[v3,00/16] support __packed struct

Message

Luc Van Oostenryck Dec. 31, 2020, 10:10 a.m. UTC

During parsing, Sparse recognizes the attribute 'packed' but this
attribute is otherwise ignored for several reasons:
1) the attribute in 'struct __attr { ... }' is wrongly handled as
   belonging to the whole declaration but it should belong to the type,
2) the attribute in 'struct <name> { ... } __attr;' is simply ignored,
3) the layout of packed bitfields need special care.

This series contains 2 parts:
1) handling of type attributes
2) correct layout of packed structs, including packed bitfields.


This series is also available for review and testing at:
  git://git.kernel.org/pub/scm/devel/sparse/sparse-dev.git packed-v3


Changes since v2 (all thanks to Ramsay Jones):
* correct several typos
* add an explanation for one of the test
* avoid sizeof() in tests where the size is constrained to some fixed value
* remove a redundency in a test (struct sb identical to struct sa)
* reformulate the commit message for apply_ctype()'s arguments reversal
* tweak the not-so-1-to-1 code movement
* fix the truncated commit message of the last patch

Changes since v1:
* fix layout of packed bitfields


Luc Van Oostenryck (16):
  add testcases for dubious enum values
  add testcases for exotic enum values
  add testcases for enum attributes
  add testcases for type attributes
  add testcases for packed structures
  add testcases for packed bitfields
  apply_ctype: use self-explanatory argument name
  apply_ctype: reverse the order of arguments
  apply_ctype: move up its declaration
  struct-attr: prepare to handle attributes at the end of struct
    definitions (1)
  struct-attr: prepare to handle attributes at the end of struct
    definitions (2)
  struct-attr: prepare to handle attributes at the end of struct
    definitions (3)
  struct-attr: fix type attribute like 'struct __attr { ... }'
  struct-attr: fix: do not ignore struct/union/enum type attributes
  packed: no out-of-bound access of packed bitfields
  packed: add support for __packed struct

 Documentation/TODO.md             |  3 --
 linearize.c                       | 13 +++++-
 parse.c                           | 78 ++++++++++++++++---------------
 symbol.c                          | 12 +++--
 symbol.h                          |  2 +
 validation/enum-type-dubious.c    | 18 +++++++
 validation/enum-type-exotic.c     | 28 +++++++++++
 validation/packed-bitfield0.c     | 58 +++++++++++++++++++++++
 validation/packed-bitfield1.c     | 27 +++++++++++
 validation/packed-bitfield2.c     | 15 ++++++
 validation/packed-bitfield3.c     | 28 +++++++++++
 validation/packed-bitfield4.c     | 18 +++++++
 validation/packed-bitfield5.c     | 20 ++++++++
 validation/packed-deref0.c        | 23 +++++++++
 validation/packed-struct.c        | 32 +++++++++++++
 validation/parsing/enum-attr.c    | 29 ++++++++++++
 validation/type-attribute-align.c | 19 ++++++++
 validation/type-attribute-as.c    | 33 +++++++++++++
 validation/type-attribute-mod.c   | 21 +++++++++
 validation/type-attribute-qual.c  | 15 ++++++
 20 files changed, 447 insertions(+), 45 deletions(-)
 create mode 100644 validation/enum-type-dubious.c
 create mode 100644 validation/enum-type-exotic.c
 create mode 100644 validation/packed-bitfield0.c
 create mode 100644 validation/packed-bitfield1.c
 create mode 100644 validation/packed-bitfield2.c
 create mode 100644 validation/packed-bitfield3.c
 create mode 100644 validation/packed-bitfield4.c
 create mode 100644 validation/packed-bitfield5.c
 create mode 100644 validation/packed-deref0.c
 create mode 100644 validation/packed-struct.c
 create mode 100644 validation/parsing/enum-attr.c
 create mode 100644 validation/type-attribute-align.c
 create mode 100644 validation/type-attribute-as.c
 create mode 100644 validation/type-attribute-mod.c
 create mode 100644 validation/type-attribute-qual.c

