Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Joe Perches]

On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
> On Mon, Oct 28, 2019 at 12:43 PM Joe Perches <joe@perches.com> wrote:
> > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> > index 72393a..b8c2145 100644
> > --- a/include/linux/compiler_types.h
> > +++ b/include/linux/compiler_types.h
> > @@ -5,27 +5,27 @@
> >  #ifndef __ASSEMBLY__
> > 
> >  #ifdef __CHECKER__
> > -# define __user                __attribute__((noderef, address_space(1)))
[]
> Just in case: for these ones (i.e. __CHECKER__), did you check if
> sparse handles this syntax? (I don't recall myself if it does).
> 
> Other than that, thanks for the cleanup too! I can pick it up in the
> the compiler-attributes tree and put it in -next.

Thanks for asking and no, I did  not until just now.
Turns out sparse does _not_ handle these changes and
the checking fails for these __<changes>__.

sparse would have to update parse.c or the __CHECKER__
changes would need to be reverted.

Perhaps update parse.c like:
---
 parse.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/parse.c b/parse.c
index 48a63..4464e 100644
--- a/parse.c
+++ b/parse.c
@@ -549,13 +549,19 @@ static struct init_keyword {
 	{ "aligned",	NS_KEYWORD, .op = &aligned_op },
 	{ "__aligned__",NS_KEYWORD, .op = &aligned_op },
 	{ "nocast",	NS_KEYWORD,	MOD_NOCAST,	.op = &attr_mod_op },
+	{ "__nocast__",	NS_KEYWORD,	MOD_NOCAST,	.op = &attr_mod_op },
 	{ "noderef",	NS_KEYWORD,	MOD_NODEREF,	.op = &attr_mod_op },
+	{ "__noderef__",NS_KEYWORD,	MOD_NODEREF,	.op = &attr_mod_op },
 	{ "safe",	NS_KEYWORD,	MOD_SAFE, 	.op = &attr_mod_op },
+	{ "__safe__",	NS_KEYWORD,	MOD_SAFE, 	.op = &attr_mod_op },
 	{ "force",	NS_KEYWORD,	.op = &attr_force_op },
+	{ "__force__",	NS_KEYWORD,	.op = &attr_force_op },
 	{ "bitwise",	NS_KEYWORD,	MOD_BITWISE,	.op = &attr_bitwise_op },
 	{ "__bitwise__",NS_KEYWORD,	MOD_BITWISE,	.op = &attr_bitwise_op },
 	{ "address_space",NS_KEYWORD,	.op = &address_space_op },
+	{ "__address_space__",NS_KEYWORD,	.op = &address_space_op },
 	{ "context",	NS_KEYWORD,	.op = &context_op },
+	{ "__context__",NS_KEYWORD,	.op = &context_op },
 	{ "designated_init",	NS_KEYWORD,	.op = &designated_init_op },
 	{ "__designated_init__",	NS_KEYWORD,	.op = &designated_init_op },
 	{ "transparent_union",	NS_KEYWORD,	.op = &transparent_union_op },

[PATCH V2] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Joe Perches]

To avoid macro name collisions and improve portability use a
double underscore prefix and suffix on all __attribute__ #defines.

There are __CHECKER__ exceptions to these uses of attribute types
because sparse as of version 0.6.1 and earlier do not recognize
a few __<type>__ attributes.

Signed-off-by: Joe Perches <joe@perches.com>
---

v2: Do not modify the __CHECKER__ attribute #defines
    Add a comment describing why to the __CHECKER__ block.

 include/linux/compiler-clang.h |  2 +-
 include/linux/compiler-gcc.h   | 10 +++++-----
 include/linux/compiler_types.h | 11 ++++++++---
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index 333a66..26d655f 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -19,7 +19,7 @@
 /* emulate gcc's __SANITIZE_ADDRESS__ flag */
 #define __SANITIZE_ADDRESS__
 #define __no_sanitize_address \
-		__attribute__((no_sanitize("address", "hwaddress")))
+		__attribute__((__no_sanitize__("address", "hwaddress")))
 #else
 #define __no_sanitize_address
 #endif
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index d7ee4c..7a2dee 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -76,7 +76,7 @@
 #define __compiletime_error(message) __attribute__((__error__(message)))
 
