* [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array @ 2020-08-20 16:05 Zhao Heming 2020-08-20 16:08 ` heming.zhao 2020-08-26 5:18 ` heming.zhao 0 siblings, 2 replies; 7+ messages in thread From: Zhao Heming @ 2020-08-20 16:05 UTC (permalink / raw) To: linux-lvm; +Cc: mcsontos, Zhao Heming this patch makes gcc happy with compiling option: [-Wstringop-overflow=] Signed-off-by: Zhao Heming <heming.zhao@suse.com> --- device_mapper/libdm-common.c | 2 +- lib/activate/fs.c | 2 +- libdm/libdm-common.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c index bc691d6..3627457 100644 --- a/device_mapper/libdm-common.c +++ b/device_mapper/libdm-common.c @@ -1445,7 +1445,7 @@ struct node_op_parms { char *old_name; int warn_if_udev_failed; unsigned rely_on_udev; - char names[0]; + char names[]; }; static void _store_str(char **pos, char **ptr, const char *str) diff --git a/lib/activate/fs.c b/lib/activate/fs.c index b2c99fc..96f7df6 100644 --- a/lib/activate/fs.c +++ b/lib/activate/fs.c @@ -313,7 +313,7 @@ struct fs_op_parms { char *lv_name; char *dev; char *old_lv_name; - char names[0]; + char names[]; }; static void _store_str(char **pos, char **ptr, const char *str) diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c index d75c704..d587c32 100644 --- a/libdm/libdm-common.c +++ b/libdm/libdm-common.c @@ -1443,7 +1443,7 @@ struct node_op_parms { char *old_name; int warn_if_udev_failed; unsigned rely_on_udev; - char names[0]; + char names[]; }; static void _store_str(char **pos, char **ptr, const char *str) -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-08-20 16:05 [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array Zhao Heming @ 2020-08-20 16:08 ` heming.zhao 2020-08-26 5:18 ` heming.zhao 1 sibling, 0 replies; 7+ messages in thread From: heming.zhao @ 2020-08-20 16:08 UTC (permalink / raw) To: linux-lvm; +Cc: mcsontos more info or discussion with this patch. I met this compiling issue when I was creating openSUSE package. I'm a little confused & wonder why Fedora can pass this gcc warning. On 8/21/20 12:05 AM, Zhao Heming wrote: > this patch makes gcc happy with compiling option: [-Wstringop-overflow=] > > Signed-off-by: Zhao Heming <heming.zhao@suse.com> > --- > device_mapper/libdm-common.c | 2 +- > lib/activate/fs.c | 2 +- > libdm/libdm-common.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c > index bc691d6..3627457 100644 > --- a/device_mapper/libdm-common.c > +++ b/device_mapper/libdm-common.c ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-08-20 16:05 [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array Zhao Heming 2020-08-20 16:08 ` heming.zhao @ 2020-08-26 5:18 ` heming.zhao 2020-08-28 19:32 ` Zdenek Kabelac 1 sibling, 1 reply; 7+ messages in thread From: heming.zhao @ 2020-08-26 5:18 UTC (permalink / raw) To: linux-lvm; +Cc: mcsontos ping. @Marian & other maintainers On 8/21/20 12:05 AM, Zhao Heming wrote: > this patch makes gcc happy with compiling option: [-Wstringop-overflow=] > > Signed-off-by: Zhao Heming <heming.zhao@suse.com> > --- > device_mapper/libdm-common.c | 2 +- > lib/activate/fs.c | 2 +- > libdm/libdm-common.