genksyms: Handle typeof_unqual keyword and __seg_{fs,gs} qualifiers

Handle typeof_unqual, __typeof_unqual and __typeof_unqual__ keywords
using TYPEOF_KEYW token in the same way as typeof keyword.

A

genksyms: Handle typeof_unqual keyword and __seg_{fs,gs} qualifiers

Handle typeof_unqual, __typeof_unqual and __typeof_unqual__ keywords
using TYPEOF_KEYW token in the same way as typeof keyword.

Also ignore x86 __seg_fs and __seg_gs named address space qualifiers
using X86_SEG_KEYW token in the same way as const, volatile or
restrict qualifiers.

Fixes: ac053946f5c4 ("compiler.h: introduce TYPEOF_UNQUAL() macro")
Closes: https://lore.kernel.org/lkml/[email protected]/
Reported-by: Paul Menzel <[email protected]>
Signed-off-by: Uros Bizjak <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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genksyms: fix syntax error for attribute before init-declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

For example, genksyms fails to parse the following valid code

genksyms: fix syntax error for attribute before init-declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

For example, genksyms fails to parse the following valid code:

int x, __attribute__((__section__(".init.data")))y;

Here, only 'y' is annotated by the attribute, although I am not aware
of actual uses of this pattern in the kernel tree.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

$ echo 'int x, __attribute__((__section__(".init.data")))y;' | scripts/genksyms/genksyms -w
<stdin>:1: syntax error

This commit allows attributes to be placed between a comma and
init_declarator.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

show more ...

genksyms: fix syntax error for attribute after 'union'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_p

genksyms: fix syntax error for attribute after 'union'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

$ make -s KCFLAGS=-D__GENKSYMS__ fs/lockd/svc.i
$ cat fs/lockd/svc.i | scripts/genksyms/genksyms -w
[ snip ]
./include/net/addrconf.h:35: syntax error

The syntax error occurs in the following code in include/net/addrconf.h:

union __packed {
[ snip ]
};

The issue arises from __packed, which is defined as
__attribute__((__packed__)), immediately after the 'union' keyword.

This commit allows the 'union' keyword to be followed by attributes.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix syntax error for attribute after 'struct'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_

genksyms: fix syntax error for attribute after 'struct'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

$ make -s KCFLAGS=-D__GENKSYMS__ arch/x86/kernel/cpu/mshyperv.i
$ cat arch/x86/kernel/cpu/mshyperv.i | scripts/genksyms/genksyms -w
[ snip ]
./arch/x86/include/asm/svm.h:122: syntax error

The syntax error occurs in the following code in arch/x86/include/asm/svm.h:

struct __attribute__ ((__packed__)) vmcb_control_area {
[ snip ]
};

The issue arises from __attribute__ immediately after the 'struct'
keyword.

This commit allows the 'struct' keyword to be followed by attributes.

The lexer must be adjusted because dont_want_brace_phase should not be
decremented while processing attributes.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix syntax error for attribute after abstact_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
e

genksyms: fix syntax error for attribute after abstact_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

$ make -s KCFLAGS=-D__GENKSYMS__ kernel/module/main.i
$ cat kernel/module/main.i | scripts/genksyms/genksyms -w
[ snip ]
kernel/module/main.c:97: syntax error

The syntax error occurs in the following code in kernel/module/main.c:

static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
unsigned int size, struct mod_tree_root *tree)
{
[ snip ]
}

The issue arises from __maybe_unused, which is defined as
__attribute__((__unused__)).

This commit allows direct_abstract_declarator to be followed with
attributes.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix syntax error for attribute before nested_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
e

genksyms: fix syntax error for attribute before nested_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

$ make -s KCFLAGS=-D__GENKSYMS__ drivers/acpi/prmt.i
$ cat drivers/acpi/prmt.i | scripts/genksyms/genksyms -w
[ snip ]
drivers/acpi/prmt.c:56: syntax error

The syntax error occurs in the following code in drivers/acpi/prmt.c:

struct prm_handler_info {
[ snip ]
efi_status_t (__efiapi *handler_addr)(u64, void *);
[ snip ]
};

The issue arises from __efiapi, which is defined as either
__attribute__((ms_abi)) or __attribute__((regparm(0))).

