On Sun, Jul 4, 2021 at 1:28 PM <ojeda@xxxxxxxxxx> wrote: > > From: Miguel Ojeda <ojeda@xxxxxxxxxx> > > Rust symbols can become quite long due to namespacing introduced > by modules, types, traits, generics, etc. For instance, for: > > pub mod my_module { > pub struct MyType; > pub struct MyGenericType<T>(T); > > pub trait MyTrait { > fn my_method() -> u32; > } > > impl MyTrait for MyGenericType<MyType> { > fn my_method() -> u32 { > 42 > } > } > } > > generates a symbol of length 96 when using the upcoming v0 mangling scheme: > > _RNvXNtCshGpAVYOtgW1_7example9my_moduleINtB2_13MyGenericTypeNtB2_6MyTypeENtB2_7MyTrait9my_method For C++ demangling, we have c++filt. A quick search turned up: https://github.com/luser/rustfilt but if the v0 mangling scheme is upcoming, I doubt a repo that hasn't been updated supports an upcoming scheme. Is there a more official equivalent? Do we demangle rust symbols when printing a trace from a warn/panic? That would be nice. > > At the moment, Rust symbols may reach up to 300 in length. > Setting 512 as the maximum seems like a reasonable choice to > keep some headroom. > > Co-developed-by: Alex Gaynor <alex.gaynor@xxxxxxxxx> > Signed-off-by: Alex Gaynor <alex.gaynor@xxxxxxxxx> > Co-developed-by: Geoffrey Thomas <geofft@xxxxxxxxxxxxx> > Signed-off-by: Geoffrey Thomas <geofft@xxxxxxxxxxxxx> > Co-developed-by: Finn Behrens <me@xxxxxxxxx> > Signed-off-by: Finn Behrens <me@xxxxxxxxx> > Co-developed-by: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> > Signed-off-by: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> > Co-developed-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx> > Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx> > Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> > --- > include/linux/kallsyms.h | 2 +- > kernel/livepatch/core.c | 4 ++-- > scripts/kallsyms.c | 2 +- > tools/include/linux/kallsyms.h | 2 +- > tools/include/linux/lockdep.h | 2 +- > tools/lib/perf/include/perf/event.h | 2 +- > tools/lib/symbol/kallsyms.h | 2 +- > 7 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h > index 465060acc98..5cdc6903abc 100644 > --- a/include/linux/kallsyms.h > +++ b/include/linux/kallsyms.h > @@ -14,7 +14,7 @@ > > #include <asm/sections.h> > > -#define KSYM_NAME_LEN 128 > +#define KSYM_NAME_LEN 512 > #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \ > 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1) > > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > index 335d988bd81..73874e5edfd 100644 > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -213,7 +213,7 @@ static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, > * we use the smallest/strictest upper bound possible (56, based on > * the current definition of MODULE_NAME_LEN) to prevent overflows. > */ > - BUILD_BUG_ON(MODULE_NAME_LEN < 56 || KSYM_NAME_LEN != 128); > + BUILD_BUG_ON(MODULE_NAME_LEN < 56 || KSYM_NAME_LEN != 512); > > relas = (Elf_Rela *) relasec->sh_addr; > /* For each rela in this klp relocation section */ > @@ -227,7 +227,7 @@ static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, > > /* Format: .klp.sym.sym_objname.sym_name,sympos */ > cnt = sscanf(strtab + sym->st_name, > - ".klp.sym.%55[^.].%127[^,],%lu", > + ".klp.sym.%55[^.].%511[^,],%lu", > sym_objname, sym_name, &sympos); > if (cnt != 3) { > pr_err("symbol %s has an incorrectly formatted name\n", > diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c > index bcdabee13aa..9bab5f55ade 100644 > --- a/scripts/kallsyms.c > +++ b/scripts/kallsyms.c > @@ -27,7 +27,7 @@ > > #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0])) > > -#define KSYM_NAME_LEN 128 > +#define KSYM_NAME_LEN 512 > > struct sym_entry { > unsigned long long addr; > diff --git a/tools/include/linux/kallsyms.h b/tools/include/linux/kallsyms.h > index efb6c3f5f2a..5a37ccbec54 100644 > --- a/tools/include/linux/kallsyms.h > +++ b/tools/include/linux/kallsyms.h > @@ -6,7 +6,7 @@ > #include <stdio.h> > #include <unistd.h> > > -#define KSYM_NAME_LEN 128 > +#define KSYM_NAME_LEN 512 > > struct module; > > diff --git a/tools/include/linux/lockdep.h b/tools/include/linux/lockdep.h > index e56997288f2..d9c163f3ab2 100644 > --- a/tools/include/linux/lockdep.h > +++ b/tools/include/linux/lockdep.h > @@ -47,7 +47,7 @@ static inline int debug_locks_off(void) > > #define task_pid_nr(tsk) ((tsk)->pid) > > -#define KSYM_NAME_LEN 128 > +#define KSYM_NAME_LEN 512 > #define printk(...) dprintf(STDOUT_FILENO, __VA_ARGS__) > #define pr_err(format, ...) fprintf (stderr, format, ## __VA_ARGS__) > #define pr_warn pr_err > diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h > index 4d0c02ba3f7..095d60144a7 100644 > --- a/tools/lib/perf/include/perf/event.h > +++ b/tools/lib/perf/include/perf/event.h > @@ -95,7 +95,7 @@ struct perf_record_throttle { > }; > > #ifndef KSYM_NAME_LEN > -#define KSYM_NAME_LEN 256 > +#define KSYM_NAME_LEN 512 > #endif > > struct perf_record_ksymbol { > diff --git a/tools/lib/symbol/kallsyms.h b/tools/lib/symbol/kallsyms.h > index 72ab9870454..542f9b059c3 100644 > --- a/tools/lib/symbol/kallsyms.h > +++ b/tools/lib/symbol/kallsyms.h > @@ -7,7 +7,7 @@ > #include <linux/types.h> > > #ifndef KSYM_NAME_LEN > -#define KSYM_NAME_LEN 256 > +#define KSYM_NAME_LEN 512 > #endif > > static inline u8 kallsyms2elf_binding(char type) > -- > 2.32.0 > -- Thanks, ~Nick Desaulniers