| Message ID | 20240520124212.2351033-5-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kbuild: fix and clean-up after avoiding kallsyms weak reference | expand |
Hi Masahiro, kernel test robot noticed the following build errors: [auto build test ERROR on masahiroy-kbuild/for-next] [also build test ERROR on linus/master masahiroy-kbuild/fixes next-20240521] [cannot apply to v6.9] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/kbuild-avoid-unneeded-kallsyms-step-3/20240520-204508 base: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next patch link: https://lore.kernel.org/r/20240520124212.2351033-5-masahiroy%40kernel.org patch subject: [PATCH 4/4] kbuild: remove PROVIDE() for kallsyms symbols config: x86_64-rhel-8.3-bpf (https://download.01.org/0day-ci/archive/20240521/202405211448.fglQOQ9W-lkp@intel.com/config) compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240521/202405211448.fglQOQ9W-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202405211448.fglQOQ9W-lkp@intel.com/ All errors (new ones prefixed by >>): ld: vmlinux.o: in function `get_symbol_offset': >> kernel/kallsyms.c:125:(.text+0x2111af): undefined reference to `kallsyms_markers' >> ld: kernel/kallsyms.c:125:(.text+0x2111b5): undefined reference to `kallsyms_names' ld: kernel/kallsyms.c:146:(.text+0x2111eb): undefined reference to `kallsyms_names' ld: vmlinux.o: in function `get_symbol_pos': >> kernel/kallsyms.c:330:(.text+0x211218): undefined reference to `kallsyms_relative_base' >> ld: kernel/kallsyms.c:330:(.text+0x211226): undefined reference to `kallsyms_num_syms' ld: vmlinux.o: in function `kallsyms_sym_address': >> kernel/kallsyms.c:159:(.text+0x211245): undefined reference to `kallsyms_offsets' >> ld: kernel/kallsyms.c:159:(.text+0x211285): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:159:(.text+0x211296): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:159:(.text+0x2112b7): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:159:(.text+0x2112ec): undefined reference to `kallsyms_offsets' ld: vmlinux.o: in function `get_ksymbol_mod': >> kernel/kallsyms.c:623:(.text+0x211434): undefined reference to `kallsyms_num_syms' ld: vmlinux.o: in function `kallsyms_expand_symbol': >> kernel/kallsyms.c:50:(.text+0x21167d): undefined reference to `kallsyms_names' ld: kernel/kallsyms.c:51:(.text+0x211684): undefined reference to `kallsyms_names' >> ld: kernel/kallsyms.c:73:(.text+0x2116b6): undefined reference to `kallsyms_token_index' >> ld: kernel/kallsyms.c:73:(.text+0x2116bf): undefined reference to `kallsyms_token_table' ld: kernel/kallsyms.c:77:(.text+0x2116c6): undefined reference to `kallsyms_token_table' ld: vmlinux.o: in function `update_iter': kernel/kallsyms.c:740:(.text+0x211757): undefined reference to `kallsyms_num_syms' ld: vmlinux.o: in function `kallsyms_sym_address': kernel/kallsyms.c:159:(.text+0x211782): undefined reference to `kallsyms_offsets' >> ld: kernel/kallsyms.c:163:(.text+0x211790): undefined reference to `kallsyms_relative_base' ld: vmlinux.o: in function `kallsyms_get_symbol_type': kernel/kallsyms.c:108:(.text+0x21179e): undefined reference to `kallsyms_names' ld: kernel/kallsyms.c:108:(.text+0x2117aa): undefined reference to `kallsyms_token_index' ld: vmlinux.o: in function `get_ksymbol_core': >> kernel/kallsyms.c:693:(.text+0x2117b1): undefined reference to `kallsyms_token_table' ld: vmlinux.o: in function `kallsyms_lookup_names': kernel/kallsyms.c:218:(.text+0x211a48): undefined reference to `kallsyms_num_syms' ld: vmlinux.o: in function `get_symbol_seq': >> kernel/kallsyms.c:203:(.text+0x211a83): undefined reference to `kallsyms_seqs_of_names' >> ld: kernel/kallsyms.c:203:(.text+0x211a90): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x211a9c): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x211af2): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x211aff): undefined reference to `kallsyms_seqs_of_names' ld: