linux-next/include/linux/elfcore-compat.h
Yafang Shao 95af469c4f fs/binfmt_elf: replace open-coded string copy with get_task_comm
It is better to use get_task_comm() instead of the open coded string
copy as we do in other places.

struct elf_prpsinfo is used to dump the task information in userspace
coredump or kernel vmcore.  Below is the verification of vmcore,

  crash> ps
     PID    PPID  CPU       TASK        ST  %MEM     VSZ    RSS  COMM
        0      0   0  ffffffff9d21a940  RU   0.0       0      0  [swapper/0]
  >     0      0   1  ffffa09e40f85e80  RU   0.0       0      0  [swapper/1]
  >     0      0   2  ffffa09e40f81f80  RU   0.0       0      0  [swapper/2]
  >     0      0   3  ffffa09e40f83f00  RU   0.0       0      0  [swapper/3]
  >     0      0   4  ffffa09e40f80000  RU   0.0       0      0  [swapper/4]
  >     0      0   5  ffffa09e40f89f80  RU   0.0       0      0  [swapper/5]
        0      0   6  ffffa09e40f8bf00  RU   0.0       0      0  [swapper/6]
  >     0      0   7  ffffa09e40f88000  RU   0.0       0      0  [swapper/7]
  >     0      0   8  ffffa09e40f8de80  RU   0.0       0      0  [swapper/8]
  >     0      0   9  ffffa09e40f95e80  RU   0.0       0      0  [swapper/9]
  >     0      0  10  ffffa09e40f91f80  RU   0.0       0      0  [swapper/10]
  >     0      0  11  ffffa09e40f93f00  RU   0.0       0      0  [swapper/11]
  >     0      0  12  ffffa09e40f90000  RU   0.0       0      0  [swapper/12]
  >     0      0  13  ffffa09e40f9bf00  RU   0.0       0      0  [swapper/13]
  >     0      0  14  ffffa09e40f98000  RU   0.0       0      0  [swapper/14]
  >     0      0  15  ffffa09e40f9de80  RU   0.0       0      0  [swapper/15]

It works well as expected.

Some comments are added to explain why we use the hard-coded 16.

Link: https://lkml.kernel.org/r/20211120112738.45980-5-laoar.shao@gmail.com
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-20 08:52:53 +02:00

67 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ELFCORE_COMPAT_H
#define _LINUX_ELFCORE_COMPAT_H
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/compat.h>
/*
* Make sure these layouts match the linux/elfcore.h native definitions.
*/
struct compat_elf_siginfo
{
compat_int_t si_signo;
compat_int_t si_code;
compat_int_t si_errno;
};
struct compat_elf_prstatus_common
{
struct compat_elf_siginfo pr_info;
short pr_cursig;
compat_ulong_t pr_sigpend;
compat_ulong_t pr_sighold;
compat_pid_t pr_pid;
compat_pid_t pr_ppid;
compat_pid_t pr_pgrp;
compat_pid_t pr_sid;
struct old_timeval32 pr_utime;
struct old_timeval32 pr_stime;
struct old_timeval32 pr_cutime;
struct old_timeval32 pr_cstime;
};
struct compat_elf_prpsinfo
{
char pr_state;
char pr_sname;
char pr_zomb;
char pr_nice;
compat_ulong_t pr_flag;
__compat_uid_t pr_uid;
__compat_gid_t pr_gid;
compat_pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid;
/*
* The hard-coded 16 is derived from TASK_COMM_LEN, but it can't be
* changed as it is exposed to userspace. We'd better make it hard-coded
* here.
*/
char pr_fname[16];
char pr_psargs[ELF_PRARGSZ];
};
#ifdef CONFIG_ARCH_HAS_ELFCORE_COMPAT
#include <asm/elfcore-compat.h>
#endif
struct compat_elf_prstatus
{
struct compat_elf_prstatus_common common;
compat_elf_gregset_t pr_reg;
compat_int_t pr_fpvalid;
};
#endif /* _LINUX_ELFCORE_COMPAT_H */