| Message ID | 20210105153944.951019-1-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] tools/resolve_btfids: Warn when having multiple IDs for single type | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 4 maintainers not CCed: kpsingh@kernel.org andrii@kernel.org sdf@google.com jackmanb@google.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 23 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
On Tue, Jan 5, 2021 at 7:39 AM Jiri Olsa <jolsa@kernel.org> wrote: > > The kernel image can contain multiple types (structs/unions) > with the same name. This causes distinct type hierarchies in > BTF data and makes resolve_btfids fail with error like: > > BTFIDS vmlinux > FAILED unresolved symbol udp6_sock > > as reported by Qais Yousef [1]. > > This change adds warning when multiple types of the same name > are detected: > > BTFIDS vmlinux > WARN: multiple IDs found for 'file' (526, 113351) > WARN: multiple IDs found for 'sk_buff' (2744, 113958) > > We keep the lower ID for the given type instance and let the > build continue. I think it would make sense to mention this decision in the warning. 'WARN: multiple IDs' is ambiguous and confusing when action is not specified.
On Tue, Jan 05, 2021 at 11:37:09AM -0800, Alexei Starovoitov wrote: > On Tue, Jan 5, 2021 at 7:39 AM Jiri Olsa <jolsa@kernel.org> wrote: > > > > The kernel image can contain multiple types (structs/unions) > > with the same name. This causes distinct type hierarchies in > > BTF data and makes resolve_btfids fail with error like: > > > > BTFIDS vmlinux > > FAILED unresolved symbol udp6_sock > > > > as reported by Qais Yousef [1]. > > > > This change adds warning when multiple types of the same name > > are detected: > > > > BTFIDS vmlinux > > WARN: multiple IDs found for 'file' (526, 113351) > > WARN: multiple IDs found for 'sk_buff' (2744, 113958) > > > > We keep the lower ID for the given type instance and let the > > build continue. > > I think it would make sense to mention this decision in the warning. > 'WARN: multiple IDs' is ambiguous and confusing when action is not specified. ok, how about: WARN: multiple IDs found for 'file': 526, 113351 - using 526 jirka
On Tue, Jan 5, 2021 at 11:50 AM Jiri Olsa <jolsa@redhat.com> wrote: > > On Tue, Jan 05, 2021 at 11:37:09AM -0800, Alexei Starovoitov wrote: > > On Tue, Jan 5, 2021 at 7:39 AM Jiri Olsa <jolsa@kernel.org> wrote: > > > > > > The kernel image can contain multiple types (structs/unions) > > > with the same name. This causes distinct type hierarchies in > > > BTF data and makes resolve_btfids fail with error like: > > > > > > BTFIDS vmlinux > > > FAILED unresolved symbol udp6_sock > > > > > > as reported by Qais Yousef [1]. > > > > > > This change adds warning when multiple types of the same name > > > are detected: > > > > > > BTFIDS vmlinux > > > WARN: multiple IDs found for 'file' (526, 113351) > > > WARN: multiple IDs found for 'sk_buff' (2744, 113958) > > > > > > We keep the lower ID for the given type instance and let the > > > build continue. > > > > I think it would make sense to mention this decision in the warning. > > 'WARN: multiple IDs' is ambiguous and confusing when action is not specified. > > ok, how about: > > WARN: multiple IDs found for 'file': 526, 113351 - using 526 yep. much better imo. Please add a comment to .c file with the suggestion that such types should be renamed to avoid ambiguity. Adding 'please rename' to WARN is probably overkill.
