| Message ID | c7e45416cc911290efb5ad669f4a45bdc5678f69.camel@perches.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | new checkpatch flexible array test ? (was Re: [PATCH v4 12/14] gunyah: rsc_mgr: Add RPC for console services) | expand |
On Sun, Oct 02, 2022 at 06:46:30PM -0700, Joe Perches wrote: > On Fri, 2022-09-30 at 14:22 +0200, Greg Kroah-Hartman wrote: > > On Wed, Sep 28, 2022 at 12:56:31PM -0700, Elliot Berman wrote: > > > Gunyah resource manager defines a simple API for virtual machine log > > > sharing with the console service. > [] > > > diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h > [] > > > +struct gh_rm_notif_vm_console_chars { > > > + u16 vmid; > > > + u16 num_bytes; > > > + u8 bytes[0]; > > > > Please do not use [0] for new structures, otherwise we will just have to > > fix them up again as we are trying to get rid of all of these from the > > kernel. Just use "bytes[];" instead. > > Maybe a checkpatch addition like: > --- > scripts/checkpatch.pl | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > index 2737e4ced5745..187ed84c1f80a 100755 > --- a/scripts/checkpatch.pl > +++ b/scripts/checkpatch.pl > @@ -3948,6 +3948,17 @@ sub process { > } > } > > +# check for zero length array declarations in likely structs > + if ($line =~ /^\+\t($Declare\s*$Ident)\s*\[\s*0\s*\]\s*;\s*$/ && > + defined $lines[$linenr] && > + $lines[$linenr] =~ /^[\+ ]\}\s*(?:__\w+\s*(?:$balanced_parens)?)\s*;\s*$/) { > + if (WARN("FLEXIBLE_ARRAY_ZERO", > + "Prefer flexible length array declarations with [] over [0]\n" . $herecurr) && > + $fix) { > + $fixed[$fixlinenr] =~ s/\[\s*0\s*\]/[]/; > + } > + } > + > # check for multiple consecutive blank lines > if ($prevline =~ /^[\+ ]\s*$/ && > $line =~ /^\+\s*$/ && This is a question for Gustavo, who did all the work here. Gustavo, does the above checkpatch change look good to you? thanks, greg k-h
On Mon, 2022-10-03 at 07:29 +0200, Greg Kroah-Hartman wrote: > On Sun, Oct 02, 2022 at 06:46:30PM -0700, Joe Perches wrote: > > On Fri, 2022-09-30 at 14:22 +0200, Greg Kroah-Hartman wrote: > > > On Wed, Sep 28, 2022 at 12:56:31PM -0700, Elliot Berman wrote: > > > > Gunyah resource manager defines a simple API for virtual machine log > > > > sharing with the console service. > > [] > > > > diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h > > [] > > > > +struct gh_rm_notif_vm_console_chars { > > > > + u16 vmid; > > > > + u16 num_bytes; > > > > + u8 bytes[0]; > > > > > > Please do not use [0] for new structures, otherwise we will just have to > > > fix them up again as we are trying to get rid of all of these from the > > > kernel. Just use "bytes[];" instead. > > > > Maybe a checkpatch addition like: > > --- [] > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl [] > > @@ -3948,6 +3948,17 @@ sub process { > > } > > } > > > > +# check for zero length array declarations in likely structs > > + if ($line =~ /^\+\t($Declare\s*$Ident)\s*\[\s*0\s*\]\s*;\s*$/ && > > + defined $lines[$linenr] && > > + $lines[$linenr] =~ /^[\+ ]\}\s*(?:__\w+\s*(?:$balanced_parens)?)\s*;\s*$/) { This should actually be: $lines[$linenr] =~ /^[\+ ]\}(?:\s*__\w+\s*(?:$balanced_parens)?)*\s*;\s*$/) { as it was missing a * for uses like int foo[0]; } __packed __aligned(4); and uses without any attribute at all > > + if (WARN("FLEXIBLE_ARRAY_ZERO", > > + "Prefer flexible length array declarations with [] over [0]\n" . $herecurr) && > > + $fix) { > > + $fixed[$fixlinenr] =~ s/\[\s*0\s*\]/[]/; > > + } > > + } > > + > > # check for multiple consecutive blank lines > > if ($prevline =~ /^[\+ ]\s*$/ && > > $line =~ /^\+\s*$/ && > > This is a question for Gustavo, who did all the work here. Gustavo, > does the above checkpatch change look good to you?