 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
-#define __latent_entropy __attribute__((latent_entropy))
+#define __latent_entropy __attribute__((__latent_entropy__))
 #endif
 
 /*
@@ -101,8 +101,8 @@
 	} while (0)
 
 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
-#define __randomize_layout __attribute__((randomize_layout))
-#define __no_randomize_layout __attribute__((no_randomize_layout))
+#define __randomize_layout __attribute__((__randomize_layout__))
+#define __no_randomize_layout __attribute__((__no_randomize_layout__))
 /* This anon struct can add padding, so only enable it under randstruct. */
 #define randomized_struct_fields_start	struct {
 #define randomized_struct_fields_end	} __randomize_layout;
@@ -140,7 +140,7 @@
 #endif
 
 #if __has_attribute(__no_sanitize_address__)
-#define __no_sanitize_address __attribute__((no_sanitize_address))
+#define __no_sanitize_address __attribute__((__no_sanitize_address__))
 #else
 #define __no_sanitize_address
 #endif
@@ -171,4 +171,4 @@
 #define __diag_GCC_8(s)
 #endif
 
-#define __no_fgcse __attribute__((optimize("-fno-gcse")))
+#define __no_fgcse __attribute__((__optimize__("-fno-gcse")))
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 72393a..506b3a 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -5,6 +5,11 @@
 #ifndef __ASSEMBLY__
 
 #ifdef __CHECKER__
+/*
+ * sparse as of v0.6.1 does not understand several double underscore
+ * prefix and suffix forms of attribute types, so do not use them when
+ * sparse checking is enabled
+ */
 # define __user		__attribute__((noderef, address_space(1)))
 # define __kernel	__attribute__((address_space(0)))
 # define __safe		__attribute__((safe))
@@ -25,7 +30,7 @@ extern void __chk_io_ptr(const volatile void __iomem *);
 # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
 #else /* __CHECKER__ */
 # ifdef STRUCTLEAK_PLUGIN
-#  define __user __attribute__((user))
+#  define __user __attribute__((__user__))
 # else
 #  define __user
 # endif
@@ -111,9 +116,9 @@ struct ftrace_likely_data {
 #endif
 
 #if defined(CC_USING_HOTPATCH)
-#define notrace			__attribute__((hotpatch(0, 0)))
+#define notrace			__attribute__((__hotpatch__(0, 0)))
 #elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
-#define notrace			__attribute__((patchable_function_entry(0, 0)))
+#define notrace			__attribute__((__patchable_function_entry__(0, 0)))
 #else
 #define notrace			__attribute__((__no_instrument_function__))
 #endif

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Luc Van Oostenryck]

On Mon, Oct 28, 2019 at 10:59:47AM -0700, Joe Perches wrote:
> On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
> > Just in case: for these ones (i.e. __CHECKER__), did you check if
> > sparse handles this syntax? (I don't recall myself if it does).
> > 
> > Other than that, thanks for the cleanup too! I can pick it up in the
> > the compiler-attributes tree and put it in -next.
> 
> Thanks for asking and no, I did  not until just now.
> Turns out sparse does _not_ handle these changes and
> the checking fails for these __<changes>__.
> 
> sparse would have to update parse.c or the __CHECKER__
> changes would need to be reverted.
> 
> Perhaps update parse.c like:

...

Yes, this was missing. Thanks.
Can I have your SoB for this?

-- Luc

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Joe Perches]

On Mon, 2019-10-28 at 23:15 +0100, Luc Van Oostenryck wrote:
> On Mon, Oct 28, 2019 at 10:59:47AM -0700, Joe Perches wrote:
> > On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
> > > Just in case: for these ones (i.e. __CHECKER__), did you check if
> > > sparse handles this syntax? (I don't recall myself if it does).
> > > 
> > > Other than that, thanks for the cleanup too! I can pick it up in the
> > > the compiler-attributes tree and put it in -next.
> > 
> > Thanks for asking and no, I did  not until just now.
> > Turns out sparse does _not_ handle these changes and
> > the checking fails for these __<changes>__.
> > 
> > sparse would have to update parse.c or the __CHECKER__
> > changes would need to be reverted.
> > 
> > Perhaps update parse.c like:
> 
> ...
> 
> Yes, this was missing. Thanks.
> Can I have your SoB for this?

