properly support exec and wait with kernel pointers v2
Hi all, this series first cleans up the exec code and then adds proper kernel_execveat and kernel_wait callers instead of relying on the fact that the early init code and kernel threads implicitly run with the address limit set to KERNEL_DS. Note that the cleanup removes the compat execve(at) handlers entirely, as we can handle the compat difference very nicely in a unified codebase. x32 needs two hacky #defines for that for now, although those can go away if the x32 syscall rework from Brian gets merged. Changes since v1: - remove a pointless ifdef from get_user_arg_ptr - remove the need for a compat syscall handler for x32 Diffstat: arch/arm64/include/asm/unistd32.h |4 arch/mips/kernel/syscalls/syscall_n32.tbl |4 arch/mips/kernel/syscalls/syscall_o32.tbl |4 arch/parisc/kernel/syscalls/syscall.tbl|4 arch/powerpc/kernel/syscalls/syscall.tbl |4 arch/s390/kernel/syscalls/syscall.tbl |4 arch/sparc/kernel/syscalls.S |4 arch/x86/entry/syscall_x32.c |7 arch/x86/entry/syscalls/syscall_32.tbl |4 arch/x86/entry/syscalls/syscall_64.tbl |4 fs/exec.c | 248 - include/linux/binfmts.h| 10 include/linux/compat.h |7 include/linux/sched/task.h |1 include/uapi/asm-generic/unistd.h |4 init/main.c|5 kernel/exit.c | 16 + kernel/umh.c | 43 --- tools/include/uapi/asm-generic/unistd.h|4 tools/perf/arch/powerpc/entry/syscalls/syscall.tbl |4 tools/perf/arch/s390/entry/syscalls/syscall.tbl|4 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl |4 22 files changed, 170 insertions(+), 223 deletions(-)
Re: properly support exec and wait with kernel pointers
On Mon, Jun 15, 2020 at 3:00 PM Christoph Hellwig wrote: > > Hi all, > > this series first cleans up the exec code and then adds proper > kernel_execveat and kernel_wait callers instead of relying on the fact > that the early init code and kernel threads implicitly run with > the address limit set to KERNEL_DS. > > Note that the cleanup removes the compat execve(at) handlers (almost) > entirely, as we can handle the compat difference very nicely in a > unified codebase. The only exception is x86 where this would list the > handlers twice in the same syscall table due to the messed up x32 > design. I had to add an extra compat handler just for that case, but > maybe someone has a better idea. I looked at all the patches and I like it a lot. I replied with some suggestions for x32, but maybe I misunderstood what its problem is, as I don't see anything preventing us from having two entries in the x32 table pointing to the same function. Arnd
properly support exec and wait with kernel pointers
Hi all, this series first cleans up the exec code and then adds proper kernel_execveat and kernel_wait callers instead of relying on the fact that the early init code and kernel threads implicitly run with the address limit set to KERNEL_DS. Note that the cleanup removes the compat execve(at) handlers (almost) entirely, as we can handle the compat difference very nicely in a unified codebase. The only exception is x86 where this would list the handlers twice in the same syscall table due to the messed up x32 design. I had to add an extra compat handler just for that case, but maybe someone has a better idea.
