From: Joe Perches <joe@perches.com>
To: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: linux-kernel-mentees@lists.linuxfoundation.org,
linux-kernel <linux-kernel@vger.kernel.org>,
Lukas Bulwahn <lukas.bulwahn@gmail.com>
Subject: Re: [PATCH RFC v2] checkpatch: extend attributes check to handle more patterns
Date: Fri, 23 Oct 2020 05:08:14 -0700 [thread overview]
Message-ID: <2e8279841d604dde8a3335c092db921007f6744e.camel@perches.com> (raw)
In-Reply-To: <CABJPP5Dx4qj-_0gOx0bmaWvJj3okB-tNGJg5-8Y3KF2LnCjowQ@mail.gmail.com>
On Fri, 2020-10-23 at 17:10 +0530, Dwaipayan Ray wrote:
> On Fri, Oct 23, 2020 at 4:34 PM Joe Perches <joe@perches.com> wrote:
> >
> > On Fri, 2020-10-23 at 15:13 +0530, Dwaipayan Ray wrote:
> > > It is generally preferred that the macros from
> > > include/linux/compiler_attributes.h are used, unless there
> > > is a reason not to.
> > >
> > > Checkpatch currently checks __attribute__ for each of
> >
> > checkpatch, no need for capitalization
> >
> > and non-trivially:
> >
> > > + my $attr_list = qr {
> > > + __alias__|
> > > + __aligned__$|
> > > + __aligned__\(.*\)|
> > > + __always_inline__|
> > > + __assume_aligned__\(.*\)|
> > > + __cold__|
> > > + __const__|
> > > + __copy__\(.*\)|
> > > + __designated_init__|
> > > + __externally_visible__|
> > > + __fallthrough__|
> > > + __gnu_inline__|
> > > + __malloc__|
> > > + __mode__\(.*\)|
> > > + __no_caller_saved_registers__|
> > > + __noclone__|
> > > + __noinline__|
> > > + __nonstring__|
> > > + __noreturn__|
> > > + __packed__|
> > > + __pure__|
> > > + __used__
> > > + }x;
> > []
> > > + my %attr_replace = (
> > > + "__alias__" => "__alias",
> > > + "__aligned__" => "__aligned_largest",
> > > + "__aligned__(" => "__aligned",
> > > + "__always_inline__" => "__always_inline",
> > > + "__assume_aligned__(" => "__assume_aligned",
> > > + "__cold__" => "__cold",
> > > + "__const__" => "__const",
> > > + "__copy__(" => "__copy",
> > > + "__designated_init__" => "__designated_init",
> > > + "__externally_visible__" => "__visible",
> > > + "__fallthrough__" => "fallthrough",
> > > + "__gnu_inline__" => "__gnu_inline",
> > > + "__malloc__" => "__malloc",
> > > + "__mode__(" => "__mode",
> > > + "__no_caller_saved_registers__" => "__no_caller_saved_registers",
> > > + "__noclone__" => "__noclone",
> > > + "__noinline__" => "noinline",
> > > + "__nonstring__" => "__nonstring",
> > > + "__noreturn__" => "__noreturn",
> > > + "__packed__" => "__packed",
> > > + "__pure__" => "__pure",
> > > + "__used__" => "__used"
> > > + );
> > > +
> > > + if ($attr =~/^($attr_list)/) {
> >
> > I would remove the __ from the entries here.
> >
> > And you could check using
> >
> > $line =~ /__attribute__\s*\(\s*($balanced_parens)\s*)/
> >
> > and check for all attributes in $1 after
> > stripping the leading and trailing parens
> > and any leading and trailing underscores
> > from each attribute.
> >
> > And you only need one hash and you should
> > check for existence of the key rather than
> > have multiple lists.
> >
> > if (exists($attributes($attr))) {
> >
>
> Okay thanks!