vmlinux.o:kernel/kallsyms.c:203: more undefined references to `kallsyms_seqs_of_names' follow ld: vmlinux.o: in function `kallsyms_sym_address': kernel/kallsyms.c:159:(.text+0x211fb0): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:163:(.text+0x211fbe): undefined reference to `kallsyms_relative_base' ld: vmlinux.o: in function `get_symbol_seq': kernel/kallsyms.c:203:(.text+0x212049): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x212056): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x21205d): undefined reference to `kallsyms_seqs_of_names' ld: vmlinux.o: in function `kallsyms_sym_address': kernel/kallsyms.c:159:(.text+0x212071): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:163:(.text+0x21207f): undefined reference to `kallsyms_relative_base' ld: vmlinux.o: in function `kallsyms_on_each_symbol': kernel/kallsyms.c:293:(.text+0x2120e5): undefined reference to `kallsyms_num_syms' ld: vmlinux.o: in function `kallsyms_sym_address': kernel/kallsyms.c:159:(.text+0x21214b): undefined reference to `kallsyms_offsets' ld: kernel/kallsyms.c:163:(.text+0x212159): undefined reference to `kallsyms_relative_base' ld: kernel/kallsyms.c:163:(.text+0x212224): undefined reference to `kallsyms_relative_base' ld: vmlinux.o: in function `get_symbol_seq': kernel/kallsyms.c:203:(.text+0x212239): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x212240): undefined reference to `kallsyms_seqs_of_names' ld: kernel/kallsyms.c:203:(.text+0x212253): undefined reference to `kallsyms_seqs_of_names' ld: vmlinux.o: in function `kallsyms_sym_address': kernel/kallsyms.c:159:(.text+0x21225f): undefined reference to `kallsyms_offsets' ld: vmlinux.o: in function `crash_save_vmcoreinfo_init': >> kernel/vmcore_info.c:214:(.init.text+0x429d6): undefined reference to `kallsyms_names' >> ld: kernel/vmcore_info.c:215:(.init.text+0x429f0): undefined reference to `kallsyms_num_syms' >> ld: kernel/vmcore_info.c:216:(.init.text+0x42a0a): undefined reference to `kallsyms_token_table' >> ld: kernel/vmcore_info.c:217:(.init.text+0x42a24): undefined reference to `kallsyms_token_index' >> ld: kernel/vmcore_info.c:219:(.init.text+0x42a3e): undefined reference to `kallsyms_offsets' >> ld: kernel/vmcore_info.c:220:(.init.text+0x42a58): undefined reference to `kallsyms_relative_base' pahole: .tmp_vmlinux.btf: Invalid argument .btf.vmlinux.bin.o: file not recognized: file format not recognized vim +125 kernel/kallsyms.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 36 ad6ccfad6f759a Manish Katiyar 2009-05-12 37 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 38 * Expand a compressed symbol data into the resulting uncompressed string, e3f26752f0f8a6 Chen Gang 2013-04-15 39 * if uncompressed string is too long (>= maxlen), it will be truncated, ad6ccfad6f759a Manish Katiyar 2009-05-12 40 * given the offset to where the symbol is in the compressed stream. ad6ccfad6f759a Manish Katiyar 2009-05-12 41 */ e3f26752f0f8a6 Chen Gang 2013-04-15 42 static unsigned int kallsyms_expand_symbol(unsigned int off, e3f26752f0f8a6 Chen Gang 2013-04-15 43 char *result, size_t maxlen) ^1da177e4c3f41 Linus Torvalds 2005-04-16 44 { ^1da177e4c3f41 Linus Torvalds 2005-04-16 45 int len, skipped_first = 0; cde26a6e17ec36 Masahiro Yamada 2020-02-02 46 const char *tptr; cde26a6e17ec36 Masahiro Yamada 2020-02-02 47 const u8 *data; ^1da177e4c3f41 Linus Torvalds 2005-04-16 48 ad6ccfad6f759a Manish Katiyar 2009-05-12 49 /* Get the compressed symbol length from the first symbol byte. */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 @50 data = &kallsyms_names[off]; ^1da177e4c3f41 Linus Torvalds 2005-04-16 51 len = *data; ^1da177e4c3f41 Linus Torvalds 2005-04-16 52 data++; 73bbb94466fd3f Miguel Ojeda 2021-04-05 53 off++; 73bbb94466fd3f Miguel Ojeda 2021-04-05 54 73bbb94466fd3f Miguel Ojeda 2021-04-05 55 /* If MSB is 1, it is a "big" symbol, so needs an additional byte. */ 73bbb94466fd3f Miguel Ojeda 