Re: [Xen-devel] [PATCH v3 1/3] syscalls, x86 Expose arch_prctl on x86-32.
On Fri, Sep 16, 2016 at 12:50 AM, Thomas Gleixner wrote: > On Thu, 15 Sep 2016, Kyle Huey wrote: > > First of all, please add a cover letter [PATCH 0/N] to your patch series > and send it with something which provides proper mail threading. > See: git-send-email, quilt I did ... seems like using git-send-email with --cc-cmd=scripts/get_maintainer.pl is not a good idea since people get CCd to some parts of the thread and not others. https://lkml.org/lkml/2016/9/15/811 >> arch_prctl is currently 64-bit only. Wire it up for 32-bits, as a no-op for >> now. Rename the second arg to a more generic name. > > This changelog is useless. > > - it does not provide any rationale for this change, i.e. why this is > required. Just because its 64bit only is not a reason. > > - "Rename the second arg to a more generic name" does not give > any useful information. > > Misleading information is worse than no information. > > Further your patch does 5 things at once. It wants to be split into parts: > > 1) Rename do_arch_prctl() and change the argument name, > >> -long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) >> +long do_arch_prctl_64(struct task_struct *task, int code, unsigned long >> arg2) > > 2) Provide do_arch_prctl_common() and hook it up to the arch_prctl syscall > >> -long sys_arch_prctl(int code, unsigned long addr) >> +SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) >> { >> - return do_arch_prctl(current, code, addr); >> + long ret; >> + >> + ret = do_arch_prctl_64(current, code, arg2); >> + if (ret == -EINVAL) >> + ret = do_arch_prctl_common(current, code, arg2); >> + >> + return ret; >> } > > 3) Implement the compat version Ok. - Kyle ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v3 1/3] syscalls, x86 Expose arch_prctl on x86-32.
On Thu, 15 Sep 2016, Kyle Huey wrote: First of all, please add a cover letter [PATCH 0/N] to your patch series and send it with something which provides proper mail threading. See: git-send-email, quilt > arch_prctl is currently 64-bit only. Wire it up for 32-bits, as a no-op for > now. Rename the second arg to a more generic name. This changelog is useless. - it does not provide any rationale for this change, i.e. why this is required. Just because its 64bit only is not a reason. - "Rename the second arg to a more generic name" does not give any useful information. Misleading information is worse than no information. Further your patch does 5 things at once. It wants to be split into parts: 1) Rename do_arch_prctl() and change the argument name, > -long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) > +long do_arch_prctl_64(struct task_struct *task, int code, unsigned long arg2) 2) Provide do_arch_prctl_common() and hook it up to the arch_prctl syscall > -long sys_arch_prctl(int code, unsigned long addr) > +SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) > { > - return do_arch_prctl(current, code, addr); > + long ret; > + > + ret = do_arch_prctl_64(current, code, arg2); > + if (ret == -EINVAL) > + ret = do_arch_prctl_common(current, code, arg2); > + > + return ret; > } 3) Implement the compat version Thanks, tflx ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v3 1/3] syscalls, x86 Expose arch_prctl on x86-32.
On Thu, Sep 15, 2016 at 4:33 PM, Kyle Huey wrote: > arch_prctl is currently 64-bit only. Wire it up for 32-bits, as a no-op for > now. Rename the second arg to a more generic name. > > Signed-off-by: Kyle Huey > --- > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > arch/x86/include/asm/proto.h | 5 - > arch/x86/kernel/process.c | 10 ++ > arch/x86/kernel/process_64.c | 33 + > arch/x86/kernel/ptrace.c | 8 > arch/x86/um/Makefile | 2 +- > arch/x86/um/syscalls_32.c | 7 +++ > arch/x86/um/syscalls_64.c | 4 ++-- > include/linux/compat.h | 2 ++ > 9 files changed, 52 insertions(+), 20 deletions(-) > create mode 100644 arch/x86/um/syscalls_32.c > > diff --git a/arch/x86/entry/syscalls/syscall_32.tbl > b/arch/x86/entry/syscalls/syscall_32.tbl > index f848572..666fa61 100644 > --- a/arch/x86/entry/syscalls/syscall_32.tbl > +++ b/arch/x86/entry/syscalls/syscall_32.tbl > @@ -386,3 +386,4 @@ > 377i386copy_file_range sys_copy_file_range > 378i386preadv2 sys_preadv2 > compat_sys_preadv2 > 379i386pwritev2sys_pwritev2 > compat_sys_pwritev2 > +380i386arch_prctl compat_sys_arch_prctl > compat_sys_arch_prctl Let's call this sys_arch_prctl_32, even if it's unconventional. See below. > diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h > index 9b9b30b..f0e86aa 100644 > --- a/arch/x86/include/asm/proto.h > +++ b/arch/x86/include/asm/proto.h > @@ -30,6 +30,9 @@ void x86_report_nx(void); > > extern int reboot_force; > > -long do_arch_prctl(struct task_struct *task, int code, unsigned long addr); > +long do_arch_prctl_common(struct task_struct *task, int code, unsigned long > addr); > +#ifdef CONFIG_X86_64 > +long do_arch_prctl_64(struct task_struct *task, int code, unsigned long > addr); > +#endif > > #endif /* _ASM_X86_PROTO_H */ > diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c > index 62c0b0e..1421451 100644 > --- a/arch/x86/kernel/process.c > +++ b/arch/x86/kernel/process.c > @@ -567,3 +567,13 @@ unsigned long get_wchan(struct task_struct *p) > } while (count++ < 16 && p->state != TASK_RUNNING); > return 0; > } > + > +long do_arch_prctl_common(struct task_struct *task, int code, unsigned long > arg2) > +{ > + return -EINVAL; > +} > + > +asmlinkage long compat_sys_arch_prctl(int code, unsigned long arg2) I believe you mean COMPAT_SYSCALL_DEFINE2 here. But I see what you're doing here. Could you instead do: #if defined(CONFIG_IA32_EMULATION) || defined(CONFIG_X86_32) #ifdef CONFIG_X86_32 COMPAT_SYSCALL_DEFINE2(...) #else SYSCALL_DEFINE2(...) #endif ... body here ... #endif and name the thing do_arch_prctl_32? It's too bad we don't have a SYSCALL_DEFINE_32 macro. But you could add one... > diff --git a/arch/x86/um/syscalls_32.c b/arch/x86/um/syscalls_32.c > new file mode 100644 > index 000..c6812c1 > --- /dev/null > +++ b/arch/x86/um/syscalls_32.c > @@ -0,0 +1,7 @@ > +#include > +#include > + > +long compat_sys_arch_prctl(int code, unsigned long arg2) COMPAT_SYSCALL_DEFINE2 Also, does this really need a new file? > -long sys_arch_prctl(int code, unsigned long addr) > +long sys_arch_prctl(int code, unsigned long arg2) SYSCALL_DEFINE2 ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
[Xen-devel] [PATCH v3 1/3] syscalls, x86 Expose arch_prctl on x86-32.
arch_prctl is currently 64-bit only. Wire it up for 32-bits, as a no-op for now. Rename the second arg to a more generic name. Signed-off-by: Kyle Huey --- arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/include/asm/proto.h | 5 - arch/x86/kernel/process.c | 10 ++ arch/x86/kernel/process_64.c | 33 + arch/x86/kernel/ptrace.c | 8 arch/x86/um/Makefile | 2 +- arch/x86/um/syscalls_32.c | 7 +++ arch/x86/um/syscalls_64.c | 4 ++-- include/linux/compat.h | 2 ++ 9 files changed, 52 insertions(+), 20 deletions(-) create mode 100644 arch/x86/um/syscalls_32.c diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index f848572..666fa61 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -386,3 +386,4 @@ 377i386copy_file_range sys_copy_file_range 378i386preadv2 sys_preadv2 compat_sys_preadv2 379i386pwritev2sys_pwritev2 compat_sys_pwritev2 +380i386arch_prctl compat_sys_arch_prctl compat_sys_arch_prctl diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h index 9b9b30b..f0e86aa 100644 --- a/arch/x86/include/asm/proto.h +++ b/arch/x86/include/asm/proto.h @@ -30,6 +30,9 @@ void x86_report_nx(void); extern int reboot_force; -long do_arch_prctl(struct task_struct *task, int code, unsigned long addr); +long do_arch_prctl_common(struct task_struct *task, int code, unsigned long addr); +#ifdef CONFIG_X86_64 +long do_arch_prctl_64(struct task_struct *task, int code, unsigned long addr); +#endif #endif /* _ASM_X86_PROTO_H */ diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 62c0b0e..1421451 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -567,3 +567,13 @@ unsigned long get_wchan(struct task_struct *p) } while (count++ < 16 && p->state != TASK_RUNNING); return 0; } + +long do_arch_prctl_common(struct task_struct *task, int code, unsigned long arg2) +{ + return -EINVAL; +} + +asmlinkage long compat_sys_arch_prctl(int code, unsigned long arg2) +{ + return do_arch_prctl_common(current, code, arg2); +} diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 63236d8..0e44608 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -196,7 +197,7 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp, (struct user_desc __user *)tls, 0); else #endif - err = do_arch_prctl(p, ARCH_SET_FS, tls); + err = do_arch_prctl_64(p, ARCH_SET_FS, tls); if (err) goto out; } @@ -524,7 +525,7 @@ void set_personality_ia32(bool x32) } EXPORT_SYMBOL_GPL(set_personality_ia32); -long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) +long do_arch_prctl_64(struct task_struct *task, int code, unsigned long arg2) { int ret = 0; int doit = task == current; @@ -532,48 +533,50 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) switch (code) { case ARCH_SET_GS: - if (addr >= TASK_SIZE_MAX) + if (arg2 >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.gsindex = 0; - task->thread.gsbase = addr; + task->thread.gsbase = arg2; if (doit) { load_gs_index(0); - ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr); + ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, arg2); } put_cpu(); break; case ARCH_SET_FS: /* Not strictly needed for fs, but do it for symmetry with gs */ - if (addr >= TASK_SIZE_MAX) + if (arg2 >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.fsindex = 0; - task->thread.fsbase = addr; + task->thread.fsbase = arg2; if (doit) { /* set the selector to 0 to not confuse __switch_to */ loadsegment(fs, 0); - ret = wrmsrl_safe(MSR_FS_BASE, addr); + ret = wrmsrl_safe(MSR_FS_BASE, arg2); } put_cpu(); break; case ARCH_GET_FS: { unsigned long base; + if (doit) rdmsrl(MSR_FS_BASE