> But what should be done for the attributes which are
> parameterized, like __aligned__(x). Should all the __
> for these entries be trimmed too?
yes
> There are also
> cases where there are multiple versions like:
>
> __aligned__
> __aligned__(x)
$ git grep __aligned__ | grep -v -P '__aligned__\s*\('
AFAIK: There is only one use of bare __aligned__ and
that's in compiler_attributes.h
> To help differentiate between them what can be done?
> Should i make the keys as:
>
> aligned
> aligned__(
>
> instead of
>
> __aligned__
> __aligned__(
Just use aligned
Just fyi:
these are the uses of __attribute__ in the kernel
with all the underscores and spaces removed so there's
some value in finding the multiple actual attributes .
$ git grep -ohP '__attribute__\s*\(\s*\(.*\)\s*\)' | \
sed -r -e 's/\s//g' -r -e 's/__(\w+)__/\1/g' | \
sort | uniq -c | sort -rn
2181 attribute((packed))
212 attribute((unused))
206 attribute((packed,aligned(4)))
131 attribute((aligned(8)))
77 attribute((aligned(32)))
74 attribute((always_inline))
68 attribute((noinline))
52 attribute((preserve_access_index))
48 attribute((weak))
38 attribute((noreturn))
38 attribute((aligned(16)))
25 attribute((packed,aligned(8)))
25 attribute((const))
18 attribute((aligned(64)))
17 attribute((aligned(256)))
17 attribute((aligned(128)))
16 attribute((used))
16 attribute((format(printf,1,2)))
15 attribute((aligned(4)))
14 attribute((constructor))
10 attribute((unused)))
10 attribute((pure))
10 attribute((mode(DI)))
10 attribute((aligned(SMP_CACHE_BYTES)))
9 attribute((format(printf,4,5)))
9 attribute((format(printf,2,3)))
9 attribute((aligned(sizeof(long))))
8 attribute((mode(SI)))
8 attribute((aligned(PAGE_SIZE)))
7 attribute((visibility("hidden")))
7 attribute((packed,aligned(2)))
6 attribute((section(NAME),used))
6 attribute((section("_ftrace_events")))
6 attribute((section(".data..read_mostly")))
6 attribute((section(".data")))
6 attribute((mode(word)))
5 attribute((format(printf,a,b)))
5 attribute((always_inline))typeof(name(0))
5 attribute((aligned(sizeof(unsignedlong))))
5 attribute((aligned(alignof(structebt_replace))))
5 attribute((aligned(AESNI_ALIGN)))
4 attribute((weak,alias("__vdso_clock_gettime")))
4 attribute((section("__trace_printk_fmt")))
4 attribute((section(".inittext")))
4 attribute((packed,aligned(256)))
4 attribute((packed,aligned(16)))
4 attribute((nonnull))
4 attribute((may_alias))
4 attribute((format(printf,3,4)))
4 attribute((fallthrough))
4 attribute((aligned(x)))
4 attribute((aligned(sizeof(void*))))
4 attribute((aligned(BITS_PER_LONG/8)))
4 attribute((aligned(alignof(u64))))
3 attribute((weak,alias("__vdso_gettimeofday")))
3 attribute((visibility("default")))
3 attribute((section("data_sec")))
3 attribute((regparm(0)))
3 attribute((nonnull(2,3)))
3 attribute((mode(TI)))
3 attribute((flatten))
3 attribute((destructor))
3 attribute((bitwise))
3 attribute((aligned(sizeof(uint64_t))))
3 attribute((aligned(sizeof(__u64))))
3 attribute((aligned(PADLOCK_ALIGNMENT)))
3 attribute((aligned(L1_CACHE_BYTES)))
3 attribute((aligned(a)))
3 attribute((alias("thermal_genl_event_tz")))
2 attribute((weak,unused))
2 attribute((weak,section(".rodata")))