2021-04-05 56 if ((len & 0x80) != 0) { 73bbb94466fd3f Miguel Ojeda 2021-04-05 57 len = (len & 0x7F) | (*data << 7); 73bbb94466fd3f Miguel Ojeda 2021-04-05 58 data++; 73bbb94466fd3f Miguel Ojeda 2021-04-05 59 off++; 73bbb94466fd3f Miguel Ojeda 2021-04-05 60 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 61 ad6ccfad6f759a Manish Katiyar 2009-05-12 62 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 63 * Update the offset to return the offset for the next symbol on ad6ccfad6f759a Manish Katiyar 2009-05-12 64 * the compressed stream. ad6ccfad6f759a Manish Katiyar 2009-05-12 65 */ 73bbb94466fd3f Miguel Ojeda 2021-04-05 66 off += len; ^1da177e4c3f41 Linus Torvalds 2005-04-16 67 ad6ccfad6f759a Manish Katiyar 2009-05-12 68 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 69 * For every byte on the compressed symbol data, copy the table ad6ccfad6f759a Manish Katiyar 2009-05-12 70 * entry for that byte. ad6ccfad6f759a Manish Katiyar 2009-05-12 71 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 72 while (len) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 @73 tptr = &kallsyms_token_table[kallsyms_token_index[*data]]; ^1da177e4c3f41 Linus Torvalds 2005-04-16 74 data++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 75 len--; ^1da177e4c3f41 Linus Torvalds 2005-04-16 76 ^1da177e4c3f41 Linus Torvalds 2005-04-16 77 while (*tptr) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 78 if (skipped_first) { e3f26752f0f8a6 Chen Gang 2013-04-15 79 if (maxlen <= 1) e3f26752f0f8a6 Chen Gang 2013-04-15 80 goto tail; ^1da177e4c3f41 Linus Torvalds 2005-04-16 81 *result = *tptr; ^1da177e4c3f41 Linus Torvalds 2005-04-16 82 result++; e3f26752f0f8a6 Chen Gang 2013-04-15 83 maxlen--; ^1da177e4c3f41 Linus Torvalds 2005-04-16 84 } else ^1da177e4c3f41 Linus Torvalds 2005-04-16 85 skipped_first = 1; ^1da177e4c3f41 Linus Torvalds 2005-04-16 86 tptr++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 87 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 88 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 89 e3f26752f0f8a6 Chen Gang 2013-04-15 90 tail: e3f26752f0f8a6 Chen Gang 2013-04-15 91 if (maxlen) ^1da177e4c3f41 Linus Torvalds 2005-04-16 92 *result = '\0'; ^1da177e4c3f41 Linus Torvalds 2005-04-16 93 ad6ccfad6f759a Manish Katiyar 2009-05-12 94 /* Return to offset to the next symbol. */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 95 return off; ^1da177e4c3f41 Linus Torvalds 2005-04-16 96 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 97 ad6ccfad6f759a Manish Katiyar 2009-05-12 98 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 99 * Get symbol type information. This is encoded as a single char at the ad6ccfad6f759a Manish Katiyar 2009-05-12 100 * beginning of the symbol name. ad6ccfad6f759a Manish Katiyar 2009-05-12 101 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 102 static char kallsyms_get_symbol_type(unsigned int off) ^1da177e4c3f41 Linus Torvalds 2005-04-16 103 { ad6ccfad6f759a Manish Katiyar 2009-05-12 104 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 105 * Get just the first code, look it up in the token table, ad6ccfad6f759a Manish Katiyar 2009-05-12 106 * and return the first char from this token. ad6ccfad6f759a Manish Katiyar 2009-05-12 107 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 108 return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]]; ^1da177e4c3f41 Linus Torvalds 2005-04-16 109 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 110 ^1da177e4c3f41 Linus Torvalds 2005-04-16 111 ad6ccfad6f759a Manish Katiyar 2009-05-12 112 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 113 * Find the offset on the compressed stream given and index in the ad6ccfad6f759a Manish Katiyar 2009-05-12 114 * kallsyms array. ad6ccfad6f759a Manish Katiyar 2009-05-12 115 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 116 static unsigned int get_symbol_offset(unsigned long pos) ^1da177e4c3f41 