Re: [PATCH] ilp32: fix {GET,SET}SIGMASK request for ptrace

[Yury Norov]

Hi Zhou,

Thank you for the patch. The idea is ok, but patch format got broken
for some reason. Could you re-send it?

Yury.

On Mon, Jun 27, 2016 at 12:49:05PM +0800, zhouchengming wrote:
> atus: RO
> Content-Length: 4732
> Lines: 181
> 
> The function compat_ptrace_request(used by ilp32) don't handle
> {GET,SET}SIGMASK request, so it will be handled by ptrace_request.
> But it's wrong because the compat_sigset_t of ilp32 differs from
> the sigset_t of aarch64. The patch fixes it.
> 
> Signed-off-by: Zhou Chengming <zhouchengming1@xxxxxxxxxx>
> ---
>  arch/arm64/include/asm/signal_ilp32.h |   22 ++++++++++++
>  arch/arm64/kernel/ptrace.c            |   62
> +++++++++++++++++++++++++++++++++

Here -  unneeded line break

>  arch/arm64/kernel/signal_ilp32.c      |   23 +------------
>  3 files changed, 85 insertions(+), 22 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/signal_ilp32.h
> b/arch/arm64/include/asm/signal_ilp32.h

and here

> index 30eff23..ed52607 100644
> --- a/arch/arm64/include/asm/signal_ilp32.h
> +++ b/arch/arm64/include/asm/signal_ilp32.h
> @@ -21,6 +21,28 @@
>  int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set,
>  			  struct pt_regs *regs);
> 
> +static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
> +{
> +	compat_sigset_t cset;
> +
> +	cset.sig[0] = set->sig[0] & 0xffffffffull;
> +	cset.sig[1] = set->sig[0] >> 32;
> +
> +	return copy_to_user(uset, &cset, sizeof(*uset));
> +}
> +
> +static inline int get_sigset_t(sigset_t *set,
> +			       const compat_sigset_t __user *uset)
> +{
> +	compat_sigset_t s32;
> +
> +	if (copy_from_user(&s32, uset, sizeof(*uset)))
> +		return -EFAULT;
> +
> +	set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
> +	return 0;
> +}
> +
>  #else
> 
>  static inline int ilp32_setup_rt_frame(int usig, struct ksignal *ksig,
> sigset_t *set,

and here

> diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
> index a861105..8d4cad1 100644
> --- a/arch/arm64/kernel/ptrace.c
> +++ b/arch/arm64/kernel/ptrace.c
> @@ -44,6 +44,7 @@
>  #include <asm/syscall.h>
>  #include <asm/traps.h>
>  #include <asm/system_misc.h>
> +#include <asm/signal_ilp32.h>
> 
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/syscalls.h>
> @@ -1231,12 +1232,73 @@ COMPAT_SYSCALL_DEFINE4(aarch32_ptrace,
> compat_long_t, request, compat_long_t, pi

and later on the patch

> 
>  #endif /* CONFIG_AARCH32_EL0 */
> 
> +#ifdef CONFIG_ARM64_ILP32
> +
> +static int compat_ilp32_ptrace(struct task_struct *child, compat_long_t
> request,
> +			compat_ulong_t addr, compat_ulong_t data)
> +{
> +	compat_ulong_t __user *datap = compat_ptr(data);
> +	int ret;
> +
> +	switch (request) {
> +	case PTRACE_GETSIGMASK:
> +		if (addr != sizeof(compat_sigset_t)) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
> +		if (put_sigset_t((compat_sigset_t __user *)datap, &child->blocked))
> +			ret = -EFAULT;
> +		else
> +			ret = 0;
> +		break;
> +
> +	case PTRACE_SETSIGMASK: {
> +		sigset_t new_set;
> +		if (addr != sizeof(compat_sigset_t)) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
> +		if (get_sigset_t(&new_set, (compat_sigset_t __user *)datap)) {
> +			ret = -EFAULT;
> +			break;
> +		}
> +
> +		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
> +
> +		/*
> +		 * Every thread does recalc_sigpending() after resume, so
> +		 * retarget_shared_pending() and recalc_sigpending() are not
> +		 * called here.
> +		 */
> +		spin_lock_irq(&child->sighand->siglock);
> +		child->blocked = new_set;
> +		spin_unlock_irq(&child->sighand->siglock);
> +
> +		ret = 0;
> +		break;
> +	}
> +
> +	default:
> +		ret = compat_ptrace_request(child, request, addr, data);
> +	}
> +
> +	return ret;
> +}
> +
> +#endif /* CONFIG_ARM64_ILP32 */
> +
>  #ifdef CONFIG_COMPAT
> 
>  long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
>  			compat_ulong_t caddr, compat_ulong_t cdata)
>  {
> +#ifdef CONFIG_ARM64_ILP32
> +	return compat_ilp32_ptrace(child, request, caddr, cdata);
> +#else
>  	return compat_ptrace_request(child, request, caddr, cdata);
> +#endif
>  }
> 
>  #endif /* CONFIG_COMPAT */
> diff --git a/arch/arm64/kernel/signal_ilp32.c
> b/arch/arm64/kernel/signal_ilp32.c
> index 8ca64b9..3ef2749 100644
> --- a/arch/arm64/kernel/signal_ilp32.c
> +++ b/arch/arm64/kernel/signal_ilp32.c
> @@ -28,6 +28,7 @@
>  #include <asm/fpsimd.h>
>  #include <asm/signal32_common.h>
>  #include <asm/signal_common.h>
> +#include <asm/signal_ilp32.h>
>  #include <asm/uaccess.h>
>  #include <asm/unistd.h>
>  #include <asm/ucontext.h>
> @@ -58,28 +59,6 @@ struct ilp32_rt_sigframe {
>  	struct ilp32_sigframe sig;
>  };
> 
> -static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
> -{
> -	compat_sigset_t cset;
> -
> -	cset.sig[0] = set->sig[0] & 0xffffffffull;
> -	cset.sig[1] = set->sig[0] >> 32;
> -
> -	return copy_to_user(uset, &cset, sizeof(*uset));
> -}
> -
> -static inline int get_sigset_t(sigset_t *set,
> -                               const compat_sigset_t __user *uset)
> -{
> -	compat_sigset_t s32;
> -
> -	if (copy_from_user(&s32, uset, sizeof(*uset)))
> -		return -EFAULT;
> -
> -	set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
> -	return 0;
> -}
> -
>  static int restore_ilp32_sigframe(struct pt_regs *regs,
>                              struct