I'm not sure this actually works as there's
some possible sparse parsing changes in the
use of __context__.

There is a difference in linux compilation of
a defconfig output with sparse output of init/
with the new parse.c 

old:

$ make clean ; make C=1 init > old 2>&1

(recompile sparse with changes above)

new:

$ make clean ; make C=1 init > new 2>&1

$ diff -urN old new
--- old	2019-10-28 15:20:00.524678375 -0700
+++ new	2019-10-28 15:21:14.004674721 -0700
@@ -55,7 +55,25 @@
   CHK     include/generated/compile.h
   CHECK   init/main.c
 init/main.c:173:12: warning: symbol 'envp_init' was not declared. Should it be static?
+./include/linux/rcupdate.h:598:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:651:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:598:9: error: not a function <noident>
+./include/linux/rcupdate.h:598:9: error: undefined identifier 'RCU'
+./include/linux/rcupdate.h:651:9: error: not a function <noident>
+./include/linux/rcupdate.h:651:9: error: undefined identifier 'RCU'
 init/main.c:506:20: warning: symbol 'mem_encrypt_init' was not declared. Should it be static?
+./include/linux/rcupdate.h:716:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:736:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:716:9: error: undefined identifier 'RCU_SCHED'
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: undefined identifier 'RCU_SCHED'
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/spinlock.h:211:9: error: undefined identifier '__context__'
+init/main.c:1222:9: warning: context imbalance in 'kernel_init_freeable' - wrong count at exit
   CC      init/main.o
   CHECK   init/version.c
   CC      init/version.o

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Luc Van Oostenryck]

On Mon, Oct 28, 2019 at 03:28:17PM -0700, Joe Perches wrote:
> On Mon, 2019-10-28 at 23:15 +0100, Luc Van Oostenryck wrote:
> > On Mon, Oct 28, 2019 at 10:59:47AM -0700, Joe Perches wrote:
> > > On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
> > > > Just in case: for these ones (i.e. __CHECKER__), did you check if
> > > > sparse handles this syntax? (I don't recall myself if it does).
> > > > 
> > > > Other than that, thanks for the cleanup too! I can pick it up in the
> > > > the compiler-attributes tree and put it in -next.
> > > 
> > > Thanks for asking and no, I did  not until just now.
> > > Turns out sparse does _not_ handle these changes and
> > > the checking fails for these __<changes>__.
> > > 
> > > sparse would have to update parse.c or the __CHECKER__
> > > changes would need to be reverted.
> > > 
> > > Perhaps update parse.c like:
> > 
> > ...
> > 
> > Yes, this was missing. Thanks.
> > Can I have your SoB for this?
> 
> I'm not sure this actually works as there's
> some possible sparse parsing changes in the
> use of __context__.

Yes, indeed. The following shoud be squashed on top of
your patch (not tested yet on linux side):

-- Luc

diff --git a/parse.c b/parse.c
index 4464e2667..4b0a1566c 100644
--- a/parse.c
+++ b/parse.c
@@ -345,6 +345,7 @@ static struct symbol_op goto_op = {
 
 static struct symbol_op __context___op = {
 	.statement = parse_context_statement,
+	.attribute = attribute_context,
 };
 