This commit allows nested_declarator to be prefixed with attributes.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

show more ...

genksyms: fix syntax error for attribute before abstract_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,

genksyms: fix syntax error for attribute before abstract_declarator

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

$ make -s KCFLAGS=-D__GENKSYMS__ init/main.i
$ cat init/main.i | scripts/genksyms/genksyms -w
[ snip ]
./include/linux/efi.h:1225: syntax error

The syntax error occurs in the following code in include/linux/efi.h:

efi_status_t
efi_call_acpi_prm_handler(efi_status_t (__efiapi *handler_addr)(u64, void *),
u64 param_buffer_addr, void *context);

The issue arises from __efiapi, which is defined as either
__attribute__((ms_abi)) or __attribute__((regparm(0))).

This commit allows abstract_declarator to be prefixed with attributes.

To avoid conflicts, I tweaked the rule for decl_specifier_seq. Due to
this change, a standalone attribute cannot become decl_specifier_seq.
Otherwise, I do not know how to resolve the conflicts.

The following code, which was previously accepted by genksyms, will now
result in a syntax error:

void my_func(__attribute__((unused))x);

I do not think it is a big deal because GCC also fails to parse it.

$ echo 'void my_func(__attribute__((unused))x);' | gcc -c -x c -
<stdin>:1:37: error: unknown type name 'x'

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier

The __attribute__ keyword can appear in more contexts than 'const' or
'volatile'.

To avoid grammatical conflicts with future changes, ATTRIBU

genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier

The __attribute__ keyword can appear in more contexts than 'const' or
'volatile'.

To avoid grammatical conflicts with future changes, ATTRIBUTE_PHRASE
should not be reduced into type_qualifier.

No functional changes are intended.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: record attributes consistently for init-declarator

I believe the missing action here is a bug.

For rules with no explicit action, the following default is used:

{ $$ = $1; }

However

genksyms: record attributes consistently for init-declarator

I believe the missing action here is a bug.

For rules with no explicit action, the following default is used:

{ $$ = $1; }

However, in this case, $1 is the value of attribute_opt itself. As a
result, the value of attribute_opt is always NULL.

The following test code demonstrates inconsistent behavior.

int x __attribute__((__aligned__(4)));
int y __attribute__((__aligned__(4))) = 0;

The attribute is recorded only when followed by an initializer.

This commit adds the correct action to propagate the value of the
ATTRIBUTE_PHRASE token.

With this change, the attribute in the example above is consistently
recorded for both 'x' and 'y'.

[Before]

$ cat <<EOF | scripts/genksyms/genksyms -d
int x __attribute__((__aligned__(4)));
int y __attribute__((__aligned__(4))) = 0;
EOF
Defn for type0 x == <int x >
Defn for type0 y == <int y __attribute__ ( ( __aligned__ ( 4 ) ) ) >
Hash table occupancy 2/4096 = 0.000488281

[After]

$ cat <<EOF | scripts/genksyms/genksyms -d
int x __attribute__((__aligned__(4)));
int y __attribute__((__aligned__(4))) = 0;
EOF
Defn for type0 x == <int x __attribute__ ( ( __aligned__ ( 4 ) ) ) >
Defn for type0 y == <int y __attribute__ ( ( __aligned__ ( 4 ) ) ) >
Hash table occupancy 2/4096 = 0.000488281

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: restrict direct-declarator to take one parameter-type-list

Similar to the previous commit, this change makes the parser logic a
little more accurate.

Currently, genksyms accepts the follo

genksyms: restrict direct-declarator to take one parameter-type-list

Similar to the previous commit, this change makes the parser logic a
little more accurate.

Currently, genksyms accepts the following invalid code:

struct foo {
int (*callback)(int)(int)(int);
};

A direct-declarator should not recursively absorb multiple
( parameter-type-list ) constructs.

In the example above, (*callback) should be followed by at most one
(int).

