Context |
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Description |
bpf/vmtest-bpf-next-PR |
success
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PR summary
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bpf/vmtest-bpf-next-VM_Test-0 |
success
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Logs for Lint
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bpf/vmtest-bpf-next-VM_Test-1 |
success
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Logs for ShellCheck
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bpf/vmtest-bpf-next-VM_Test-3 |
success
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Logs for Validate matrix.py
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bpf/vmtest-bpf-next-VM_Test-2 |
success
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Logs for Unittests
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bpf/vmtest-bpf-next-VM_Test-5 |
success
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Logs for aarch64-gcc / build-release
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bpf/vmtest-bpf-next-VM_Test-12 |
success
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Logs for s390x-gcc / build-release
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bpf/vmtest-bpf-next-VM_Test-15 |
success
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Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-4 |
success
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Logs for aarch64-gcc / build / build for aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-10 |
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Logs for aarch64-gcc / veristat
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bpf/vmtest-bpf-next-VM_Test-11 |
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Logs for s390x-gcc / build / build for s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-16 |
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Logs for s390x-gcc / veristat
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bpf/vmtest-bpf-next-VM_Test-9 |
success
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Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-17 |
success
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Logs for set-matrix
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bpf/vmtest-bpf-next-VM_Test-18 |
success
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Logs for x86_64-gcc / build / build for x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-19 |
success
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Logs for x86_64-gcc / build-release
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bpf/vmtest-bpf-next-VM_Test-20 |
success
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Logs for x86_64-gcc / test (test_maps, false, 360) / test_maps on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-23 |
success
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Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-24 |
success
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Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-25 |
success
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Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-26 |
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Logs for x86_64-gcc / veristat / veristat on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-27 |
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Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
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bpf/vmtest-bpf-next-VM_Test-28 |
success
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Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17-O2
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bpf/vmtest-bpf-next-VM_Test-29 |
success
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Logs for x86_64-llvm-17 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-17
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bpf/vmtest-bpf-next-VM_Test-32 |
success
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Logs for x86_64-llvm-17 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-17
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bpf/vmtest-bpf-next-VM_Test-33 |
success
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Logs for x86_64-llvm-17 / veristat
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bpf/vmtest-bpf-next-VM_Test-34 |
success
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Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-35 |
success
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Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18-O2
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bpf/vmtest-bpf-next-VM_Test-36 |
success
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Logs for x86_64-llvm-18 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-40 |
success
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Logs for x86_64-llvm-18 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-41 |
success
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Logs for x86_64-llvm-18 / veristat
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bpf/vmtest-bpf-next-VM_Test-14 |
success
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Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-7 |
success
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Logs for aarch64-gcc / test (test_progs, false, 360) / test_progs on aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-8 |
success
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Logs for aarch64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-6 |
success
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Logs for aarch64-gcc / test (test_maps, false, 360) / test_maps on aarch64 with gcc
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bpf/vmtest-bpf-next-VM_Test-21 |
success
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Logs for x86_64-gcc / test (test_progs, false, 360) / test_progs on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-22 |
success
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Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-30 |
success
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Logs for x86_64-llvm-17 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-17
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bpf/vmtest-bpf-next-VM_Test-31 |
success
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Logs for x86_64-llvm-17 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-17
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bpf/vmtest-bpf-next-VM_Test-37 |
success
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Logs for x86_64-llvm-18 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-38 |
success
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Logs for x86_64-llvm-18 / test (test_progs_cpuv4, false, 360) / test_progs_cpuv4 on x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-39 |
success
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Logs for x86_64-llvm-18 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-18
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bpf/vmtest-bpf-next-VM_Test-13 |
success
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Logs for s390x-gcc / test (test_progs, false, 360) / test_progs on s390x with gcc
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netdev/series_format |
success
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Posting correctly formatted
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netdev/tree_selection |
success
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Guessed tree name to be net-next
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netdev/ynl |
success
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Generated files up to date;
no warnings/errors;
no diff in generated;
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netdev/fixes_present |
success
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Fixes tag not required for -next series
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netdev/header_inline |
success
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No static functions without inline keyword in header files
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netdev/build_32bit |
success
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Errors and warnings before: 602 this patch: 602
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netdev/build_tools |
success
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Errors and warnings before: 0 this patch: 0
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netdev/cc_maintainers |
warning
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12 maintainers not CCed: vschneid@redhat.com peterz@infradead.org dietmar.eggemann@arm.com mgorman@suse.de vincent.guittot@linaro.org agruenba@redhat.com juri.lelli@redhat.com gregkh@linuxfoundation.org oleg@redhat.com dylanbhatch@google.com mingo@redhat.com bsegall@google.com
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netdev/build_clang |
success
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Errors and warnings before: 1091 this patch: 1091
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netdev/verify_signedoff |
success
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Signed-off-by tag matches author and committer
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netdev/deprecated_api |
success
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None detected
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netdev/check_selftest |
success
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No net selftest shell script
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netdev/verify_fixes |
success
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No Fixes tag
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netdev/build_allmodconfig_warn |
success
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Errors and warnings before: 15201 this patch: 15201
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netdev/checkpatch |
success
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total: 0 errors, 0 warnings, 0 checks, 77 lines checked
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netdev/build_clang_rust |
success
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No Rust files in patch. Skipping build
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netdev/kdoc |
success
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Errors and warnings before: 16 this patch: 16
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netdev/source_inline |
success
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Was 0 now: 0
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@@ -1264,16 +1264,6 @@ static int unshare_sighand(struct task_struct *me)
return 0;
}
-char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
-{
- task_lock(tsk);
- /* Always NUL terminated and zero-padded */
- strscpy_pad(buf, tsk->comm, buf_size);
- task_unlock(tsk);
- return buf;
-}
-EXPORT_SYMBOL_GPL(__get_task_comm);
-
/*
* These functions flushes out all traces of the currently running executable
* so that a new one can be started
@@ -109,7 +109,7 @@ void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape)
else if (p->flags & PF_KTHREAD)
get_kthread_comm(tcomm, sizeof(tcomm), p);
else
- __get_task_comm(tcomm, sizeof(tcomm), p);
+ get_task_comm(tcomm, p);
if (escape)
seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
@@ -1096,9 +1096,12 @@ struct task_struct {
/*
* executable name, excluding path.