2 attribute((weak,alias("__vdso_time")))
2 attribute((weak,alias("__vdso_getcpu")))
2 attribute((weak,alias("__vdso_clock_getres")))
2 attribute((warn_unused_result,nonnull))
2 attribute((vector_size(16)))
2 attribute((user))
2 attribute((section(".__syscall_stub")))
2 attribute((section(".maps."#name),used))
2 attribute((section("license"),used))
2 attribute((section("_ftrace_eval_map")))
2 attribute((section(".cpuidle.text")))
2 attribute((section("__builtin_cmdline")))
2 attribute((section(".arch.info.init")))
2 attribute((packed,aligned(PMCRAID_IOARCB_ALIGNMENT)))
2 attribute((packed,aligned(64)))
2 attribute((no_sanitize_address))
2 attribute((noreturn,unused))
2 attribute((nonnull(2)))
2 attribute((no_instrument_function))
2 attribute((model(small)))
2 attribute((malloc))
2 attribute((latent_entropy))
2 attribute((gnu_inline))
2 attribute((format(scanf,a,b)))
2 attribute((format(printf,1,2)))attribute((noreturn))
2 attribute((force))
2 attribute((externally_visible))
2 attribute((error(message)))
2 attribute((common))
2 attribute((aligned(XCHAL_NCP_SA_ALIGN)))
2 attribute((aligned(VRING_USED_ALIGN_SIZE)))
2 attribute((aligned((sizeof(long)))))
2 attribute((aligned(sizeof(Elf##size##_Word))))
2 attribute((aligned(65536)))
2 attribute((aligned(512)))
2 attribute((aligned(4*sizeof(__u64))))
2 attribute((aligned(32),packed))
2 attribute((aligned(0x20000)))
2 attribute((alias(__stringify(__se_sys##name))))
2 attribute((alias(__stringify(__se_compat_sys##name))))
2 attribute((alias("cfi_cmdset_0002")))
2 attribute((alias("cfi_cmdset_0001")))
1 attribute((weakref("dsdt_aml_code")))
1 attribute((weakref("AmlCode")))
1 attribute((weak,alias("__vdso_clock_gettime64")))
1 attribute((weak,alias("__platform_"#f)))
1 attribute((weak,alias("__mips_cm_phys_base")))
1 attribute((weak,alias("__mips_cm_l2sync_phys_base")))
1 attribute((weak,alias("__alloc_bootmem_huge_page")))
1 attribute((warn_unused_result))
1 attribute((warning(message)))
1 attribute((vector_size(8)))
1 attribute((used,section(".videocards")))
1 attribute((used,section(".taglist")))
1 attribute((unused,section("__param"),aligned(sizeof(void*))))
1 attribute((unused,alias(__stringify(name))))
1 attribute((tls_model("initial-exec"),unused))
1 attribute((tls_model("initial-exec")))
1 attribute((target("no-vsx")))
1 attribute((syscall_linkage))
1 attribute((section(".xiptext")))
1 attribute((section(".x86_intel_mid_dev.init")))
1 attribute((section(".x86_cpu_dev.init")))
1 attribute((section(".vvar_"#name),aligned(16)))
1 attribute((section(".text.hot")))
1 attribute((section(".taglist.init")))
1 attribute((section("__syscalls_metadata")))
1 attribute((section("__stop_sched_class")))
1 attribute((section(".spinlock.text")))
1 attribute((section(".softirqentry.text")))
1 attribute((section(#section),aligned((sizeof(void*)))))
1 attribute((section(#__sec".init")))
1 attribute((section(".sched.text")))
1 attribute((section(#S)))
1 attribute((section("__rt_sched_class")))
1 attribute((section(PER_CPU_BASE_SECTIONsec)))
1 attribute((section("__modver")))
1 attribute((section(".modinfo"),unused,aligned(1)))
1 attribute((section(".machine.desc")))
1 attribute((section("___ksymtab"sec"+"#sym),used))