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: restrict direct-abstract-declarator to take one parameter-type-list

While there is no more grammatical ambiguity in genksyms, the parser
logic is still inaccurate.

For example, genksyms a

genksyms: restrict direct-abstract-declarator to take one parameter-type-list

While there is no more grammatical ambiguity in genksyms, the parser
logic is still inaccurate.

For example, genksyms accepts the following invalid C code:

void my_func(int ()(int));

This should result in a syntax error because () cannot be reduced to
<direct-abstract-declarator>.

( <abstract-declarator> ) can be reduced, but <abstract-declarator>
must not be empty in the following grammar from K&R [1]:

<direct-abstract-declarator> ::= ( <abstract-declarator> )
| {<direct-abstract-declarator>}? [ {<constant-expression>}? ]
| {<direct-abstract-declarator>}? ( {<parameter-type-list>}? )

Furthermore, genksyms accepts the following weird code:

void my_func(int (*callback)(int)(int)(int));

The parser allows <direct-abstract-declarator> to recursively absorb
multiple ( {<parameter-type-list>}? ), but this behavior is incorrect.

In the example above, (*callback) should be followed by at most one
(int).

[1]: https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix last 3 shift/reduce conflicts

The genksyms parser has ambiguities in its grammar, which are currently
suppressed by a workaround in scripts/genksyms/Makefile.

Building genksyms with W

genksyms: fix last 3 shift/reduce conflicts

The genksyms parser has ambiguities in its grammar, which are currently
suppressed by a workaround in scripts/genksyms/Makefile.

Building genksyms with W=1 generates the following warnings:

YACC scripts/genksyms/parse.tab.[ch]
scripts/genksyms/parse.y: warning: 3 shift/reduce conflicts [-Wconflicts-sr]
scripts/genksyms/parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples

The ambiguity arises when decl_specifier_seq is followed by '(' because
the following two interpretations are possible:

- decl_specifier_seq direct_abstract_declarator '(' parameter_declaration_clause ')'
- decl_specifier_seq '(' abstract_declarator ')'

This issue occurs because the current parser allows an empty string to
be reduced to direct_abstract_declarator, which is incorrect.

K&R [1] explains the correct grammar:

<parameter-declaration> ::= {<declaration-specifier>}+ <declarator>
| {<declaration-specifier>}+ <abstract-declarator>
| {<declaration-specifier>}+

<abstract-declarator> ::= <pointer>
| <pointer> <direct-abstract-declarator>
| <direct-abstract-declarator>

<direct-abstract-declarator> ::= ( <abstract-declarator> )
| {<direct-abstract-declarator>}? [ {<constant-expression>}? ]
| {<direct-abstract-declarator>}? ( {<parameter-type-list>}? )

This commit resolves all remaining conflicts.

We need to consider the difference between the following two examples:

[Example 1] ( <abstract-declarator> ) can become <direct-abstract-declarator>

void my_func(int (foo));

... is equivalent to:

void my_func(int foo);

[Example 2] ( <parameter-type-list> ) can become <direct-abstract-declarator>

typedef int foo;
void my_func(int (foo));

... is equivalent to:

void my_func(int (*callback)(int));

Please note that the function declaration is identical in both examples,
but the preceding typedef creates the distinction. I introduced a new
term, open_paren, to enable the type lookup immediately after the '('
token. Without this, we cannot distinguish between [Example 1] and
[Example 2].

[1]: https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts

The genksyms parser has ambiguities in its grammar, which are currently
suppressed by a workaround in scripts/genksyms/Makefile.

genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts

The genksyms parser has ambiguities in its grammar, which are currently
suppressed by a workaround in scripts/genksyms/Makefile.

Building genksyms with W=1 generates the following warnings:

YACC scripts/genksyms/parse.tab.[ch]
scripts/genksyms/parse.y: warning: 9 shift/reduce conflicts [-Wconflicts-sr]
scripts/genksyms/parse.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr]
scripts/genksyms/parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples

The comment in the parser describes the current problem:

/* This wasn't really a typedef name but an identifier that
shadows one. */

Consider the following simple C code:

typedef int foo;
void my_func(foo foo) {}

In the function parameter list (foo foo), the first 'foo' is a type
specifier (typedef'ed as 'int'), while the second 'foo' is an identifier.

