linux-stable/include/linux/elfcore.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

154 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ELFCORE_H
#define _LINUX_ELFCORE_H
#include <linux/user.h>
#include <linux/bug.h>
#include <linux/sched/task_stack.h>
#include <linux/types.h>
#include <linux/signal.h>
#include <linux/time.h>
#include <linux/ptrace.h>
#include <linux/fs.h>
#include <linux/elf.h>
struct coredump_params;
struct elf_siginfo
{
int si_signo; /* signal number */
int si_code; /* extra code */
int si_errno; /* errno */
};
/*
* Definitions to generate Intel SVR4-like core files.
* These mostly have the same names as the SVR4 types with "elf_"
* tacked on the front to prevent clashes with linux definitions,
* and the typedef forms have been avoided. This is mostly like
* the SVR4 structure, but more Linuxy, with things that Linux does
* not support and which gdb doesn't really use excluded.
*/
struct elf_prstatus_common
{
struct elf_siginfo pr_info; /* Info associated with signal */
short pr_cursig; /* Current signal */
unsigned long pr_sigpend; /* Set of pending signals */
unsigned long pr_sighold; /* Set of held signals */
pid_t pr_pid;
pid_t pr_ppid;
pid_t pr_pgrp;
pid_t pr_sid;
struct __kernel_old_timeval pr_utime; /* User time */
struct __kernel_old_timeval pr_stime; /* System time */
struct __kernel_old_timeval pr_cutime; /* Cumulative user time */
struct __kernel_old_timeval pr_cstime; /* Cumulative system time */
};
struct elf_prstatus
{
struct elf_prstatus_common common;
elf_gregset_t pr_reg; /* GP registers */
int pr_fpvalid; /* True if math co-processor being used. */
};
#define ELF_PRARGSZ (80) /* Number of chars for args */
struct elf_prpsinfo
{
char pr_state; /* numeric process state */
char pr_sname; /* char for pr_state */
char pr_zomb; /* zombie */
char pr_nice; /* nice val */
unsigned long pr_flag; /* flags */
__kernel_uid_t pr_uid;
__kernel_gid_t pr_gid;
pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid;
/* Lots missing */
/*
* 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]; /* filename of executable */
char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
};
static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
{
#ifdef ELF_CORE_COPY_REGS
ELF_CORE_COPY_REGS((*elfregs), regs)
#else
BUG_ON(sizeof(*elfregs) != sizeof(*regs));
*(struct pt_regs *)elfregs = *regs;
#endif
}
static inline void elf_core_copy_kernel_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
{
#ifdef ELF_CORE_COPY_KERNEL_REGS
ELF_CORE_COPY_KERNEL_REGS((*elfregs), regs);
#else
elf_core_copy_regs(elfregs, regs);
#endif
}
static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
{
#if defined (ELF_CORE_COPY_TASK_REGS)
return ELF_CORE_COPY_TASK_REGS(t, elfregs);
#elif defined (task_pt_regs)
elf_core_copy_regs(elfregs, task_pt_regs(t));
#endif
return 0;
}
extern int dump_fpu (struct pt_regs *, elf_fpregset_t *);
static inline int elf_core_copy_task_fpregs(struct task_struct *t, struct pt_regs *regs, elf_fpregset_t *fpu)
{
#ifdef ELF_CORE_COPY_FPREGS
return ELF_CORE_COPY_FPREGS(t, fpu);
#else
return dump_fpu(regs, fpu);
#endif
}
#if (defined(CONFIG_UML) && defined(CONFIG_X86_32)) || defined(CONFIG_IA64)
/*
* These functions parameterize elf_core_dump in fs/binfmt_elf.c to write out
* extra segments containing the gate DSO contents. Dumping its
* contents makes post-mortem fully interpretable later without matching up
* the same kernel and hardware config to see what PC values meant.
* Dumping its extra ELF program headers includes all the other information
* a debugger needs to easily find how the gate DSO was being used.
*/
extern Elf_Half elf_core_extra_phdrs(void);
extern int
elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset);
extern int
elf_core_write_extra_data(struct coredump_params *cprm);
extern size_t elf_core_extra_data_size(void);
#else
static inline Elf_Half elf_core_extra_phdrs(void)
{
return 0;
}
static inline int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
{
return 1;
}
static inline int elf_core_write_extra_data(struct coredump_params *cprm)
{
return 1;
}
static inline size_t elf_core_extra_data_size(void)
{
return 0;
}
#endif
#endif /* _LINUX_ELFCORE_H */