1 attribute((section(".ksyms")))
1 attribute((section(".kprobes.text")))
1 attribute((section("_kprobe_blacklist")))
1 attribute((section("___kentry+"#sym)))
1 attribute((section(".kconfig")))
1 attribute((section(".irqentry.text")))
1 attribute((section(".initcall"level".init")))
1 attribute((section("__idle_sched_class")))
1 attribute((section("__fair_sched_class")))
1 attribute((section("_error_injection_whitelist")))
1 attribute((section("__dl_sched_class")))
1 attribute((section(".discard"),unused))
1 attribute((section(".data..vm0.pte"),aligned(PAGE_SIZE)))
1 attribute((section(".data..vm0.pmd"),aligned(PAGE_SIZE)))
1 attribute((section(".data..vm0.pgd"),aligned(PAGE_SIZE)))
1 attribute((section(".data..ro_after_init")))
1 attribute((section(".data..init_thread_info")))
1 attribute((section(".data..init_task")))
1 attribute((section(".data..init_irqstack")))
1 attribute((section(".bss..decrypted")))
1 attribute((section("__bpf_raw_tp_map")))
1 attribute((section("action-ok"),used))
1 attribute((section("action-ko"),used))
1 attribute((section($old)))
1 attribute((safe))
1 attribute((returns_twice))
1 attribute((require_context(x,1,999,"write")))
1 attribute((require_context(x,1,999,"read")))
1 attribute((require_context(x,1,999,"rdwr")))
1 attribute((randomize_layout))
1 attribute((patchable_function_entry(0,0)))
1 attribute((packed,deprecated))
1 attribute((packed,aligned(XSAVE_ALIGNMENT)))
1 attribute((packed,aligned(PMCRAID_IOADL_ALIGNMENT)))
1 attribute((packed,aligned(PAGE_SIZE)))
1 attribute((packed,aligned(2048)))
1 attribute((packed,aligned(1024)))
1 attribute((optimize("no-stack-protector")))
1 attribute((optimize("no-optimize-sibling-calls")))
1 attribute((optimize("-fno-gcse")))
1 attribute((no_sanitize_undefined))
1 attribute((no_sanitize("undefined")))
1 attribute((no_sanitize_thread))
1 attribute((no_sanitize("thread")))
1 attribute((no_sanitize("shadow-call-stack")))
1 attribute((no_sanitize("address","hwaddress")))
1 attribute((noreturn))__attribute((format(printf,1,2)))
1 attribute((no_randomize_layout))
1 attribute((nonstring))
1 attribute((nonnull(2,3,4,5)))
1 attribute((nonnull(2,3,4)))
1 attribute((nonnull(1)))
1 attribute((noderef,address_space(__user)))
1 attribute((noderef,address_space(__rcu)))
1 attribute((noderef,address_space(__percpu)))
1 attribute((noderef,address_space(__iomem)))
1 attribute((noderef))
1 attribute((noclone))
1 attribute((nocast))
1 attribute((no_caller_saved_registers))
1 attribute((name))
1 attribute((naked))
1 attribute((ms_abi))
1 attribute((mode(x)))
1 attribute((mode(TF)))
1 attribute((mode(QI)))
1 attribute((mode(HI)))
1 attribute((long_call))
1 attribute((indirect_branch("keep")))
1 attribute((hotpatch(0,0)))
1 attribute((hot))
1 attribute((format(scanf,string-index,first-to-check)))
1 attribute((format(printf,string-index,first-to-check)))
1 attribute((format(printf,(pos_fmtstr),(pos_fmtargs))))
1 attribute((format(printf,i,j)))
1 attribute((format(printf,c,c+1)))
1 attribute((format(printf,5,6)))
1 attribute((format(printf,2,0)))
1 attribute((format(gnu_printf,i,j)))
1 attribute((disable_tail_calls))
1 attribute((designated_init))