However, the lexer cannot distinguish between the two. Since 'foo' is
already typedef'ed, the lexer returns TYPE for both instances, instead
of returning IDENT for the second one.

To support shadowed identifiers, TYPE can be reduced to either a
simple_type_specifier or a direct_abstract_declarator, which creates
a grammatical ambiguity.

Without analyzing the grammar context, it is very difficult to resolve
this correctly.

This commit introduces a flag, dont_want_type_specifier, which allows
the parser to inform the lexer whether an identifier is expected. When
dont_want_type_specifier is true, the type lookup is suppressed, and
the lexer returns IDENT regardless of any preceding typedef.

After this commit, only 3 shift/reduce conflicts will remain.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: reduce type_qualifier directly to decl_specifier

A type_qualifier (const, volatile, etc.) is not a type_specifier.

According to K&R [1], a type-qualifier should be directly reduced to
a d

genksyms: reduce type_qualifier directly to decl_specifier

A type_qualifier (const, volatile, etc.) is not a type_specifier.

According to K&R [1], a type-qualifier should be directly reduced to
a declaration-specifier.

<declaration-specifier> ::= <storage-class-specifier>
| <type-specifier>
| <type-qualifier>

[1]: https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: rename cvar_qualifier to type_qualifier

I believe "cvar" stands for "Const, Volatile, Attribute, or Restrict".

This is called "type-qualifier" in K&R. [1]

Adopt this more generic naming.

genksyms: rename cvar_qualifier to type_qualifier

I believe "cvar" stands for "Const, Volatile, Attribute, or Restrict".

This is called "type-qualifier" in K&R. [1]

Adopt this more generic naming.

No functional changes are intended.

[1] https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: rename m_abstract_declarator to abstract_declarator

This is called "abstract-declarator" in K&R. [1]

I am not sure what "m_" stands for, but the name is clear enough
without it.

No funct

genksyms: rename m_abstract_declarator to abstract_declarator

This is called "abstract-declarator" in K&R. [1]

I am not sure what "m_" stands for, but the name is clear enough
without it.

No functional changes are intended.

[1] https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Nicolas Schier <[email protected]>

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genksyms: fix memory leak when the same symbol is read from *.symref file

When a symbol that is already registered is read again from *.symref
file, __add_symbol() removes the previous one from the

genksyms: fix memory leak when the same symbol is read from *.symref file

When a symbol that is already registered is read again from *.symref
file, __add_symbol() removes the previous one from the hash table without
freeing it.

[Test Case]

$ cat foo.c
#include <linux/export.h>
void foo(void);
void foo(void) {}
EXPORT_SYMBOL(foo);

$ cat foo.symref
foo void foo ( void )
foo void foo ( void )

When a symbol is removed from the hash table, it must be freed along
with its ->name and ->defn members. However, sym->name cannot be freed
because it is sometimes shared with node->string, but not always. If
sym->name and node->string share the same memory, free(sym->name) could
lead to a double-free bug.

To resolve this issue, always assign a strdup'ed string to sym->name.

Fixes: 64e6c1e12372 ("genksyms: track symbol checksum changes")
Signed-off-by: Masahiro Yamada <[email protected]>

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genksyms: fix memory leak when the same symbol is added from source

When a symbol that is already registered is added again, __add_symbol()
returns without freeing the symbol definition, making it u

genksyms: fix memory leak when the same symbol is added from source

When a symbol that is already registered is added again, __add_symbol()
returns without freeing the symbol definition, making it unreachable.

The following test cases demonstrate different memory leak points.

