);
vim +21 include/asm-generic/bitops/fls64.h
a54baa1487c51c Akinobu Mita 2006-03-26 6
d57594c203b1e7 Alexander van Heukelum 2008-03-15 7 /**
d57594c203b1e7 Alexander van Heukelum 2008-03-15 8 * fls64 - find last set bit in a 64-bit word
d57594c203b1e7 Alexander van Heukelum 2008-03-15 9 * @x: the word to search
d57594c203b1e7 Alexander van Heukelum 2008-03-15 10 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 11 * This is defined in a similar way as the libc and compiler builtin
d57594c203b1e7 Alexander van Heukelum 2008-03-15 12 * ffsll, but returns the position of the most significant set bit.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 13 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 14 * fls64(value) returns 0 if value is 0 or the position of the last
d57594c203b1e7 Alexander van Heukelum 2008-03-15 15 * set bit if value is nonzero. The last (most significant) bit is
d57594c203b1e7 Alexander van Heukelum 2008-03-15 16 *@position 64.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 17 */
d57594c203b1e7 Alexander van Heukelum 2008-03-15 18 #if BITS_PER_LONG == 32
c8399943bdb70f Andi Kleen 2009-01-12 19 static __always_inline int fls64(__u64 x)
2dfc383ad587bb Akinobu Mita 2006-03-26 20 {
2dfc383ad587bb Akinobu Mita 2006-03-26 @21 __u32 h = x >> 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 22 if (h)
2dfc383ad587bb Akinobu Mita 2006-03-26 23 return fls(h) + 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 24 return fls(x);
2dfc383ad587bb Akinobu Mita 2006-03-26 25 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 26 #elif BITS_PER_LONG == 64
c8399943bdb70f Andi Kleen 2009-01-12 27 static __always_inline int fls64(__u64 x)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 28 {
d57594c203b1e7 Alexander van Heukelum 2008-03-15 29 if (x == 0)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 30 return 0;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 31 return __fls(x) + 1;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 32 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 33 #else
d57594c203b1e7 Alexander van Heukelum 2008-03-15 34 #error BITS_PER_LONG not 32 or 64
d57594c203b1e7 Alexander van Heukelum 2008-03-15 35 #endif
2dfc383ad587bb Akinobu Mita 2006-03-26 36
:::::: The code at line 21 was first introduced by commit
:::::: 2dfc383ad587bbead84739a9ff9273df3eda983d [PATCH] bitops: generic fls64()
:::::: TO: Akinobu Mita <mita@miraclelinux.com>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.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] 4+ messages in thread
* include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
@ 2021-12-09 0:39 kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-12-09 0:39 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 16208 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Jakub Jelinek <jakub@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
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/torvalds/linux.git master
head: 2a987e65025e2b79c6d453b78cb5985ac6e5eb26
commit: 2f78788b55baa3410b1ec91a576286abe1ad4d6a ilog2: improve ilog2 for constant arguments
date: 12 months ago
:::::: branch date: 25 hours ago
:::::: commit date: 12 months ago
config: riscv-randconfig-c006-20211128 (https://download.01.org/0day-ci/archive/20211209/202112090844.wThBsVEB-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4b553297ef3ee4dc2119d5429adf3072e90fac38)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f78788b55baa3410b1ec91a576286abe1ad4d6a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2f78788b55baa3410b1ec91a576286abe1ad4d6a
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:6: note: Left side of '&&' is true
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:2: note: Taking false branch
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:6: note: Assuming 'r' is 0
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:2: note: Taking false branch
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:7: note: 'nodes' is null
if (nodes) {
^~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:3: note: Taking false branch
if (nodes) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:7: note: 'pages_addr' is null
if (pages_addr) {
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:3: note: Taking false branch
if (pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1691:10: note: Taking true branch
} else if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1697:7: note: Calling 'amdgpu_vm_update_ptes'
r = amdgpu_vm_update_ptes(¶ms, start, tmp, addr, flags);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Calling 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:6: note: Assuming field 'asic_type' is >= CHIP_VEGA10
if (params->adev->asic_type < CHIP_VEGA10)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:2: note: Taking false branch
if (params->adev->asic_type < CHIP_VEGA10)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:6: note: Assuming field 'pages_addr' is non-null
if (params->pages_addr) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:2: note: Taking true branch
if (params->pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1404:3: note: Returning without writing to 'params->unlocked', which participates in a condition later
return;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Returning from 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:9: note: Assuming 'end' is > field 'pfn'
while (cursor.pfn < end) {
^~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:2: note: Loop condition is true. Entering loop body
while (cursor.pfn < end) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:7: note: Assuming field 'unlocked' is true