1 attribute((deprecated(msg)))
1 attribute((deprecated))
1 attribute((copy(symbol)))
1 attribute((context(x,1,1)))
1 attribute((context(x,1,0)))
1 attribute((context(x,0,1)))
1 attribute((cold))
1 attribute((cleanup(kcsan_end_scoped_access)))
1 attribute((assume_aligned(a,##VA_ARGS)))
1 attribute((align_value(8)))
1 attribute((aligned(XCHAL_CP7_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP6_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP5_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP4_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP3_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP2_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP1_SA_ALIGN)))
1 attribute((aligned(XCHAL_CP0_SA_ALIGN)))
1 attribute((aligned(VRING_DESC_ALIGN_SIZE)))
1 attribute((aligned(VRING_AVAIL_ALIGN_SIZE)))
1 attribute((aligned(TSB_ENTRY_ALIGNMENT)))
1 attribute((aligned(TPACKET_ALIGN(x))))
1 attribute((aligned(TPACKET_ALIGNMENT)))
1 attribute((aligned(stackalign)))
1 attribute((aligned(sizeof(u64))))
1 attribute((aligned(sizeof(u32))))
1 attribute((aligned(sizeof(__u32))))
1 attribute((aligned(sizeof(s64))))
1 attribute((aligned(sizeof(kernel_ulong_t))))
1 attribute((aligned(size)))
1 attribute((aligned(PS3_BMP_MINALIGN)))
1 attribute((aligned(_K_SS_ALIGNSIZE)))
1 attribute((aligned(INTERNODE_CACHE_BYTES)))
1 attribute((aligned(GRU_CACHE_LINE_BYTES)))
1 attribute((aligned(DM_IO_MAX_REGIONS)))
1 attribute((aligned(CVMX_CACHE_LINE_SIZE)))
1 attribute((aligned(CRYPTO_MINALIGN)))
1 attribute((aligned(CPPI_DESCRIPTOR_ALIGN)))
1 attribute((aligned(ALIGN_SIZE)))
1 attribute((aligned(alignof(u32))))
1 attribute((aligned(alignof(structnft_expr))))
1 attribute((aligned(alignof(structhash_alg_common))))
1 attribute((aligned(4096)))
1 attribute((aligned(2*sizeof(long))))
1 attribute((aligned(2),packed))
1 attribute((aligned(256),packed))
1 attribute((aligned(2048)))
1 attribute((aligned(2)))
1 attribute((aligned(1<<(INTERNODE_CACHE_SHIFT))))
1 attribute((aligned(1024),packed))
1 attribute((aligned(0x80)))
1 attribute((aligned(0x2000)))
1 attribute((aligned))
1 attribute((alias("vtime_account_irq_enter")))
1 attribute((alias("thermal_genl_event_tz_trip_up")))
1 attribute((alias("thermal_genl_event_tz_trip_add")))
1 attribute((alias(#system"_mv")))
1 attribute((alias(#symbol)))
1 attribute((alias(__stringify(__s390x_sys_##sname))))
1 attribute((alias("octeon_board_type_string")))
1 attribute((alias("native_sched_clock")))
1 attribute((alias(istringify(SIG_EXPR_LIST_SYM(sig,group)))))
1 attribute((alias(#internal_name)))
1 attribute((alias(#initfn)))
1 attribute((alias(#exitfn)))
1 attribute((address_space(257))
1 attribute((address_space(256))
1 attribute((address_space(0)))
next prev parent reply other threads:[~2020-10-23 12:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-23 9:43 Dwaipayan Ray
2020-10-23 11:04 ` Joe Perches
2020-10-23 11:40 ` Dwaipayan Ray
2020-10-23 12:08 ` Joe Perches [this message]
2020-10-23 19:14 ` Dwaipayan Ray
2020-10-23 20:42 ` Joe Perches
2020-10-23 20:57 ` Dwaipayan Ray
2020-10-23 21:04 ` Joe Perches
2020-10-23 21:09 ` Dwaipayan Ray
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