| Message ID | 20230315171550.1551603-1-deso@posteo.net (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6cb9430be1471d631e1b6b138e6d26657a9caa81 |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] libbpf: Ignore warnings about "inefficient alignment" | expand |
For what it's worth, I was unable to reproduce the original issue, locally and in CI. So this is a best guess at a fix based on the suggestion provided in the linked report. Thanks, Daniel On Wed, Mar 15, 2023 at 05:15:50PM +0000, Daniel Müller wrote: > Some consumers of libbpf compile the code base with different warnings > enabled. In a report for perf, for example, -Wpacked was set which > caused warnings about "inefficient alignment" to be emitted on a subset > of supported architectures. > With this change we silence specifically those warnings, as we > intentionally worked with packed structs. > > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> > Link: https://lore.kernel.org/bpf/CA+G9fYtBnwxAWXi2+GyNByApxnf_DtP1-6+_zOKAdJKnJBexjg@mail.gmail.com/ > Fixes: 1eebcb60633f ("libbpf: Implement basic zip archive parsing support") > Signed-off-by: Daniel Müller <deso@posteo.net> > --- > tools/lib/bpf/zip.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/tools/lib/bpf/zip.c b/tools/lib/bpf/zip.c > index f561aa..3f26d62 100644 > --- a/tools/lib/bpf/zip.c > +++ b/tools/lib/bpf/zip.c > @@ -16,6 +16,10 @@ > #include "libbpf_internal.h" > #include "zip.h" > > +#pragma GCC diagnostic push > +#pragma GCC diagnostic ignored "-Wpacked" > +#pragma GCC diagnostic ignored "-Wattributes" > + > /* Specification of ZIP file format can be found here: > * https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT > * For a high level overview of the structure of a ZIP file see > @@ -119,6 +123,8 @@ struct local_file_header { > __u16 extra_field_length; > } __attribute__((packed)); > > +#pragma GCC diagnostic pop > + > struct zip_archive { > void *data; > __u32 size; > -- > 2.34.1 >
Hello: This patch was applied to bpf/bpf-next.git (master) by Daniel Borkmann <daniel@iogearbox.net>: On Wed, 15 Mar 2023 17:15:50 +0000 you wrote: > Some consumers of libbpf compile the code base with different warnings > enabled. In a report for perf, for example, -Wpacked was set which > caused warnings about "inefficient alignment" to be emitted on a subset > of supported architectures. > With this change we silence specifically those warnings, as we > intentionally worked with packed structs. > > [...] Here is the summary with links: - [bpf-next] libbpf: Ignore warnings about "inefficient alignment" https://git.kernel.org/bpf/bpf-next/c/6cb9430be147 You are awesome, thank you!
diff --git a/tools/lib/bpf/zip.c b/tools/lib/bpf/zip.c index f561aa..3f26d62 100644 --- a/tools/lib/bpf/zip.c +++ b/tools/lib/bpf/zip.c @@ -16,6 +16,10 @@ #include "libbpf_internal.h" #include "zip.h" +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wpacked" +#pragma GCC diagnostic ignored "-Wattributes" + /* Specification of ZIP file format can be found here: * https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT * For a high level overview of the structure of a ZIP file see @@ -119,6 +123,8 @@ struct local_file_header { __u16 extra_field_length; } __attribute__((packed)); +#pragma GCC diagnostic pop + struct zip_archive { void *data; __u32 size;
Some consumers of libbpf compile the code base with different warnings enabled. In a report for perf, for example, -Wpacked was set which caused warnings about "inefficient alignment" to be emitted on a subset of supported architectures. With this change we silence specifically those warnings, as we intentionally worked with packed structs. Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Link: https://lore.kernel.org/bpf/CA+G9fYtBnwxAWXi2+GyNByApxnf_DtP1-6+_zOKAdJKnJBexjg@mail.gmail.com/ Fixes: 1eebcb60633f ("libbpf: Implement basic zip archive parsing support") Signed-off-by: Daniel Müller <deso@posteo.net> --- tools/lib/bpf/zip.c | 6 ++++++ 1 file changed, 6 insertions(+)