if (!params->unlocked) {
^~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:3: note: Taking false branch
if (!params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Calling 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:125:2: note: Control jumps to the 'default' case at line 133
switch (level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:134:3: note: Returning the value 4294967295
return ~0;
^~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Returning from 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:3: note: The value 4294967295 is assigned to 'shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:15: note: Field 'unlocked' is true
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:3: note: Taking true branch
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:8: note: Assuming the condition is false
if (amdgpu_vm_pt_descendant(adev, &cursor))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:4: note: Taking false branch
if (amdgpu_vm_pt_descendant(adev, &cursor))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:7: note: Assuming 'pt' is non-null
if (!pt) {
^~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:3: note: Taking false branch
if (!pt) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1510:41: note: The result of the left shift is undefined due to shifting by '4294967295', which is greater or equal to the width of type 'uint64_t'
incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
^ ~~~~~
>> include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
__u32 h = x >> 32;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:6: note: Assuming the condition is true
if (amdgpu_vm_size != -1) {
^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:2: note: Taking true branch
if (amdgpu_vm_size != -1) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:7: note: Assuming 'vm_size' is <= 'max_size'
if (vm_size > max_size) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:3: note: Taking false branch
if (vm_size > max_size) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2712:8: note: '?' condition is false
tmp = roundup_pow_of_two(adev->vm_manager.max_pfn);
^
include/linux/log2.h:176:2: note: expanded from macro 'roundup_pow_of_two'
__builtin_constant_p(n) ? ( \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: Assuming '__UNIQUE_ID___x451' is >= '__UNIQUE_ID___y452'
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: '?' condition is false
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2717:2: note: Control jumps to the 'default' case@line 2727
switch (adev->vm_manager.num_level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:11: note: Assuming field 'num_level' is <= 1
else if (adev->vm_manager.num_level > 1)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:7: note: Taking false branch
else if (adev->vm_manager.num_level > 1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2739:33: note: Calling 'amdgpu_vm_get_block_size'
adev->vm_manager.block_size = amdgpu_vm_get_block_size(tmp);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:158:2: note: expanded from macro 'ilog2'
__builtin_constant_p(n) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:161:2: note: expanded from macro 'ilog2'
(sizeof(n) <= 4) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: Calling '__ilog2_u64'
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:163:2: note: expanded from macro 'ilog2'
__ilog2_u64(n) \
^~~~~~~~~~~~~~
include/linux/log2.h:32:9: note: Calling 'fls64'
return fls64(n) - 1;
^~~~~~~~
include/asm-generic/bitops/fls64.h:21:14: note: The result of the '>>' expression is undefined
__u32 h = x >> 32;
~~^~~~~
include/linux/log2.h:57:13: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'unsigned long' [clang-analyzer-core.UndefinedBinaryOperatorResult]
return 1UL << fls_long(n - 1);
vim +21 include/asm-generic/bitops/fls64.h
a54baa1487c51c Akinobu Mita 2006-03-26 6
d57594c203b1e7 Alexander van Heukelum 2008-03-15 7 /**
d57594c203b1e7 Alexander van Heukelum 2008-03-15 8 * fls64 - find last set bit in a 64-bit word
d57594c203b1e7 Alexander van Heukelum 2008-03-15 9 * @x: the word to search
d57594c203b1e7 Alexander van Heukelum 2008-03-15 10 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 11 * This is defined in a similar way as the libc and compiler builtin
d57594c203b1e7 Alexander van Heukelum 2008-03-15 12 * ffsll, but returns the position of the most significant set bit.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 13 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 14 * fls64(value) returns 0 if value is 0 or the position of the last
d57594c203b1e7 Alexander van Heukelum 2008-03-15 15 * set bit if value is nonzero. The last (most significant) bit is
d57594c203b1e7 Alexander van Heukelum 2008-03-15 16 *@position 64.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 17 */
d57594c203b1e7 Alexander van Heukelum 2008-03-15 18 #if BITS_PER_LONG == 32
c8399943bdb70f Andi Kleen 2009-01-12 19 static __always_inline int fls64(__u64 x)
2dfc383ad587bb Akinobu Mita 2006-03-26 20 {
2dfc383ad587bb Akinobu Mita 2006-03-26 @21 __u32 h = x >> 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 22 if (h)
2dfc383ad587bb Akinobu Mita 2006-03-26 23 return fls(h) + 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 24 return fls(x);
2dfc383ad587bb Akinobu Mita 2006-03-26 25 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 26 #elif BITS_PER_LONG == 64
c8399943bdb70f Andi Kleen 2009-01-12 27 static __always_inline int fls64(__u64 x)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 28 {