 static struct symbol_op range_op = {
@@ -537,6 +538,7 @@ static struct init_keyword {
 	{ "while",	NS_KEYWORD, .op = &while_op },
 	{ "do",		NS_KEYWORD, .op = &do_op },
 	{ "goto",	NS_KEYWORD, .op = &goto_op },
+	{ "context",	NS_KEYWORD, .op = &context_op },
 	{ "__context__",NS_KEYWORD, .op = &__context___op },
 	{ "__range__",	NS_KEYWORD, .op = &range_op },
 	{ "asm",	NS_KEYWORD, .op = &asm_op },
@@ -560,8 +562,6 @@ static struct init_keyword {
 	{ "__bitwise__",NS_KEYWORD,	MOD_BITWISE,	.op = &attr_bitwise_op },
 	{ "address_space",NS_KEYWORD,	.op = &address_space_op },
 	{ "__address_space__",NS_KEYWORD,	.op = &address_space_op },
-	{ "context",	NS_KEYWORD,	.op = &context_op },
-	{ "__context__",NS_KEYWORD,	.op = &context_op },
 	{ "designated_init",	NS_KEYWORD,	.op = &designated_init_op },
 	{ "__designated_init__",	NS_KEYWORD,	.op = &designated_init_op },
 	{ "transparent_union",	NS_KEYWORD,	.op = &transparent_union_op },

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Ramsay Jones]

On 28/10/2019 23:03, Luc Van Oostenryck wrote:
> On Mon, Oct 28, 2019 at 03:28:17PM -0700, Joe Perches wrote:
>> On Mon, 2019-10-28 at 23:15 +0100, Luc Van Oostenryck wrote:
>>> On Mon, Oct 28, 2019 at 10:59:47AM -0700, Joe Perches wrote:
>>>> On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
>>>>> Just in case: for these ones (i.e. __CHECKER__), did you check if
>>>>> sparse handles this syntax? (I don't recall myself if it does).
>>>>>
>>>>> Other than that, thanks for the cleanup too! I can pick it up in the
>>>>> the compiler-attributes tree and put it in -next.
>>>>
>>>> Thanks for asking and no, I did  not until just now.
>>>> Turns out sparse does _not_ handle these changes and
>>>> the checking fails for these __<changes>__.
>>>>
>>>> sparse would have to update parse.c or the __CHECKER__
>>>> changes would need to be reverted.
>>>>
>>>> Perhaps update parse.c like:
>>>
>>> ...
>>>
>>> Yes, this was missing. Thanks.
>>> Can I have your SoB for this?
>>
>> I'm not sure this actually works as there's
>> some possible sparse parsing changes in the
>> use of __context__.
> 
> Yes, indeed. The following shoud be squashed on top of
> your patch (not tested yet on linux side):
> 
> -- Luc
> 
> diff --git a/parse.c b/parse.c
> index 4464e2667..4b0a1566c 100644
> --- a/parse.c
> +++ b/parse.c
> @@ -345,6 +345,7 @@ static struct symbol_op goto_op = {
>  
>  static struct symbol_op __context___op = {
>  	.statement = parse_context_statement,
> +	.attribute = attribute_context,

Hmm, so why is do we have a context_op and a __context___op?

>  };
>  
>  static struct symbol_op range_op = {
> @@ -537,6 +538,7 @@ static struct init_keyword {
>  	{ "while",	NS_KEYWORD, .op = &while_op },
>  	{ "do",		NS_KEYWORD, .op = &do_op },
>  	{ "goto",	NS_KEYWORD, .op = &goto_op },
> +	{ "context",	NS_KEYWORD, .op = &context_op },
>  	{ "__context__",NS_KEYWORD, .op = &__context___op },

So, can '__context__' be used in a statement, as well as an
attribute, while 'context' can only be used in an attribute?

Confused.

ATB,
Ramsay Jones

>  	{ "__range__",	NS_KEYWORD, .op = &range_op },
>  	{ "asm",	NS_KEYWORD, .op = &asm_op },
> @@ -560,8 +562,6 @@ static struct init_keyword {
>  	{ "__bitwise__",NS_KEYWORD,	MOD_BITWISE,	.op = &attr_bitwise_op },
>  	{ "address_space",NS_KEYWORD,	.op = &address_space_op },
>  	{ "__address_space__",NS_KEYWORD,	.op = &address_space_op },
> -	{ "context",	NS_KEYWORD,	.op = &context_op },
> -	{ "__context__",NS_KEYWORD,	.op = &context_op },
>  	{ "designated_init",	NS_KEYWORD,	.op = &designated_init_op },
>  	{ "__designated_init__",	NS_KEYWORD,	.op = &designated_init_op },
>  	{ "transparent_union",	NS_KEYWORD,	.op = &transparent_union_op },
> 