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c > index bc691d6..3627457 100644 > --- a/device_mapper/libdm-common.c > +++ b/device_mapper/libdm-common.c > @@ -1445,7 +1445,7 @@ struct node_op_parms { > char *old_name; > int warn_if_udev_failed; > unsigned rely_on_udev; > - char names[0]; > + char names[]; > }; > > static void _store_str(char **pos, char **ptr, const char *str) > diff --git a/lib/activate/fs.c b/lib/activate/fs.c > index b2c99fc..96f7df6 100644 > --- a/lib/activate/fs.c > +++ b/lib/activate/fs.c > @@ -313,7 +313,7 @@ struct fs_op_parms { > char *lv_name; > char *dev; > char *old_lv_name; > - char names[0]; > + char names[]; > }; > > static void _store_str(char **pos, char **ptr, const char *str) > diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c > index d75c704..d587c32 100644 > --- a/libdm/libdm-common.c > +++ b/libdm/libdm-common.c > @@ -1443,7 +1443,7 @@ struct node_op_parms { > char *old_name; > int warn_if_udev_failed; > unsigned rely_on_udev; > - char names[0]; > + char names[]; > }; > > static void _store_str(char **pos, char **ptr, const char *str) > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-08-26 5:18 ` heming.zhao @ 2020-08-28 19:32 ` Zdenek Kabelac 2020-08-29 3:11 ` heming.zhao 0 siblings, 1 reply; 7+ messages in thread From: Zdenek Kabelac @ 2020-08-28 19:32 UTC (permalink / raw) To: LVM general discussion and development, heming.zhao [-- Attachment #1: Type: text/plain, Size: 1306 bytes --] Dne 26. 08. 20 v 7:18 heming.zhao@suse.com napsal(a): > ping. > > @Marian & other maintainers > > > On 8/21/20 12:05 AM, Zhao Heming wrote: >> this patch makes gcc happy with compiling option: [-Wstringop-overflow=] >> >> Signed-off-by: Zhao Heming <heming.zhao@suse.com> >> --- >> device_mapper/libdm-common.c | 2 +- >> lib/activate/fs.c | 2 +- >> libdm/libdm-common.c | 2 +- >> 3 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c >> index bc691d6..3627457 100644 >> --- a/device_mapper/libdm-common.c >> +++ b/device_mapper/libdm-common.c >> @@ -1445,7 +1445,7 @@ struct node_op_parms { >> char *old_name; >> int warn_if_udev_failed; >> unsigned rely_on_udev; >> - char names[0]; >> + char names[]; >> }; >> Hi Here I don't see much problem with patch itself - except it seems to be somewhat mysterious. Lvm2 is not strict ISO C compilable - there are far to many other things which would need to be fixed - thus flexible arrays shouldn't be an issue. I'm curious why these 3 were important in your case - while other 26 appearances passed for you just fine (see attachment). So can you paste what sort of gcc problem do you actually try to solve ? Regards Zdenek [-- Attachment #2: gcc-change-zero-sized-array-to-fexlible-array-II.patch --] [-- Type: text/x-patch, Size: 8301 bytes --] From: Zdenek Kabelac <zkabelac@redhat.com> Date: Fri, 28 Aug 2020 19:15:01 +0200 Subject: gcc: change zero-sized array to fexlible array II --- base/data-struct/hash.c | 2 +- base/data-struct/radix-tree-adaptive.c | 2 +- daemons/lvmlockd/lvmlockd-internal.h | 2 +- device_mapper/all.h | 6 +++--- device_mapper/misc/dm-ioctl.h | 8 ++++---- lib/device/dev-cache.c | 2 +- lib/format_text/layout.h | 6 +++--- lib/label/label.c | 2 +- lib/metadata/lv_manip.c | 2 +- libdm/datastruct/hash.c | 2 +- libdm/libdevmapper.h | 6 +++--- libdm/libdm-stats.c | 2 +- libdm/misc/dm-ioctl.h | 8 ++++---- tools/tools.h | 2 +- 14 files changed, 26 insertions(+), 26 deletions(-) diff --git a/base/data-struct/hash.c b/base/data-struct/hash.c index 0a0541d2e..5ef5ed276 100644 --- a/base/data-struct/hash.c +++ b/base/data-struct/hash.c @@ -22,7 +22,7 @@ struct dm_hash_node { void *data; unsigned data_len; unsigned keylen; - char key[0]; + char key[]; }; struct dm_hash_table { diff --git a/base/data-struct/radix-tree-adaptive.c b/base/data-struct/radix-tree-adaptive.c index b9ba4179f..3a46cc14b 100644 --- a/base/data-struct/radix-tree-adaptive.c +++ b/base/data-struct/radix-tree-adaptive.c @@ -47,7 +47,7 @@ struct value_chain { struct prefix_chain { struct value child; unsigned len; - uint8_t prefix[0]; + uint8_t prefix[]; }; struct node4 { diff --git a/daemons/lvmlockd/lvmlockd-internal.h b/daemons/lvmlockd/lvmlockd-internal.h index 191c44926..14bdfeed0 100644 --- a/daemons/lvmlockd/lvmlockd-internal.h +++ b/daemons/lvmlockd/lvmlockd-internal.h @@ -158,7 +158,7 @@ struct resource { struct list_head locks; struct list_head actions; char lv_args[MAX_ARGS+1]; - char lm_data[0]; /* lock manager specific data */ + char lm_data[]; /* lock manager specific data */ }; #define LD_LF_PERSISTENT 0x00000001 diff --git a/device_mapper/all.h b/device_mapper/all.h index c3c6219e3..ace3b69a0 100644 --- a/device_mapper/all.h +++ b/device_mapper/all.h @@ -164,20 +164,20 @@ struct dm_info { struct dm_deps { uint32_t count; uint32_t filler; - uint64_t device[0]; + uint64_t device[]; }; struct dm_names { uint64_t dev; uint32_t next; /* Offset to next struct from start of this struct */ - char name[0]; + char name[]; }; struct dm_versions { uint32_t next; /* Offset to next struct from start of this struct */ uint32_t version[3]; - char name[0]; + char name[]; }; int dm_get_library_version(char *version, size_t size); diff --git a/device_mapper/misc/dm-ioctl.h b/device_mapper/misc/dm-ioctl.h index cc2374c36..49954a764 100644 --- a/device_mapper/misc/dm-ioctl.h +++ b/device_mapper/misc/dm-ioctl.h @@ -183,7 +183,7 @@ struct dm_target_spec { struct dm_target_deps { uint32_t count; /* Array size */ uint32_t padding; /* unused */ - uint64_t dev[0]; /* out */ + uint64_t dev[]; /* out */ }; /* @@ -193,7 +193,7 @@ struct dm_name_list { uint64_t dev; uint32_t next; /* offset to the next record from the _start_ of this */ - char name[0]; + char name[]; }; /* @@ -203,7 +203,7 @@ struct dm_target_versions { uint32_t next; uint32_t version[3]; - char name[0]; + char name[]; }; /* @@ -212,7 +212,7 @@ struct dm_target_versions { struct dm_target_msg { uint64_t sector; /* Device sector */ - char message[0]; + char message[]; }; /* diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c index c3f7c49be..d4e2658aa 100644 --- a/lib/device/dev-cache.c +++ b/lib/device/dev-cache.c @@ -35,7 +35,7 @@ struct dev_iter { struct dir_list { struct dm_list list; - char dir[0]; + char dir[]; }; static struct { diff --git a/lib/format_text/layout.h b/lib/format_text/layout.h index c3dfe8e7a..df7ed3a78 100644 --- a/lib/format_text/layout.h +++ b/lib/format_text/layout.h @@ -33,7 +33,7 @@ struct pv_header_extension { uint32_t version; uint32_t flags; /* NULL-terminated list of bootloader areas */ - struct disk_locn bootloader_areas_xl[0]; + struct disk_locn bootloader_areas_xl[]; } __attribute__ ((packed)); /* Fields with the suffix _xl should be xlate'd wherever they appear */ @@ -46,7 +46,7 @@ struct pv_header { /* NULL-terminated list of data areas followed by */ /* NULL-terminated list of metadata area headers */ - struct disk_locn disk_areas_xl[0]; /* Two lists */ + struct disk_locn disk_areas_xl[]; /* Two lists */ } __attribute__ ((packed)); /* @@ -76,7 +76,7 @@ struct mda_header { uint64_t start; /* Absolute start byte of mda_header */ uint64_t size; /* Size of metadata area */ - struct raw_locn raw_locns[0]; /* NULL-terminated list */ + struct raw_locn raw_locns[]; /* NULL-terminated list */ } __attribute__ ((packed)); struct mda_header *raw_read_mda_header(const struct format_type *fmt, diff --git a/lib/label/label.c b/lib/label/label.c index 4d369d4f1..8e68f9303 100644 --- a/lib/label/label.c +++ b/lib/label/label.c @@ -43,7 +43,7 @@ struct labeller_i { struct dm_list list; struct labeller *l; - char name[0]; + char name[]; }; static struct dm_list _labellers; diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c index c47ec72e2..95ca2df39 100644 --- a/lib/metadata/lv_manip.c +++ b/lib/metadata/lv_manip.c @@ -1798,7 +1798,7 @@ struct alloc_handle { * Contains area_count lists of areas allocated to data stripes * followed