[PATCH v9 05/27] kallsyms: increase maximum kernel symbol length to 512
From: Miguel Ojeda <ojeda@kernel.org>
Date: 2022-08-05 15:43:50
Also in:
linux-fsdevel, linux-patches, linux-perf-users, lkml, rust-for-linux
Subsystem:
live patching, performance events subsystem, the rest · Maintainers:
Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Rust symbols can become quite long due to namespacing introduced
by modules, types, traits, generics, etc. For instance,
the following code:
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
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.
Reviewed-by: Kees Cook <redacted>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Co-developed-by: Alex Gaynor <redacted>
Signed-off-by: Alex Gaynor <redacted>
Co-developed-by: Wedson Almeida Filho <redacted>
Signed-off-by: Wedson Almeida Filho <redacted>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boqun Feng <redacted>
Signed-off-by: Boqun Feng <redacted>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
include/linux/kallsyms.h | 2 +-
kernel/livepatch/core.c | 4 ++--
scripts/kallsyms.c | 4 ++--
tools/include/linux/kallsyms.h | 2 +-
tools/lib/perf/include/perf/event.h | 2 +-
tools/lib/symbol/kallsyms.h | 2 +-
6 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index ad39636e0c3f..649faac31ddb 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h@@ -15,7 +15,7 @@ #include <asm/sections.h> -#define KSYM_NAME_LEN 128 +#define KSYM_NAME_LEN 512 #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s %s]") + \ (KSYM_NAME_LEN - 1) + \ 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + \
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index bc475e62279d..ec06ce59d728 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c@@ -213,7 +213,7 @@ static int klp_resolve_symbols(Elf_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(Elf_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 9da3b7767e9d..3b64dda7e4cc 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c@@ -30,10 +30,10 @@ #define _stringify_1(x) #x #define _stringify(x) _stringify_1(x) -#define KSYM_NAME_LEN 128 +#define KSYM_NAME_LEN 512 /* A substantially bigger size than the current maximum. */ -#define KSYM_NAME_LEN_BUFFER 512 +#define KSYM_NAME_LEN_BUFFER 2048 _Static_assert( KSYM_NAME_LEN_BUFFER == KSYM_NAME_LEN * 4, "Please keep KSYM_NAME_LEN_BUFFER in sync with KSYM_NAME_LEN"
diff --git a/tools/include/linux/kallsyms.h b/tools/include/linux/kallsyms.h
index efb6c3f5f2a9..5a37ccbec54f 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/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index e7758707cadd..116a80c31675 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 72ab9870454b..542f9b059c3b 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)
--
2.37.1