* Re: [PATCH v2 tip/perf/core 5/5] uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
[not found] <20241001225207.2215639-6-andrii@kernel.org>
@ 2024-10-05 1:12 ` kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2024-10-05 1:12 UTC (permalink / raw)
To: Andrii Nakryiko, linux-trace-kernel, peterz, oleg
Cc: llvm, oe-kbuild-all, rostedt, mhiramat, bpf, linux-kernel, jolsa,
paulmck, willy, surenb, akpm, linux-mm, mjguzik, brauner, jannh,
mhocko, vbabka, mingo, Andrii Nakryiko
Hi Andrii,
kernel test robot noticed the following build errors:
[auto build test ERROR on tip/perf/core]
url: https://github.com/intel-lab-lkp/linux/commits/Andrii-Nakryiko/mm-introduce-mmap_lock_speculation_-start-end/20241002-065354
base: tip/perf/core
patch link: https://lore.kernel.org/r/20241001225207.2215639-6-andrii%40kernel.org
patch subject: [PATCH v2 tip/perf/core 5/5] uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
config: i386-defconfig (https://download.01.org/0day-ci/archive/20241005/202410050846.Zbsm9OI1-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241005/202410050846.Zbsm9OI1-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410050846.Zbsm9OI1-lkp@intel.com/
All errors (new ones prefixed by >>):
>> kernel/events/uprobes.c:2098:39: error: incompatible pointer types passing 'long *' to parameter of type 'int *' [-Werror,-Wincompatible-pointer-types]
2098 | if (!mmap_lock_speculation_start(mm, &seq))
| ^~~~
include/linux/mmap_lock.h:126:75: note: passing argument to parameter 'seq' here
126 | static inline bool mmap_lock_speculation_start(struct mm_struct *mm, int *seq) { return false; }
| ^
1 error generated.
vim +2098 kernel/events/uprobes.c
2086
2087 static struct uprobe *find_active_uprobe_speculative(unsigned long bp_vaddr)
2088 {
2089 struct mm_struct *mm = current->mm;
2090 struct uprobe *uprobe = NULL;
2091 struct vm_area_struct *vma;
2092 struct file *vm_file;
2093 loff_t offset;
2094 long seq;
2095
2096 guard(rcu)();
2097
> 2098 if (!mmap_lock_speculation_start(mm, &seq))
2099 return NULL;
2100
2101 vma = vma_lookup(mm, bp_vaddr);
2102 if (!vma)
2103 return NULL;
2104
2105 /* vm_file memory can be reused for another instance of struct file,
2106 * but can't be freed from under us, so it's safe to read fields from
2107 * it, even if the values are some garbage values; ultimately
2108 * find_uprobe_rcu() + mmap_lock_speculation_end() check will ensure
2109 * that whatever we speculatively found is correct
2110 */
2111 vm_file = READ_ONCE(vma->vm_file);
2112 if (!vm_file)
2113 return NULL;
2114
2115 offset = (loff_t)(vma->vm_pgoff << PAGE_SHIFT) + (bp_vaddr - vma->vm_start);
2116 uprobe = find_uprobe_rcu(vm_file->f_inode, offset);
2117 if (!uprobe)
2118 return NULL;
2119
2120 /* now double check that nothing about MM changed */
2121 if (!mmap_lock_speculation_end(mm, seq))
2122 return NULL;
2123
2124 return uprobe;
2125 }
2126
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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