From 64e166099b69bfc09f667253358a15160b86ea43 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Wed, 21 Feb 2024 21:26:53 +0100 Subject: [PATCH] kallsyms: get rid of code for absolute kallsyms Commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture") removed the last use of the absolute kallsyms. Signed-off-by: Jann Horn Acked-by: Arnd Bergmann Link: https://lore.kernel.org/all/20240221202655.2423854-1-jannh@google.com/ [masahiroy@kernel.org: rebase the code and reword the commit description] Signed-off-by: Masahiro Yamada --- init/Kconfig | 18 ------- kernel/kallsyms.c | 5 +- kernel/kallsyms_internal.h | 1 - kernel/vmcore_info.c | 4 -- scripts/kallsyms.c | 76 ++++++++++++----------------- scripts/link-vmlinux.sh | 4 -- tools/perf/tests/vmlinux-kallsyms.c | 1 - 7 files changed, 32 insertions(+), 77 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index febdea2afc3b..8e21ce38dee6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1789,24 +1789,6 @@ config KALLSYMS_ABSOLUTE_PERCPU depends on KALLSYMS default X86_64 && SMP -config KALLSYMS_BASE_RELATIVE - bool - depends on KALLSYMS - default y - help - Instead of emitting them as absolute values in the native word size, - emit the symbol references in the kallsyms table as 32-bit entries, - each containing a relative value in the range [base, base + U32_MAX] - or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either - an absolute value in the range [0, S32_MAX] or a relative value in the - range [base, base + S32_MAX], where base is the lowest relative symbol - address encountered in the image. - - On 64-bit builds, this reduces the size of the address table by 50%, - but more importantly, it results in entries whose values are build - time constants, and no relocation pass is required at runtime to fix - up the entries based on the runtime load address of the kernel. - # end of the "standard kernel features (expert users)" menu config ARCH_HAS_MEMBARRIER_CALLBACKS diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 98b9622d372e..fb2c77368d18 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -148,9 +148,6 @@ static unsigned int get_symbol_offset(unsigned long pos) unsigned long kallsyms_sym_address(int idx) { - if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) - return kallsyms_addresses[idx]; - /* values are unsigned offsets if --absolute-percpu is not in effect */ if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU)) return kallsyms_relative_base + (u32)kallsyms_offsets[idx]; @@ -325,7 +322,7 @@ static unsigned long get_symbol_pos(unsigned long addr, unsigned long symbol_start = 0, symbol_end = 0; unsigned long i, low, high, mid; - /* Do a binary search on the sorted kallsyms_addresses array. */ + /* Do a binary search on the sorted kallsyms_offsets array. */ low = 0; high = kallsyms_num_syms; diff --git a/kernel/kallsyms_internal.h b/kernel/kallsyms_internal.h index 925f2ab22639..9633782f8250 100644 --- a/kernel/kallsyms_internal.h +++ b/kernel/kallsyms_internal.h @@ -4,7 +4,6 @@ #include -extern const unsigned long kallsyms_addresses[]; extern const int kallsyms_offsets[]; extern const u8 kallsyms_names[]; diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c index 1d5eadd9dd61..8b4f8cc2e0ec 100644 --- a/kernel/vmcore_info.c +++ b/kernel/vmcore_info.c @@ -216,12 +216,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(kallsyms_num_syms); VMCOREINFO_SYMBOL(kallsyms_token_table); VMCOREINFO_SYMBOL(kallsyms_token_index); -#ifdef CONFIG_KALLSYMS_BASE_RELATIVE VMCOREINFO_SYMBOL(kallsyms_offsets); VMCOREINFO_SYMBOL(kallsyms_relative_base); -#else - VMCOREINFO_SYMBOL(kallsyms_addresses); -#endif /* CONFIG_KALLSYMS_BASE_RELATIVE */ #endif /* CONFIG_KALLSYMS */ arch_crash_save_vmcoreinfo(); diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index fa53b5eef553..55a423519f2e 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -6,7 +6,7 @@ * of the GNU General Public License, incorporated herein by reference. * * Usage: kallsyms [--all-symbols] [--absolute-percpu] - * [--base-relative] [--lto-clang] in.map > out.S + * [--lto-clang] in.map > out.S * * Table compression uses all the unused char codes on the symbols and * maps these to the most used substrings (tokens). For instance, it might @@ -63,7 +63,6 @@ static struct sym_entry **table; static unsigned int table_size, table_cnt; static int all_symbols; static int absolute_percpu; -static int base_relative; static int lto_clang; static int token_profit[0x10000]; @@ -76,7 +75,7 @@ static unsigned char best_table_len[256]; static void usage(void) { fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] " - "[--base-relative] [--lto-clang] in.map > out.S\n"); + "[--lto-clang] in.map > out.S\n"); exit(1); } @@ -491,54 +490,43 @@ static void write_src(void) printf("\t.short\t%d\n", best_idx[i]); printf("\n"); - if (!base_relative) - output_label("kallsyms_addresses"); - else - output_label("kallsyms_offsets"); + output_label("kallsyms_offsets"); for (i = 0; i < table_cnt; i++) { - if (base_relative) { - /* - * Use the offset relative to the lowest value - * encountered of all relative symbols, and emit - * non-relocatable fixed offsets that will be fixed - * up at runtime. - */ + /* + * Use the offset relative to the lowest value + * encountered of all relative symbols, and emit + * non-relocatable fixed offsets that will be fixed + * up at runtime. + */ - long long offset; - int overflow; + long long offset; + int overflow; - if (!absolute_percpu) { - offset = table[i]->addr - relative_base; - overflow = (offset < 0 || offset > UINT_MAX); - } else if (symbol_absolute(table[i])) { - offset = table[i]->addr; - overflow = (offset < 0 || offset > INT_MAX); - } else { - offset = relative_base - table[i]->addr - 1; - overflow = (offset < INT_MIN || offset >= 0); - } - if (overflow) { - fprintf(stderr, "kallsyms failure: " - "%s symbol value %#llx out of range in relative mode\n", - symbol_absolute(table[i]) ? "absolute" : "relative", - table[i]->addr); - exit(EXIT_FAILURE); - } - printf("\t.long\t%#x /* %s */\n", (int)offset, table[i]->sym); - } else if (!symbol_absolute(table[i])) { - output_address(table[i]->addr); + if (!absolute_percpu) { + offset = table[i]->addr - relative_base; + overflow = (offset < 0 || offset > UINT_MAX); + } else if (symbol_absolute(table[i])) { + offset = table[i]->addr; + overflow = (offset < 0 || offset > INT_MAX); } else { - printf("\tPTR\t%#llx\n", table[i]->addr); + offset = relative_base - table[i]->addr - 1; + overflow = (offset < INT_MIN || offset >= 0); } + if (overflow) { + fprintf(stderr, "kallsyms failure: " + "%s symbol value %#llx out of range in relative mode\n", + symbol_absolute(table[i]) ? "absolute" : "relative", + table[i]->addr); + exit(EXIT_FAILURE); + } + printf("\t.long\t%#x /* %s */\n", (int)offset, table[i]->sym); } printf("\n"); - if (base_relative) { - output_label("kallsyms_relative_base"); - output_address(relative_base); - printf("\n"); - } + output_label("kallsyms_relative_base"); + output_address(relative_base); + printf("\n"); if (lto_clang) for (i = 0; i < table_cnt; i++) @@ -820,7 +808,6 @@ int main(int argc, char **argv) static const struct option long_options[] = { {"all-symbols", no_argument, &all_symbols, 1}, {"absolute-percpu", no_argument, &absolute_percpu, 1}, - {"base-relative", no_argument, &base_relative, 1}, {"lto-clang", no_argument, <o_clang, 1}, {}, }; @@ -841,8 +828,7 @@ int main(int argc, char **argv) if (absolute_percpu) make_percpus_absolute(); sort_symbols(); - if (base_relative) - record_relative_base(); + record_relative_base(); optimize_token_table(); write_src(); diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index c64158a04f82..f7b2503cdba9 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -156,10 +156,6 @@ kallsyms() kallsymopt="${kallsymopt} --absolute-percpu" fi - if is_enabled CONFIG_KALLSYMS_BASE_RELATIVE; then - kallsymopt="${kallsymopt} --base-relative" - fi - if is_enabled CONFIG_LTO_CLANG; then kallsymopt="${kallsymopt} --lto-clang" fi diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c index e30fd55f8e51..cd3b480d20bd 100644 --- a/tools/perf/tests/vmlinux-kallsyms.c +++ b/tools/perf/tests/vmlinux-kallsyms.c @@ -26,7 +26,6 @@ static bool is_ignored_symbol(const char *name, char type) * when --all-symbols is specified so exclude them to get a * stable symbol list. */ - "kallsyms_addresses", "kallsyms_offsets", "kallsyms_relative_base", "kallsyms_num_syms",