by log_area_count lists of areas allocated to log stripes. */ - struct dm_list alloced_areas[0]; + struct dm_list alloced_areas[]; }; /* diff --git a/libdm/datastruct/hash.c b/libdm/datastruct/hash.c index 4c940039a..726347ea2 100644 --- a/libdm/datastruct/hash.c +++ b/libdm/datastruct/hash.c @@ -20,7 +20,7 @@ struct dm_hash_node { void *data; unsigned data_len; unsigned keylen; - char key[0]; + char key[]; }; struct dm_hash_table { diff --git a/libdm/libdevmapper.h b/libdm/libdevmapper.h index e9b140563..059b96f0b 100644 --- a/libdm/libdevmapper.h +++ b/libdm/libdevmapper.h @@ -165,20 +165,20 @@ struct dm_info { struct dm_deps { uint32_t count; uint32_t filler; - uint64_t device[0]; + uint64_t device[]; }; struct dm_names { uint64_t dev; uint32_t next; /* Offset to next struct from start of this struct */ - char name[0]; + char name[]; }; struct dm_versions { uint32_t next; /* Offset to next struct from start of this struct */ uint32_t version[3]; - char name[0]; + char name[]; }; int dm_get_library_version(char *version, size_t size); diff --git a/libdm/libdm-stats.c b/libdm/libdm-stats.c index 5379bed5e..f8d79d807 100644 --- a/libdm/libdm-stats.c +++ b/libdm/libdm-stats.c @@ -65,7 +65,7 @@ struct dm_histogram { const struct dm_stats_region *region; uint64_t sum; /* Sum of histogram bin counts. */ int nr_bins; /* Number of histogram bins assigned. */ - struct dm_histogram_bin bins[0]; + struct dm_histogram_bin bins[]; }; /* diff --git a/libdm/misc/dm-ioctl.h b/libdm/misc/dm-ioctl.h index 52a7a93d1..55dee2148 100644 --- a/libdm/misc/dm-ioctl.h +++ b/libdm/misc/dm-ioctl.h @@ -183,7 +183,7 @@ struct dm_target_spec { struct dm_target_deps { uint32_t count; /* Array size */ uint32_t padding; /* unused */ - uint64_t dev[0]; /* out */ + uint64_t dev[]; /* out */ }; /* @@ -193,7 +193,7 @@ struct dm_name_list { uint64_t dev; uint32_t next; /* offset to the next record from the _start_ of this */ - char name[0]; + char name[]; }; /* @@ -203,7 +203,7 @@ struct dm_target_versions { uint32_t next; uint32_t version[3]; - char name[0]; + char name[]; }; /* @@ -212,7 +212,7 @@ struct dm_target_versions { struct dm_target_msg { uint64_t sector; /* Device sector */ - char message[0]; + char message[]; }; /* diff --git a/tools/tools.h b/tools/tools.h index 4b944e2fd..befff5708 100644 --- a/tools/tools.h +++ b/tools/tools.h @@ -110,7 +110,7 @@ struct arg_values { struct arg_value_group_list { struct dm_list list; uint32_t prio; - struct arg_values arg_values[0]; + struct arg_values arg_values[]; }; #define PERMITTED_READ_ONLY 0x00000002 -- 2.27.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-08-28 19:32 ` Zdenek Kabelac @ 2020-08-29 3:11 ` heming.zhao 2020-09-02 15:22 ` Zdenek Kabelac 0 siblings, 1 reply; 7+ messages in thread From: heming.zhao @ 2020-08-29 3:11 UTC (permalink / raw) To: Zdenek Kabelac, LVM general discussion and development; +Cc: dcermak On 8/29/20 3:32 AM, Zdenek Kabelac wrote: > Dne 26. 08. 20 v 7:18 heming.zhao@suse.com napsal(a): >> ping. >> >> @Marian & other maintainers >> >> >> On 8/21/20 12:05 AM, Zhao Heming wrote: >>> this patch makes gcc happy with compiling option: [-Wstringop-overflow=] >>> >>> Signed-off-by: Zhao Heming <heming.zhao@suse.com> >>> --- >>> �� device_mapper/libdm-common.c | 2 +- >>> �� lib/activate/fs.c����������� | 2 +- >>> �� libdm/libdm-common.c�������� | 2 +- >>> �� 3 files changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c >>> index bc691d6..3627457 100644 >>> --- a/device_mapper/libdm-common.c >>> +++ b/device_mapper/libdm-common.c >>> @@ -1445,7 +1445,7 @@ struct node_op_parms { >>> ������ char *old_name; >>> ������ int warn_if_udev_failed; >>> ������ unsigned