[Test Case 1]

Forward declaration with exactly the same definition

$ cat foo.c
#include <linux/export.h>
void foo(void);
void foo(void) {}
EXPORT_SYMBOL(foo);

[Test Case 2]

Forward declaration with a different definition (e.g. attribute)

$ cat foo.c
#include <linux/export.h>
void foo(void);
__attribute__((__section__(".ref.text"))) void foo(void) {}
EXPORT_SYMBOL(foo);

[Test Case 3]

Preserving an overridden symbol (compile with KBUILD_PRESERVE=1)

$ cat foo.c
#include <linux/export.h>
void foo(void);
void foo(void) { }
EXPORT_SYMBOL(foo);

$ cat foo.symref
override foo void foo ( int )

The memory leaks in Test Case 1 and 2 have existed since the introduction
of genksyms into the kernel tree. [1]

The memory leak in Test Case 3 was introduced by commit 5dae9a550a74
("genksyms: allow to ignore symbol checksum changes").

When multiple init_declarators are reduced to an init_declarator_list,
the decl_spec must be duplicated. Otherwise, the following Test Case 4
would result in a double-free bug.

[Test Case 4]

$ cat foo.c
#include <linux/export.h>

extern int foo, bar;

int foo, bar;
EXPORT_SYMBOL(foo);

In this case, 'foo' and 'bar' share the same decl_spec, 'int'. It must
be unshared before being passed to add_symbol().

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=46bd1da672d66ccd8a639d3c1f8a166048cca608

Fixes: 5dae9a550a74 ("genksyms: allow to ignore symbol checksum changes")
Signed-off-by: Masahiro Yamada <[email protected]>

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genksyms: Ignore module scoped _Static_assert()

The C11 _Static_assert() keyword may be used at module scope, and we
need to teach genksyms about it to not abort with an error. We currently
have a g

genksyms: Ignore module scoped _Static_assert()

The C11 _Static_assert() keyword may be used at module scope, and we
need to teach genksyms about it to not abort with an error. We currently
have a growing number of static_assert() (but also direct usage of
_Static_assert()) users at module scope:

git grep -E '^_Static_assert\(|^static_assert\(' | grep -v '^tools' | wc -l
135

More recently, when enabling CONFIG_MODVERSIONS with CONFIG_KCSAN, we
observe a number of warnings:

WARNING: modpost: EXPORT symbol "<..all kcsan symbols..>" [vmlinux] [...]

When running a preprocessed source through 'genksyms -w' a number of
syntax errors point at usage of static_assert()s. In the case of
kernel/kcsan/encoding.h, new static_assert()s had been introduced which
used expressions that appear to cause genksyms to not even be able to
recover from the syntax error gracefully (as it appears was the case
previously).

Therefore, make genksyms ignore all _Static_assert() and the contained
expression. With the fix, usage of _Static_assert() no longer cause
"syntax error" all over the kernel, and the above modpost warnings for
KCSAN are gone, too.

Signed-off-by: Marco Elver <[email protected]>
Acked-by: Nick Desaulniers <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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genksyms: convert to SPDX License Identifier for lex.l and parse.y

I used the C comment style (/* ... */) for the flex and bison files
as in Kconfig (scripts/kconfig/{lexer.l,parser.y})

Signed-off-

genksyms: convert to SPDX License Identifier for lex.l and parse.y

I used the C comment style (/* ... */) for the flex and bison files
as in Kconfig (scripts/kconfig/{lexer.l,parser.y})

Signed-off-by: Masahiro Yamada <[email protected]>

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genksyms: Teach parser about 128-bit built-in types

__uint128_t crops up in a few files that export symbols to modules, so
teach genksyms about it and the other GCC built-in 128-bit integer types
so

genksyms: Teach parser about 128-bit built-in types

__uint128_t crops up in a few files that export symbols to modules, so
teach genksyms about it and the other GCC built-in 128-bit integer types
so that we don't end up skipping the CRC generation for some symbols due
to the parser failing to spot them:

| WARNING: EXPORT symbol "kernel_neon_begin" [vmlinux] version
| generation failed, symbol will not be versioned.
| ld: arch/arm64/kernel/fpsimd.o: relocation R_AARCH64_ABS32 against
| `__crc_kernel_neon_begin' can not be used when making a shared
| object
| ld: arch/arm64/kernel/fpsimd.o:(.data+0x0): dangerous relocation:
| unsupported relocation

