lkml.org 
[lkml]   [2018]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH][RFC] [powerpc] arch_ptrace() uses of access_ok() are pointless
On Mon, May 28, 2018 at 12:34 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> make it use copy_{from,to}_user(), rather than access_ok() +
> __copy_...
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> arch/powerpc/kernel/ptrace.c | 22 +++++++---------------
> 1 file changed, 7 insertions(+), 15 deletions(-)
>
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index d23cf632edf0..d8b0fd2fa3aa 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -3081,27 +3081,19 @@ long arch_ptrace(struct task_struct *child, long request,
> #endif /* CONFIG_HAVE_HW_BREAKPOINT */
> #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
>
> - if (!access_ok(VERIFY_WRITE, datavp,
> - sizeof(struct ppc_debug_info)))
> + if (unlikely(copy_to_user(datavp, &dbginfo,
> + sizeof(struct ppc_debug_info)))


Maybe this is just an RFC, but:

CALL ../arch/powerpc/kernel/systbl_chk.sh
../arch/powerpc/kernel/ptrace.c: In function ‘arch_ptrace’:
../arch/powerpc/kernel/ptrace.c:3086:4: error: expected ‘)’ before ‘return’
return -EFAULT;
^~~~~~

Missing closing parenthesis.

> return -EFAULT;
> - ret = __copy_to_user(datavp, &dbginfo,
> - sizeof(struct ppc_debug_info)) ?
> - -EFAULT : 0;
> - break;
> + return 0;
> }
>
> case PPC_PTRACE_SETHWDEBUG: {
> struct ppc_hw_breakpoint bp_info;
>
> - if (!access_ok(VERIFY_READ, datavp,
> - sizeof(struct ppc_hw_breakpoint)))
> - return -EFAULT;
> - ret = __copy_from_user(&bp_info, datavp,
> - sizeof(struct ppc_hw_breakpoint)) ?
> - -EFAULT : 0;
> - if (!ret)
> - ret = ppc_set_hwdebug(child, &bp_info);
> - break;
> + if (unlikely(copy_from_user(&bp_info, datavp,
> + sizeof(struct ppc_hw_breakpoint)))
> + return -EFAULT;
> + return ppc_set_hwdebug(child, &bp_info);
> }
>
> case PPC_PTRACE_DELHWDEBUG: {
> --
> 2.11.0
>

\
 
 \ /
  Last update: 2018-05-28 21:26    [W:0.045 / U:0.400 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site