*
- * - normally initialized setup_new_exec()
- * - access it with [gs]et_task_comm()
- * - lock it with task_lock()
+ * - normally initialized begin_new_exec()
+ * - set it with set_task_comm()
+ * - strscpy_pad() to ensure it is always NUL-terminated and
+ * zero-padded
+ * - task_lock() to ensure the operation is atomic and the name is
+ * fully updated.
*/
char comm[TASK_COMM_LEN];
@@ -1912,10 +1915,27 @@ static inline void set_task_comm(struct task_struct *tsk, const char *from)
__set_task_comm(tsk, from, false);
}
-extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
+/*
+ * - Why not use task_lock()?
+ * User space can randomly change their names anyway, so locking for readers
+ * doesn't make sense. For writers, locking is probably necessary, as a race
+ * condition could lead to long-term mixed results.
+ * The strscpy_pad() in __set_task_comm() can ensure that the task comm is
+ * always NUL-terminated and zero-padded. Therefore the race condition between
+ * reader and writer is not an issue.
+ *
+ * - Why not use strscpy_pad()?
+ * While strscpy_pad() prevents writing garbage past the NUL terminator, which
+ * is useful when using the task name as a key in a hash map, most use cases
+ * don't require this. Zero-padding might confuse users if it’s unnecessary,
+ * and not zeroing might even make it easier to expose bugs. If you need a
+ * zero-padded task name, please handle that explicitly at the call site.
+ *
+ * - ARRAY_SIZE() can help ensure that @buf is indeed an array.
+ */
#define get_task_comm(buf, tsk) ({ \
- BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
- __get_task_comm(buf, sizeof(buf), tsk); \
+ strscpy(buf, (tsk)->comm, ARRAY_SIZE(buf)); \
+ buf; \
})
#ifdef CONFIG_SMP
@@ -101,7 +101,7 @@ void get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk)
struct kthread *kthread = to_kthread(tsk);
if (!kthread || !kthread->full_name) {
- __get_task_comm(buf, buf_size, tsk);
+ strscpy(buf, tsk->comm, buf_size);
return;
}
We want to eliminate the use of __get_task_comm() for the following reasons: - The task_lock() is unnecessary Quoted from Linus [0]: : Since user space can randomly change their names anyway, using locking : was always wrong for readers (for writers it probably does make sense : to have some lock - although practically speaking nobody cares there : either, but at least for a writer some kind of race could have : long-term mixed results - The BUILD_BUG_ON() doesn't add any value The only requirement is to ensure that the destination buffer is a valid array. - Zeroing is not necessary in current use cases To avoid confusion, we should remove it. Moreover, not zeroing could potentially make it easier to uncover bugs. If the caller needs a zero-padded task name, it should be explicitly handled at the call site. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com [0] Link: https://lore.kernel.org/all/CAHk-=whWtUC-AjmGJveAETKOMeMFSTwKwu99v7+b6AyHMmaDFA@mail.gmail.com/ Suggested-by: Alejandro Colomar <alx@kernel.org> Link: https://lore.kernel.org/all/2jxak5v6dfxlpbxhpm3ey7oup4g2lnr3ueurfbosf5wdo65dk4@srb3hsk72zwq Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Matus Jokay <matus.jokay@stuba.sk> Cc: Alejandro Colomar <alx@kernel.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> --- fs/exec.c | 10 ---------- fs/proc/array.c | 2 +- include/linux/sched.h | 32 ++++++++++++++++++++++++++------ kernel/kthread.c | 2 +- 4 files changed, 28 insertions(+), 18 deletions(-)