Re: [PATCH] uprobes: Use better bitmap_zalloc()

From: kernel test robot
Date: Sat May 29 2021 - 09:24:39 EST


Hi Kefeng,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/perf/core]
[also build test WARNING on linux/master linus/master v5.13-rc3 next-20210528]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Kefeng-Wang/uprobes-Use-better-bitmap_zalloc/20210529-190812
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 875dd7bf548104bc1d2c5784a6af6cf38215a216
config: x86_64-randconfig-a006-20210529 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project bc6799f2f79f0ae87e9f1ebf9d25ba799fbd25a9)
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 x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/346b85395aa484f7b3b64a53e197bc7f56a4e719
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kefeng-Wang/uprobes-Use-better-bitmap_zalloc/20210529-190812
git checkout 346b85395aa484f7b3b64a53e197bc7f56a4e719
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

kernel/events/uprobes.c:1490:17: error: implicit declaration of function 'bitmap_kzalloc' [-Werror,-Wimplicit-function-declaration]
area->bitmap = bitmap_kzalloc(UINSNS_PER_PAGE, GFP_KERNEL);
^
kernel/events/uprobes.c:1490:17: note: did you mean 'bitmap_zalloc'?
include/linux/bitmap.h:125:16: note: 'bitmap_zalloc' declared here
unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
^
>> kernel/events/uprobes.c:1490:15: warning: incompatible integer to pointer conversion assigning to 'unsigned long *' from 'int' [-Wint-conversion]
area->bitmap = bitmap_kzalloc(UINSNS_PER_PAGE, GFP_KERNEL);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/events/uprobes.c:1514:2: error: implicit declaration of function 'bitmap_kfree' [-Werror,-Wimplicit-function-declaration]
bitmap_kfree(area->bitmap);
^
kernel/events/uprobes.c:1514:2: note: did you mean 'bitmap_free'?
include/linux/bitmap.h:126:6: note: 'bitmap_free' declared here
void bitmap_free(const unsigned long *bitmap);
^
kernel/events/uprobes.c:1555:2: error: implicit declaration of function 'bitmap_kfree' [-Werror,-Wimplicit-function-declaration]
bitmap_kfree(area->bitmap);
^
1 warning and 3 errors generated.


vim +1490 kernel/events/uprobes.c

1479
1480 static struct xol_area *__create_xol_area(unsigned long vaddr)
1481 {
1482 struct mm_struct *mm = current->mm;
1483 uprobe_opcode_t insn = UPROBE_SWBP_INSN;
1484 struct xol_area *area;
1485
1486 area = kmalloc(sizeof(*area), GFP_KERNEL);
1487 if (unlikely(!area))
1488 goto out;
1489
> 1490 area->bitmap = bitmap_kzalloc(UINSNS_PER_PAGE, GFP_KERNEL);
1491 if (!area->bitmap)
1492 goto free_area;
1493
1494 area->xol_mapping.name = "[uprobes]";
1495 area->xol_mapping.fault = NULL;
1496 area->xol_mapping.pages = area->pages;
1497 area->pages[0] = alloc_page(GFP_HIGHUSER);
1498 if (!area->pages[0])
1499 goto free_bitmap;
1500 area->pages[1] = NULL;
1501
1502 area->vaddr = vaddr;
1503 init_waitqueue_head(&area->wq);
1504 /* Reserve the 1st slot for get_trampoline_vaddr() */
1505 set_bit(0, area->bitmap);
1506 atomic_set(&area->slot_count, 1);
1507 arch_uprobe_copy_ixol(area->pages[0], 0, &insn, UPROBE_SWBP_INSN_SIZE);
1508
1509 if (!xol_add_vma(mm, area))
1510 return area;
1511
1512 __free_page(area->pages[0]);
1513 free_bitmap:
1514 bitmap_kfree(area->bitmap);
1515 free_area:
1516 kfree(area);
1517 out:
1518 return NULL;
1519 }
1520

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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