d57594c203b1e7 Alexander van Heukelum 2008-03-15 29 if (x == 0)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 30 return 0;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 31 return __fls(x) + 1;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 32 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 33 #else
d57594c203b1e7 Alexander van Heukelum 2008-03-15 34 #error BITS_PER_LONG not 32 or 64
d57594c203b1e7 Alexander van Heukelum 2008-03-15 35 #endif
2dfc383ad587bb Akinobu Mita 2006-03-26 36
:::::: The code at line 21 was first introduced by commit
:::::: 2dfc383ad587bbead84739a9ff9273df3eda983d [PATCH] bitops: generic fls64()
:::::: TO: Akinobu Mita <mita@miraclelinux.com>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.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] 4+ messages in thread
* include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
@ 2021-12-04 6:24 kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-12-04 6:24 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 16208 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Jakub Jelinek <jakub@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
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/torvalds/linux.git master
head: 12119cfa1052d512a92524e90ebee85029a918f8
commit: 2f78788b55baa3410b1ec91a576286abe1ad4d6a ilog2: improve ilog2 for constant arguments
date: 12 months ago
:::::: branch date: 10 hours ago
:::::: commit date: 12 months ago
config: riscv-randconfig-c006-20211128 (https://download.01.org/0day-ci/archive/20211204/202112041446.zgvkGxJ5-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4b553297ef3ee4dc2119d5429adf3072e90fac38)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f78788b55baa3410b1ec91a576286abe1ad4d6a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2f78788b55baa3410b1ec91a576286abe1ad4d6a
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:6: note: Left side of '&&' is true
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1636:2: note: Taking false branch
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:6: note: Assuming 'r' is 0
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1645:2: note: Taking false branch
if (r)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:7: note: 'nodes' is null
if (nodes) {
^~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1653:3: note: Taking false branch
if (nodes) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:7: note: 'pages_addr' is null
if (pages_addr) {
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1661:3: note: Taking false branch
if (pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1691:10: note: Taking true branch
} else if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1697:7: note: Calling 'amdgpu_vm_update_ptes'
r = amdgpu_vm_update_ptes(¶ms, start, tmp, addr, flags);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Calling 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:6: note: Assuming field 'asic_type' is >= CHIP_VEGA10
if (params->adev->asic_type < CHIP_VEGA10)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1395:2: note: Taking false branch
if (params->adev->asic_type < CHIP_VEGA10)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:6: note: Assuming field 'pages_addr' is non-null
if (params->pages_addr) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1401:2: note: Taking true branch
if (params->pages_addr) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1404:3: note: Returning without writing to 'params->unlocked', which participates in a condition later
return;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1442:2: note: Returning from 'amdgpu_vm_fragment'
amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:9: note: Assuming 'end' is > field 'pfn'
while (cursor.pfn < end) {
^~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1446:2: note: Loop condition is true. Entering loop body
while (cursor.pfn < end) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:7: note: Assuming field 'unlocked' is true
if (!params->unlocked) {
^~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1451:3: note: Taking false branch
if (!params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Calling 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:125:2: note: Control jumps to the 'default' case at line 133
switch (level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:134:3: note: Returning the value 4294967295
return ~0;
^~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:11: note: Returning from 'amdgpu_vm_level_shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1461:3: note: The value 4294967295 is assigned to 'shift'
shift = amdgpu_vm_level_shift(adev, cursor.level);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:15: note: Field 'unlocked' is true
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1463:3: note: Taking true branch
if (params->unlocked) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:8: note: Assuming the condition is false
if (amdgpu_vm_pt_descendant(adev, &cursor))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1465:4: note: Taking false branch
if (amdgpu_vm_pt_descendant(adev, &cursor))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:7: note: Assuming 'pt' is non-null
if (!pt) {
^~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1492:3: note: Taking false branch
if (!pt) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1510:41: note: The result of the left shift is undefined due to shifting by '4294967295', which is greater or equal to the width of type 'uint64_t'
incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
^ ~~~~~
>> include/asm-generic/bitops/fls64.h:21:14: warning: The result of the '>>' expression is undefined [clang-analyzer-core.UndefinedBinaryOperatorResult]