Comments

Ramsay Jones Dec. 31, 2020, 3:30 p.m. UTC | #1

On 31/12/2020 10:10, Luc Van Oostenryck wrote:
> During parsing, Sparse recognizes the attribute 'packed' but this
> attribute is otherwise ignored for several reasons:
> 1) the attribute in 'struct __attr { ... }' is wrongly handled as
>    belonging to the whole declaration but it should belong to the type,
> 2) the attribute in 'struct <name> { ... } __attr;' is simply ignored,
> 3) the layout of packed bitfields need special care.
> 
> This series contains 2 parts:
> 1) handling of type attributes
> 2) correct layout of packed structs, including packed bitfields.
> 
> 
> This series is also available for review and testing at:
>   git://git.kernel.org/pub/scm/devel/sparse/sparse-dev.git packed-v3
> 
> 
> Changes since v2 (all thanks to Ramsay Jones):
> * correct several typos
> * add an explanation for one of the test
> * avoid sizeof() in tests where the size is constrained to some fixed value
> * remove a redundency in a test (struct sb identical to struct sa)
> * reformulate the commit message for apply_ctype()'s arguments reversal
> * tweak the not-so-1-to-1 code movement
> * fix the truncated commit message of the last patch

This all LGTM. Thanks!

ATB,
Ramsay Jones

> 
> Changes since v1:
> * fix layout of packed bitfields
> 
> 
> Luc Van Oostenryck (16):
>   add testcases for dubious enum values
>   add testcases for exotic enum values
>   add testcases for enum attributes
>   add testcases for type attributes
>   add testcases for packed structures
>   add testcases for packed bitfields
>   apply_ctype: use self-explanatory argument name
>   apply_ctype: reverse the order of arguments
>   apply_ctype: move up its declaration
>   struct-attr: prepare to handle attributes at the end of struct
>     definitions (1)
>   struct-attr: prepare to handle attributes at the end of struct
>     definitions (2)
>   struct-attr: prepare to handle attributes at the end of struct
>     definitions (3)
>   struct-attr: fix type attribute like 'struct __attr { ... }'
>   struct-attr: fix: do not ignore struct/union/enum type attributes
>   packed: no out-of-bound access of packed bitfields
>   packed: add support for __packed struct
> 
>  Documentation/TODO.md             |  3 --
>  linearize.c                       | 13 +++++-
>  parse.c                           | 78 ++++++++++++++++---------------
>  symbol.c                          | 12 +++--
>  symbol.h                          |  2 +
>  validation/enum-type-dubious.c    | 18 +++++++
>  validation/enum-type-exotic.c     | 28 +++++++++++
>  validation/packed-bitfield0.c     | 58 +++++++++++++++++++++++
>  validation/packed-bitfield1.c     | 27 +++++++++++
>  validation/packed-bitfield2.c     | 15 ++++++
>  validation/packed-bitfield3.c     | 28 +++++++++++
>  validation/packed-bitfield4.c     | 18 +++++++
>  validation/packed-bitfield5.c     | 20 ++++++++
>  validation/packed-deref0.c        | 23 +++++++++
>  validation/packed-struct.c        | 32 +++++++++++++
>  validation/parsing/enum-attr.c    | 29 ++++++++++++
>  validation/type-attribute-align.c | 19 ++++++++
>  validation/type-attribute-as.c    | 33 +++++++++++++
>  validation/type-attribute-mod.c   | 21 +++++++++
>  validation/type-attribute-qual.c  | 15 ++++++
>  20 files changed, 447 insertions(+), 45 deletions(-)
>  create mode 100644 validation/enum-type-dubious.c
>  create mode 100644 validation/enum-type-exotic.c
>  create mode 100644 validation/packed-bitfield0.c
>  create mode 100644 validation/packed-bitfield1.c
>  create mode 100644 validation/packed-bitfield2.c
>  create mode 100644 validation/packed-bitfield3.c
>  create mode 100644 validation/packed-bitfield4.c
>  create mode 100644 validation/packed-bitfield5.c
>  create mode 100644 validation/packed-deref0.c
>  create mode 100644 validation/packed-struct.c
>  create mode 100644 validation/parsing/enum-attr.c
>  create mode 100644 validation/type-attribute-align.c
>  create mode 100644 validation/type-attribute-as.c
>  create mode 100644 validation/type-attribute-mod.c
>  create mode 100644 validation/type-attribute-qual.c
>