linux/arch/mips/kernel/binfmt_elfn32.c
Arnd Bergmann e2bb80d55d y2038: elfcore: Use __kernel_old_timeval for process times
We store elapsed time for a crashed process in struct elf_prstatus using
'timeval' structures. Once glibc starts using 64-bit time_t, this becomes
incompatible with the kernel's idea of timeval since the structure layout
no longer matches on 32-bit architectures.

This changes the definition of the elf_prstatus structure to use
__kernel_old_timeval instead, which is hardcoded to the currently used
binary layout. There is no risk of overflow in y2038 though, because
the time values are all relative times, and can store up to 68 years
of process elapsed time.

There is a risk of applications breaking at build time when they
use the new kernel headers and expect the type to be exactly 'timeval'
rather than a structure that has the same fields as before. Those
applications have to be modified to deal with 64-bit time_t anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15 14:38:29 +01:00

107 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Support for n32 Linux/MIPS ELF binaries.
* Author: Ralf Baechle (ralf@linux-mips.org)
*
* Copyright (C) 1999, 2001 Ralf Baechle
* Copyright (C) 1999, 2001 Silicon Graphics, Inc.
*
* Heavily inspired by the 32-bit Sparc compat code which is
* Copyright (C) 1995, 1996, 1997, 1998 David S. Miller (davem@redhat.com)
* Copyright (C) 1995, 1996, 1997, 1998 Jakub Jelinek (jj@ultra.linux.cz)
*/
#define ELF_ARCH EM_MIPS
#define ELF_CLASS ELFCLASS32
#ifdef __MIPSEB__
#define ELF_DATA ELFDATA2MSB;
#else /* __MIPSEL__ */
#define ELF_DATA ELFDATA2LSB;
#endif
/* ELF register definitions */
#define ELF_NGREG 45
#define ELF_NFPREG 33
typedef unsigned long elf_greg_t;
typedef elf_greg_t elf_gregset_t[ELF_NGREG];
typedef double elf_fpreg_t;
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
#define elf_check_arch elfn32_check_arch
#define TASK32_SIZE 0x7fff8000UL
#undef ELF_ET_DYN_BASE
#define ELF_ET_DYN_BASE (TASK32_SIZE / 3 * 2)
#include <asm/processor.h>
#include <linux/elfcore.h>
#include <linux/compat.h>
#include <linux/math64.h>
#define elf_prstatus elf_prstatus32
struct elf_prstatus32
{
struct elf_siginfo pr_info; /* Info associated with signal */
short pr_cursig; /* Current signal */
unsigned int pr_sigpend; /* Set of pending signals */
unsigned int pr_sighold; /* Set of held signals */
pid_t pr_pid;
pid_t pr_ppid;
pid_t pr_pgrp;
pid_t pr_sid;
struct old_timeval32 pr_utime; /* User time */
struct old_timeval32 pr_stime; /* System time */
struct old_timeval32 pr_cutime;/* Cumulative user time */
struct old_timeval32 pr_cstime;/* Cumulative system time */
elf_gregset_t pr_reg; /* GP registers */
int pr_fpvalid; /* True if math co-processor being used. */
};
#define elf_prpsinfo elf_prpsinfo32
struct elf_prpsinfo32
{
char pr_state; /* numeric process state */
char pr_sname; /* char for pr_state */
char pr_zomb; /* zombie */
char pr_nice; /* nice val */
unsigned int 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 */
char pr_fname[16]; /* filename of executable */
char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
};
#define elf_caddr_t u32
#define init_elf_binfmt init_elfn32_binfmt
#define jiffies_to_timeval jiffies_to_old_timeval32
static __inline__ void
jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value)
{
/*
* Convert jiffies to nanoseconds and separate with
* one divide.
*/
u64 nsec = (u64)jiffies * TICK_NSEC;
u32 rem;
value->tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
value->tv_usec = rem / NSEC_PER_USEC;
}
#define ELF_CORE_EFLAGS EF_MIPS_ABI2
#undef TASK_SIZE
#define TASK_SIZE TASK_SIZE32
#undef ns_to_kernel_old_timeval
#define ns_to_kernel_old_timeval ns_to_old_timeval32
#include "../../../fs/binfmt_elf.c"