Reported-by: Arnd Bergmann <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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genksyms: Fix segfault with invalid declarations

Do not try to recover too early and segfault when parsing invalid
declarations such as

echo 'int (int);' | scripts/genksyms/genksyms
echo 'int a, (i

genksyms: Fix segfault with invalid declarations

Do not try to recover too early and segfault when parsing invalid
declarations such as

echo 'int (int);' | scripts/genksyms/genksyms
echo 'int a, (int);' | scripts/genksyms/genksyms
echo 'extern void *__inline_memcpy((void *), (const void *), (__kernel_size_t));' | scripts/genksyms/genksyms

The last one was a real-life bug with
include/asm-generic/asm-prototypes.h on x86_64.

Reported-and-tested-by: Borislav Petkov <[email protected]>
Signed-off-by: Michal Marek <[email protected]>

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kbuild/genksyms: handle va_list type

genksyms currently does not handle va_list. Add the __builtin_va_list
keyword as a type. This reduces the amount of syntax errors thrown,
but so far no export sy

kbuild/genksyms: handle va_list type

genksyms currently does not handle va_list. Add the __builtin_va_list
keyword as a type. This reduces the amount of syntax errors thrown,
but so far no export symbol has a type with a va_list argument, so
there is currently no bug in the end result.

Note: this patch does not regenerate shipped parser files.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michal Marek <[email protected]>

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genksyms: Duplicate function pointer type definitions segfault

I noticed that genksyms will segfault when it sees duplicate function
pointer type declaration when I placed the same function pointer

genksyms: Duplicate function pointer type definitions segfault

I noticed that genksyms will segfault when it sees duplicate function
pointer type declaration when I placed the same function pointer
definition in two separate headers in a local branch as an intermediate
step of some refactoring. This can be reproduced by piping the following
minimal test case into `genksyms -r /dev/null` or alternatively, putting
it into a C file attempting a build:

typedef int (*f)();
typedef int (*f)();

Attaching gdb to genksyms to understand this failure is useless without
changing CFLAGS to emit debuginfo. Once you have debuginfo, you will
find that the failure is that `char *s` was NULL and the program
executed `while(*s)`. At which point, further debugging requires
familiarity with compiler front end / parser development.

What happens is that flex identifies the first instance of the token "f"
as IDENT and the yacc parser adds it to the symbol table. On the second
instance, flex will identify "f" as TYPE, which triggers an error case
in the yacc parser. Given that TYPE would have been IDENT had it not
been in the symbol table, the the segmentaion fault could be avoided by
treating TYPE as IDENT in the affected rule.

Some might consider placing identical function pointer type declarations
in different headers to be poor style might consider a failure to be
beneficial. However, failing through a segmentation fault makes the
cause non-obvious and can waste the time of anyone who encounters it.

Signed-off-by: Richard Yao <[email protected]>
Acked-by: Madhuri Yechuri <[email protected]>
Signed-off-by: Michal Marek <[email protected]>

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genksyms: fix typeof() handling

Recent increased use of typeof() throughout the tree resulted in a
number of symbols (25 in a typical distro config of ours) not getting a
proper CRC calculated for t

genksyms: fix typeof() handling

Recent increased use of typeof() throughout the tree resulted in a
number of symbols (25 in a typical distro config of ours) not getting a
proper CRC calculated for them anymore, due to the parser in genksyms
not coping with several of these uses (interestingly in the majority of
[if not all] cases the problem is due to the use of typeof() in code
preceding a certain export, not in the declaration/definition of the
exported function/object itself; I wasn't able to find a way to address
this more general parser shortcoming).

The use of parameter_declaration is a little more relaxed than would be
ideal (permitting not just a bare type specification, but also one with
identifier), but since the same code is being passed through an actual
compiler, there's no apparent risk of allowing through any broken code.

Otoh using parameter_declaration instead of the ad hoc
"decl_specifier_seq '*'" / "decl_specifier_seq" pair allows all types to
be handled rather than just plain ones and pointers to plain ones.

Signed-off-by: Jan Beulich <[email protected]>
Cc: Michal Marek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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