rely_on_udev; >>> -��� char names[0]; >>> +��� char names[]; >>> �� }; > > > Hi > > Here I don't see much problem with patch itself - except it seems to be somewhat mysterious. Lvm2 is not strict ISO C compilable - there are far to many other things which would need to be fixed - thus flexible arrays shouldn't be an issue. > > I'm curious why these 3 were important in your case - while other 26 appearances passed for you just fine (see attachment). > > So can you paste what sort of gcc problem do you actually try to solve ? > > Regards > > Zdenek These 3 zero-sized array blocked me to create lvm2 package for opensuse tumbleweed. Opensuse uses OBS (open build service: https://openbuildservice.org/) to create rpm packages. In my eyes, the OBS is black-box, it only showed these 3 warning and stopped building work. So I filed patch only about these 3 places. the build error just related with [-Wstringop-overflow=] ``` [ 72s] In function 'strcpy', [ 72s] inlined from '_store_str' at device_mapper/libdm-common.c:1453:2, [ 72s] inlined from '_stack_node_op' at device_mapper/libdm-common.c:1589:2: [ 72s] /usr/include/bits/string_fortified.h:90:10: warning: '__builtin_strcpy' writing 1 or more bytes into a region of size 0 overflows the destination [-Wstringop-overflow=] [ 72s] 90 | return __builtin___strcpy_chk (__dest, __src, __bos (__dest)); ``` thanks, heming ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-08-29 3:11 ` heming.zhao @ 2020-09-02 15:22 ` Zdenek Kabelac 2020-09-03 14:58 ` heming.zhao 0 siblings, 1 reply; 7+ messages in thread From: Zdenek Kabelac @ 2020-09-02 15:22 UTC (permalink / raw) To: LVM general discussion and development, heming.zhao; +Cc: dcermak Dne 29. 08. 20 v 5:11 heming.zhao@suse.com napsal(a): > > These 3 zero-sized array blocked me to create lvm2 package for opensuse tumbleweed. > Opensuse uses OBS (open build service: https://openbuildservice.org/) to create rpm packages. > In my eyes, the OBS is black-box, it only showed these 3 warning and stopped building work. > So I filed patch only about these 3 places. > > the build error just related with [-Wstringop-overflow=] > ``` > [ 72s] In function 'strcpy', > [ 72s] inlined from '_store_str' at device_mapper/libdm-common.c:1453:2, > [ 72s] inlined from '_stack_node_op' at device_mapper/libdm-common.c:1589:2: > [ 72s] /usr/include/bits/string_fortified.h:90:10: warning: '__builtin_strcpy' writing 1 or more bytes into a region of size 0 overflows the destination [-Wstringop-overflow=] > [ 72s] 90 | return __builtin___strcpy_chk (__dest, __src, __bos (__dest)); > ``` > Hi So patches have've been pushed into master HEAD - so maybe you can try to validate whether this changes things for your builder server - we can then consider backporting to stable-2.0 branch. Regards Zdenek ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array 2020-09-02 15:22 ` Zdenek Kabelac @ 2020-09-03 14:58 ` heming.zhao 0 siblings, 0 replies; 7+ messages in thread From: heming.zhao @ 2020-09-03 14:58 UTC (permalink / raw) To: Zdenek Kabelac, LVM general discussion and development; +Cc: dcermak Hello Zdenek, For dependency, I patched below 3 patches, the opensuse tumbleweed building completed successfully ``` ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-09-03 14:58 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-08-20 16:05 [linux-lvm] [PATCH] gcc: change zero-sized array to fexlible array Zhao Heming 2020-08-20 16:08 ` heming.zhao 2020-08-26 5:18 ` heming.zhao 2020-08-28 19:32 ` Zdenek Kabelac 2020-08-29 3:11 ` heming.zhao 2020-09-02 15:22 ` Zdenek Kabelac 2020-09-03 14:58 ` heming.zhao
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