__u32 h = x >> 32;
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:6: note: Assuming the condition is true
if (amdgpu_vm_size != -1) {
^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2677:2: note: Taking true branch
if (amdgpu_vm_size != -1) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:7: note: Assuming 'vm_size' is <= 'max_size'
if (vm_size > max_size) {
^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2679:3: note: Taking false branch
if (vm_size > max_size) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2712:8: note: '?' condition is false
tmp = roundup_pow_of_two(adev->vm_manager.max_pfn);
^
include/linux/log2.h:176:2: note: expanded from macro 'roundup_pow_of_two'
__builtin_constant_p(n) ? ( \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2713:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: Assuming '__UNIQUE_ID___x451' is >= '__UNIQUE_ID___y452'
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2716:31: note: '?' condition is false
adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
^
include/linux/minmax.h:51:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/minmax.h:44:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:39:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:34:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2717:2: note: Control jumps to the 'default' case@line 2727
switch (adev->vm_manager.num_level) {
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:6: note: Assuming the condition is false
if (amdgpu_vm_block_size != -1)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2731:2: note: Taking false branch
if (amdgpu_vm_block_size != -1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:11: note: Assuming field 'num_level' is <= 1
else if (adev->vm_manager.num_level > 1)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2736:7: note: Taking false branch
else if (adev->vm_manager.num_level > 1)
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2739:33: note: Calling 'amdgpu_vm_get_block_size'
adev->vm_manager.block_size = amdgpu_vm_get_block_size(tmp);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:158:2: note: expanded from macro 'ilog2'
__builtin_constant_p(n) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: '?' condition is false
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:161:2: note: expanded from macro 'ilog2'
(sizeof(n) <= 4) ? \
^
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2648:18: note: Calling '__ilog2_u64'
unsigned bits = ilog2(vm_size) + 18;
^
include/linux/log2.h:163:2: note: expanded from macro 'ilog2'
__ilog2_u64(n) \
^~~~~~~~~~~~~~
include/linux/log2.h:32:9: note: Calling 'fls64'
return fls64(n) - 1;
^~~~~~~~
include/asm-generic/bitops/fls64.h:21:14: note: The result of the '>>' expression is undefined
__u32 h = x >> 32;
~~^~~~~
include/linux/log2.h:57:13: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'unsigned long' [clang-analyzer-core.UndefinedBinaryOperatorResult]
return 1UL << fls_long(n - 1);
vim +21 include/asm-generic/bitops/fls64.h
a54baa1487c51c Akinobu Mita 2006-03-26 6
d57594c203b1e7 Alexander van Heukelum 2008-03-15 7 /**
d57594c203b1e7 Alexander van Heukelum 2008-03-15 8 * fls64 - find last set bit in a 64-bit word
d57594c203b1e7 Alexander van Heukelum 2008-03-15 9 * @x: the word to search
d57594c203b1e7 Alexander van Heukelum 2008-03-15 10 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 11 * This is defined in a similar way as the libc and compiler builtin
d57594c203b1e7 Alexander van Heukelum 2008-03-15 12 * ffsll, but returns the position of the most significant set bit.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 13 *
d57594c203b1e7 Alexander van Heukelum 2008-03-15 14 * fls64(value) returns 0 if value is 0 or the position of the last
d57594c203b1e7 Alexander van Heukelum 2008-03-15 15 * set bit if value is nonzero. The last (most significant) bit is
d57594c203b1e7 Alexander van Heukelum 2008-03-15 16 *@position 64.
d57594c203b1e7 Alexander van Heukelum 2008-03-15 17 */
d57594c203b1e7 Alexander van Heukelum 2008-03-15 18 #if BITS_PER_LONG == 32
c8399943bdb70f Andi Kleen 2009-01-12 19 static __always_inline int fls64(__u64 x)
2dfc383ad587bb Akinobu Mita 2006-03-26 20 {
2dfc383ad587bb Akinobu Mita 2006-03-26 @21 __u32 h = x >> 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 22 if (h)
2dfc383ad587bb Akinobu Mita 2006-03-26 23 return fls(h) + 32;
2dfc383ad587bb Akinobu Mita 2006-03-26 24 return fls(x);
2dfc383ad587bb Akinobu Mita 2006-03-26 25 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 26 #elif BITS_PER_LONG == 64
c8399943bdb70f Andi Kleen 2009-01-12 27 static __always_inline int fls64(__u64 x)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 28 {
d57594c203b1e7 Alexander van Heukelum 2008-03-15 29 if (x == 0)
d57594c203b1e7 Alexander van Heukelum 2008-03-15 30 return 0;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 31 return __fls(x) + 1;
d57594c203b1e7 Alexander van Heukelum 2008-03-15 32 }
d57594c203b1e7 Alexander van Heukelum 2008-03-15 33 #else
d57594c203b1e7 Alexander van Heukelum 2008-03-15 34 #error BITS_PER_LONG not 32 or 64
d57594c203b1e7 Alexander van Heukelum 2008-03-15 35 #endif
2dfc383ad587bb Akinobu Mita 2006-03-26 36
:::::: The code at line 21 was first introduced by commit
:::::: 2dfc383ad587bbead84739a9ff9273df3eda983d [PATCH] bitops: generic fls64()
:::::: TO: Akinobu Mita <mita@miraclelinux.com>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.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] 4+ messages in thread
end of thread, other threads:[~2021-12-13 21:45 UTC | newest]
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