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Luc Van Oostenryck]

On Tue, Oct 29, 2019 at 02:38:54AM +0000, Ramsay Jones wrote:
> On 28/10/2019 23:03, Luc Van Oostenryck wrote:
> > diff --git a/parse.c b/parse.c
> > index 4464e2667..4b0a1566c 100644
> > --- a/parse.c
> > +++ b/parse.c
> > @@ -345,6 +345,7 @@ static struct symbol_op goto_op = {
> >  
> >  static struct symbol_op __context___op = {
> >  	.statement = parse_context_statement,
> > +	.attribute = attribute_context,
> 
> Hmm, so why is do we have a context_op and a __context___op?
> 
> >  };
> >  
> >  static struct symbol_op range_op = {
> > @@ -537,6 +538,7 @@ static struct init_keyword {
> >  	{ "while",	NS_KEYWORD, .op = &while_op },
> >  	{ "do",		NS_KEYWORD, .op = &do_op },
> >  	{ "goto",	NS_KEYWORD, .op = &goto_op },
> > +	{ "context",	NS_KEYWORD, .op = &context_op },
> >  	{ "__context__",NS_KEYWORD, .op = &__context___op },
> 
> So, can '__context__' be used in a statement, as well as an
> attribute, while 'context' can only be used in an attribute?

Yes, indeed.
'__context__' was only parsed as a statement and 'context'
only as an attribute. But now we also want to be able to use
'__context__' as an attribute (because 'context' is not a
reserved keyword and can thus be a used defined macro).

There is no reason, though, we should now also want to use
'context' as a statement since it's a sparse extension. Hence
adding attribute_context to '__context___op' and keeping
'context_op' as such (but moving them together).

-- Luc

Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Ramsay Jones]

On 29/10/2019 08:07, Luc Van Oostenryck wrote:
> On Tue, Oct 29, 2019 at 02:38:54AM +0000, Ramsay Jones wrote:
>> On 28/10/2019 23:03, Luc Van Oostenryck wrote:
>>> diff --git a/parse.c b/parse.c
>>> index 4464e2667..4b0a1566c 100644
>>> --- a/parse.c
>>> +++ b/parse.c
>>> @@ -345,6 +345,7 @@ static struct symbol_op goto_op = {
>>>  
>>>  static struct symbol_op __context___op = {
>>>  	.statement = parse_context_statement,
>>> +	.attribute = attribute_context,
>>
>> Hmm, so why is do we have a context_op and a __context___op?
>>
>>>  };
>>>  
>>>  static struct symbol_op range_op = {
>>> @@ -537,6 +538,7 @@ static struct init_keyword {
>>>  	{ "while",	NS_KEYWORD, .op = &while_op },
>>>  	{ "do",		NS_KEYWORD, .op = &do_op },
>>>  	{ "goto",	NS_KEYWORD, .op = &goto_op },
>>> +	{ "context",	NS_KEYWORD, .op = &context_op },
>>>  	{ "__context__",NS_KEYWORD, .op = &__context___op },
>>
>> So, can '__context__' be used in a statement, as well as an
>> attribute, while 'context' can only be used in an attribute?
> 
> Yes, indeed.

OK, so I wasn't quite as confused as I thought! ;-)

> '__context__' was only parsed as a statement and 'context'
> only as an attribute. But now we also want to be able to use
> '__context__' as an attribute (because 'context' is not a
> reserved keyword and can thus be a used defined macro).
> 
> There is no reason, though, we should now also want to use
> 'context' as a statement since it's a sparse extension. Hence
> adding attribute_context to '__context___op' and keeping
> 'context_op' as such (but moving them together).

Thanks for the explanation.

ATB,
Ramsay Jones