linux-dev/arch/mips/kernel/binfmt_elfn32.c, branch linus/master

mips compat: switch to compat_binfmt_elf.c

2021-01-06T13:42:49Z

Like amd64, mips has two 32bit ABIs - o32 and n32. Unlike amd64, it does not use compat_binfmt_elf.c for either of those; each of those ABIs has a binfmt handler of its own, both very similar to fs/compat_binfmt_elf.c. And the same technics as we use on amd64 can be used to make fs/compat_binfmt_elf.c handle both. * merge elfo32_check_arch() with elfn32_check_arch(), make that serve as compat_elf_check_arch(). Note that SET_PERSONALITY2() is already the same for all ABI variants - it looks at the elf header to choose the flags to set. * add asm/elfcore-compat.h, using the bigger (n32) variant of elf32_prstatus as compat_elf_prstatus there. * make PRSTATUS_SIZE() and SET_PR_FPVALID() choose the right layout, same as done for amd64. test_thread_flag(TIF_32BIT_REGS) is used as the predicate. Voila - we are rid of binfmt_elf{n,o}32.c; fs/compat_binfmt_elf.c is used, same as for all other ELF-supporting 64bit architectures that need 32bit compat. Signed-off-by: Al Viro

mips: don't bother with ELF_CORE_EFLAGS

2021-01-06T13:42:48Z

mips coredumps are regset-based, so ELF_CORE_EFLAGS is not used at all - user_..._view.e_flags is. Signed-off-by: Al Viro

mips compat: don't bother with ELF_ET_DYN_BASE

2021-01-06T13:42:47Z

normal mips one is just fine - it's only used after we'd done SET_PERSONALITY2() and by that point TASK_SIZE will yield the right value Signed-off-by: Al Viro

mips: kill unused definitions in binfmt_elf[on]32.c

2021-01-06T13:42:46Z

elf_caddr_t: unused since 2002 jiffies_to_timeval: unused since 2015 TASK_SIZE: used only downstream of SET_PERSONALITY2(), and after that point the normal definition results in TASK_SIZE32 just fine. Signed-off-by: Al Viro

mips binfmt_elf*32.c: use elfcore-compat.h

2021-01-06T13:42:45Z

... rather than duplicating declarations from it. Signed-off-by: Al Viro

Merge remote-tracking branch 'mips/mips-fixes' into work.elf-compat

2021-01-06T13:41:59Z

backmerge of mips compat coredump fix

elf_prstatus: collect the common part (everything before pr_reg) into a struct

2021-01-06T13:38:29Z

Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating the beginning of compat_elf_prstatus, take these fields into a separate structure (compat_elf_prstatus_common), so that it could be reused. Due to the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we need the same shape change done to native struct elf_prstatus, gathering the fields prior to pr_reg into a new structure (struct elf_prstatus_common). Fortunately, offset of pr_reg is always a multiple of 16 with no padding right before it, so it's possible to turn all the stuff prior to it into a single member without disturbing the layout. [build fix from Geert Uytterhoeven folded in] Signed-off-by: Al Viro

MIPS: Fix malformed NT_FILE and NT_SIGINFO in 32bit coredumps

2020-12-28T22:26:17Z

Patches that introduced NT_FILE and NT_SIGINFO notes back in 2012 had taken care of native (fs/binfmt_elf.c) and compat (fs/compat_binfmt_elf.c) coredumps; unfortunately, compat on mips (which does not go through the usual compat_binfmt_elf.c) had not been noticed. As the result, both N32 and O32 coredumps on 64bit mips kernels have those sections malformed enough to confuse the living hell out of all gdb and readelf versions (up to and including the tip of binutils-gdb.git). Longer term solution is to make both O32 and N32 compat use the regular compat_binfmt_elf.c, but that's too much for backports. The minimal solution is to do in arch/mips/kernel/binfmt_elf[on]32.c the same thing those patches have done in fs/compat_binfmt_elf.c Cc: stable@kernel.org # v3.7+ Signed-off-by: Al Viro Signed-off-by: Thomas Bogendoerfer

y2038: elfcore: Use __kernel_old_timeval for process times

2019-11-15T13:38:29Z

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

y2038: globally rename compat_time to old_time32

2018-08-27T12:48:48Z

Christoph Hellwig suggested a slightly different path for handling backwards compatibility with the 32-bit time_t based system calls: Rather than simply reusing the compat_sys_* entry points on 32-bit architectures unchanged, we get rid of those entry points and the compat_time types by renaming them to something that makes more sense on 32-bit architectures (which don't have a compat mode otherwise), and then share the entry points under the new name with the 64-bit architectures that use them for implementing the compatibility. The following types and interfaces are renamed here, and moved from linux/compat_time.h to linux/time32.h: old new --- --- compat_time_t old_time32_t struct compat_timeval struct old_timeval32 struct compat_timespec struct old_timespec32 struct compat_itimerspec struct old_itimerspec32 ns_to_compat_timeval() ns_to_old_timeval32() get_compat_itimerspec64() get_old_itimerspec32() put_compat_itimerspec64() put_old_itimerspec32() compat_get_timespec64() get_old_timespec32() compat_put_timespec64() put_old_timespec32() As we already have aliases in place, this patch addresses only the instances that are relevant to the system call interface in particular, not those that occur in device drivers and other modules. Those will get handled separately, while providing the 64-bit version of the respective interfaces. I'm not renaming the timex, rusage and itimerval structures, as we are still debating what the new interface will look like, and whether we will need a replacement at all. This also doesn't change the names of the syscall entry points, which can be done more easily when we actually switch over the 32-bit architectures to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix. Suggested-by: Christoph Hellwig Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/ Signed-off-by: Arnd Bergmann