On 10/3/22 00:38, Joe Perches wrote: > On Mon, 2022-10-03 at 07:29 +0200, Greg Kroah-Hartman wrote: >> On Sun, Oct 02, 2022 at 06:46:30PM -0700, Joe Perches wrote: >>> On Fri, 2022-09-30 at 14:22 +0200, Greg Kroah-Hartman wrote: >>>> On Wed, Sep 28, 2022 at 12:56:31PM -0700, Elliot Berman wrote: >>>>> Gunyah resource manager defines a simple API for virtual machine log >>>>> sharing with the console service. >>> [] >>>>> diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h >>> [] >>>>> +struct gh_rm_notif_vm_console_chars { >>>>> + u16 vmid; >>>>> + u16 num_bytes; >>>>> + u8 bytes[0]; >>>> >>>> Please do not use [0] for new structures, otherwise we will just have to >>>> fix them up again as we are trying to get rid of all of these from the >>>> kernel. Just use "bytes[];" instead. >>> >>> Maybe a checkpatch addition like: >>> --- > [] >>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > [] >>> @@ -3948,6 +3948,17 @@ sub process { >>> } >>> } >>> >>> +# check for zero length array declarations in likely structs >>> + if ($line =~ /^\+\t($Declare\s*$Ident)\s*\[\s*0\s*\]\s*;\s*$/ && >>> + defined $lines[$linenr] && >>> + $lines[$linenr] =~ /^[\+ ]\}\s*(?:__\w+\s*(?:$balanced_parens)?)\s*;\s*$/) { This sounds great. We need the same for one-element arrays. :) Both zero-length and one-element arrays are deprecated. > > This should actually be: > > $lines[$linenr] =~ /^[\+ ]\}(?:\s*__\w+\s*(?:$balanced_parens)?)*\s*;\s*$/) { I agree. Thanks. > > as it was missing a * for uses like > > int foo[0]; > } __packed __aligned(4); > > and uses without any attribute at all > >>> + if (WARN("FLEXIBLE_ARRAY_ZERO", >>> + "Prefer flexible length array declarations with [] over [0]\n" . $herecurr) && >>> + $fix) { >>> + $fixed[$fixlinenr] =~ s/\[\s*0\s*\]/[]/; >>> + } >>> + } >>> + >>> # check for multiple consecutive blank lines >>> if ($prevline =~ /^[\+ ]\s*$/ && >>> $line =~ /^\+\s*$/ && >> >> This is a question for Gustavo, who did all the work here. Gustavo, >> does the above checkpatch change look good to you? Yep; the idea is great. :) Another alternative to stop those fake flex-arrays from entering the codebase is to run Coccinelle scripts during linux-next builds, as suggested by Elena Reshetova at LSSEU a couple of months ago. However, if these can be stopped with checkpatch it'd be really helpful, as well. Thanks -- Gustavo
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 2737e4ced5745..187ed84c1f80a 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -3948,6 +3948,17 @@ sub process { } } +# check for zero length array declarations in likely structs + if ($line =~ /^\+\t($Declare\s*$Ident)\s*\[\s*0\s*\]\s*;\s*$/ && + defined $lines[$linenr] && + $lines[$linenr] =~ /^[\+ ]\}\s*(?:__\w+\s*(?:$balanced_parens)?)\s*;\s*$/) { + if (WARN("FLEXIBLE_ARRAY_ZERO", + "Prefer flexible length array declarations with [] over [0]\n" . $herecurr) && + $fix) { + $fixed[$fixlinenr] =~ s/\[\s*0\s*\]/[]/; + } + } + # check for multiple consecutive blank lines if ($prevline =~ /^[\+ ]\s*$/ && $line =~ /^\+\s*$/ &&