| Message ID | 20180527223403.GT30522@ZenIV.linux.org.uk (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,powerpc] arch_ptrace() uses of access_ok() are pointless | expand |
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 >
> 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; > ^~~~~~ and the same a few lines later. What's more, those 'unlikely' are pointless there. Fixed variant follows; only build-tested, though. 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..f557322621e0 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 (copy_to_user(datavp, &dbginfo, + sizeof(struct ppc_debug_info))) 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 (copy_from_user(&bp_info, datavp, + sizeof(struct ppc_hw_breakpoint))) + return -EFAULT; + return ppc_set_hwdebug(child, &bp_info); } case PPC_PTRACE_DELHWDEBUG: {
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))) 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: {
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(-)