On Tue, Jan 5, 2021 at 7:41 AM Jiri Olsa <jolsa@kernel.org> wrote: > > The kernel image can contain multiple types (structs/unions) > with the same name. This causes distinct type hierarchies in > BTF data and makes resolve_btfids fail with error like: > > BTFIDS vmlinux > FAILED unresolved symbol udp6_sock > > as reported by Qais Yousef [1]. > > This change adds warning when multiple types of the same name > are detected: > > BTFIDS vmlinux > WARN: multiple IDs found for 'file' (526, 113351) > WARN: multiple IDs found for 'sk_buff' (2744, 113958) > > We keep the lower ID for the given type instance and let the > build continue. > > [1] https://lore.kernel.org/lkml/20201229151352.6hzmjvu3qh6p2qgg@e107158-lin/ > Reported-by: Qais Yousef <qais.yousef@arm.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- see comments below, but otherwise lgtm Acked-by: Andrii Nakryiko <andrii@kernel.org> > tools/bpf/resolve_btfids/main.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c > index e3ea569ee125..36a3b1024cdc 100644 > --- a/tools/bpf/resolve_btfids/main.c > +++ b/tools/bpf/resolve_btfids/main.c > @@ -139,6 +139,8 @@ int eprintf(int level, int var, const char *fmt, ...) > #define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__) > #define pr_err(fmt, ...) \ > eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) > +#define pr_info(fmt, ...) \ > + eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) how is it different from pr_err? Did you forget to update verboseness levels or it's intentional? > > static bool is_btf_id(const char *name) > { > @@ -526,8 +528,13 @@ static int symbols_resolve(struct object *obj) > > id = btf_id__find(root, str); > if (id) { > - id->id = type_id; > - (*nr)--; > + if (id->id) { > + pr_info("WARN: multiple IDs found for '%s' (%d, %d)\n", > + str, id->id, type_id); > + } else { > + id->id = type_id; > + (*nr)--; btw, there is a nasty shadowing of nr variable, which is used both for the for() loop condition (as int) and as `int *` inside the loop body. It's better to rename inner (or outer) nr, it's extremely confusing as is. > + } > } > } > > -- > 2.26.2 >
On Tue, Jan 05, 2021 at 01:15:39PM -0800, Andrii Nakryiko wrote: > On Tue, Jan 5, 2021 at 7:41 AM Jiri Olsa <jolsa@kernel.org> wrote: > > > > The kernel image can contain multiple types (structs/unions) > > with the same name. This causes distinct type hierarchies in > > BTF data and makes resolve_btfids fail with error like: > > > > BTFIDS vmlinux > > FAILED unresolved symbol udp6_sock > > > > as reported by Qais Yousef [1]. > > > > This change adds warning when multiple types of the same name > > are detected: > > > > BTFIDS vmlinux > > WARN: multiple IDs found for 'file' (526, 113351) > > WARN: multiple IDs found for 'sk_buff' (2744, 113958) > > > > We keep the lower ID for the given type instance and let the > > build continue. > > > > [1] https://lore.kernel.org/lkml/20201229151352.6hzmjvu3qh6p2qgg@e107158-lin/ > > Reported-by: Qais Yousef <qais.yousef@arm.com> > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > see comments below, but otherwise lgtm > > Acked-by: Andrii Nakryiko <andrii@kernel.org> > > > tools/bpf/resolve_btfids/main.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c > > index e3ea569ee125..36a3b1024cdc 100644 > > --- a/tools/bpf/resolve_btfids/main.c > > +++ b/tools/bpf/resolve_btfids/main.c > > @@ -139,6 +139,8 @@ int eprintf(int level, int var, const char *fmt, ...) > > #define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__) > > #define pr_err(fmt, ...) \ > > eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) > > +#define pr_info(fmt, ...) \ > > + eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) > > how is it different from pr_err? Did you forget to update verboseness > levels or it's intentional? intentional, I'm using pr_err to print in error paths, so I wanted to add new one for other 'info' messages without -v > > > > > static bool is_btf_id(const char *name) > > { > > @@ -526,8 +528,13 @@ static int symbols_resolve(struct object *obj) > > > > id = btf_id__find(root, str); > > if (id) { > > - id->id = type_id; > > - (*nr)--; > > + if (id->id) { > > + pr_info("WARN: multiple IDs found for '%s' (%d, %d)\n", > > + str, id->id, type_id); > > + } else { > > + id->id = type_id; > > + (*nr)--; > > btw, there is a nasty shadowing of nr variable, which is used both for > the for() loop condition (as int) and as `int *` inside the loop body. > It's better to rename inner (or outer) nr, it's extremely confusing as > is. nice, I'll change that thanks, jirka > > > + } > > } > > } > > > > -- > > 2.26.2 > > >
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c index e3ea569ee125..36a3b1024cdc 100644 --- a/tools/bpf/resolve_btfids/main.c +++ b/tools/bpf/resolve_btfids/main.c @@ -139,6 +139,8 @@ int eprintf(int level, int var, const char *fmt, ...) #define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__) #define pr_err(fmt, ...) \ eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) +#define pr_info(fmt, ...) \ + eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__) static bool is_btf_id(const char *name) { @@ -526,8 +528,13 @@ static int symbols_resolve(struct object *obj) id = btf_id__find(root, str); if (id) { - id->id = type_id; - (*nr)--; + if (id->id) { + pr_info("WARN: multiple IDs found for '%s' (%d, %d)\n", + str, id->id, type_id); + } else { + id->id = type_id; + (*nr)--; + } } }
The kernel image can contain multiple types (structs/unions) with the same name. This causes distinct type hierarchies in BTF data and makes resolve_btfids fail with error like: BTFIDS vmlinux FAILED unresolved symbol udp6_sock as reported by Qais Yousef [1]. This change adds warning when multiple types of the same name are detected: BTFIDS vmlinux WARN: multiple IDs found for 'file' (526, 113351) WARN: multiple IDs found for 'sk_buff' (2744, 113958) We keep the lower ID for the given type instance and let the build continue. [1] https://lore.kernel.org/lkml/20201229151352.6hzmjvu3qh6p2qgg@e107158-lin/ Reported-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/bpf/resolve_btfids/main.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)