Linus Torvalds 2005-04-16 117 { aad094701c6355 Jan Beulich 2006-12-08 118 const u8 *name; 73bbb94466fd3f Miguel Ojeda 2021-04-05 119 int i, len; ^1da177e4c3f41 Linus Torvalds 2005-04-16 120 ad6ccfad6f759a Manish Katiyar 2009-05-12 121 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 122 * Use the closest marker we have. We have markers every 256 positions, ad6ccfad6f759a Manish Katiyar 2009-05-12 123 * so that should be close enough. ad6ccfad6f759a Manish Katiyar 2009-05-12 124 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 @125 name = &kallsyms_names[kallsyms_markers[pos >> 8]]; ^1da177e4c3f41 Linus Torvalds 2005-04-16 126 ad6ccfad6f759a Manish Katiyar 2009-05-12 127 /* ad6ccfad6f759a Manish Katiyar 2009-05-12 128 * Sequentially scan all the symbols up to the point we're searching ad6ccfad6f759a Manish Katiyar 2009-05-12 129 * for. Every symbol is stored in a [<len>][<len> bytes of data] format, ad6ccfad6f759a Manish Katiyar 2009-05-12 130 * so we just need to add the len to the current pointer for every ad6ccfad6f759a Manish Katiyar 2009-05-12 131 * symbol we wish to skip. ad6ccfad6f759a Manish Katiyar 2009-05-12 132 */ 73bbb94466fd3f Miguel Ojeda 2021-04-05 133 for (i = 0; i < (pos & 0xFF); i++) { 73bbb94466fd3f Miguel Ojeda 2021-04-05 134 len = *name; 73bbb94466fd3f Miguel Ojeda 2021-04-05 135 73bbb94466fd3f Miguel Ojeda 2021-04-05 136 /* 73bbb94466fd3f Miguel Ojeda 2021-04-05 137 * If MSB is 1, it is a "big" symbol, so we need to look into 73bbb94466fd3f Miguel Ojeda 2021-04-05 138 * the next byte (and skip it, too). 73bbb94466fd3f Miguel Ojeda 2021-04-05 139 */ 73bbb94466fd3f Miguel Ojeda 2021-04-05 140 if ((len & 0x80) != 0) 73bbb94466fd3f Miguel Ojeda 2021-04-05 141 len = ((len & 0x7F) | (name[1] << 7)) + 1; 73bbb94466fd3f Miguel Ojeda 2021-04-05 142 73bbb94466fd3f Miguel Ojeda 2021-04-05 143 name = name + len + 1; 73bbb94466fd3f Miguel Ojeda 2021-04-05 144 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 145 ^1da177e4c3f41 Linus Torvalds 2005-04-16 146 return name - kallsyms_names; ^1da177e4c3f41 Linus Torvalds 2005-04-16 147 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 148 30f3bb09778de6 Zhen Lei 2022-11-15 149 unsigned long kallsyms_sym_address(int idx) 2213e9a66bb87d Ard Biesheuvel 2016-03-15 150 { 2213e9a66bb87d Ard Biesheuvel 2016-03-15 151 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) 2213e9a66bb87d Ard Biesheuvel 2016-03-15 152 return kallsyms_addresses[idx]; 2213e9a66bb87d Ard Biesheuvel 2016-03-15 153 2213e9a66bb87d Ard Biesheuvel 2016-03-15 154 /* values are unsigned offsets if --absolute-percpu is not in effect */ 2213e9a66bb87d Ard Biesheuvel 2016-03-15 155 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU)) 2213e9a66bb87d Ard Biesheuvel 2016-03-15 156 return kallsyms_relative_base + (u32)kallsyms_offsets[idx]; 2213e9a66bb87d Ard Biesheuvel 2016-03-15 157 2213e9a66bb87d Ard Biesheuvel 2016-03-15 158 /* ...otherwise, positive offsets are absolute values */ 2213e9a66bb87d Ard Biesheuvel 2016-03-15 @159 if (kallsyms_offsets[idx] >= 0) 2213e9a66bb87d Ard Biesheuvel 2016-03-15 160 return kallsyms_offsets[idx]; 2213e9a66bb87d Ard Biesheuvel 2016-03-15 161 2213e9a66bb87d Ard Biesheuvel 2016-03-15 162 /* ...and negative offsets are relative to kallsyms_relative_base - 1 */ 2213e9a66bb87d Ard Biesheuvel 2016-03-15 @163 return kallsyms_relative_base - 1 - kallsyms_offsets[idx]; 2213e9a66bb87d Ard Biesheuvel 2016-03-15 164 } 2213e9a66bb87d Ard Biesheuvel 2016-03-15 165 76903a9648744c Yonghong Song 2023-08-25 166 static void cleanup_symbol_name(char *s) 8b8e6b5d3b013b Sami Tolvanen 2021-04-08 167 { 8b8e6b5d3b013b Sami Tolvanen 2021-04-08 168 char *res; 8b8e6b5d3b013b Sami Tolvanen 2021-04-08 169 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 170 if (!IS_ENABLED(CONFIG_LTO_CLANG)) 76903a9648744c Yonghong Song 2023-08-25 171 return; 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 172 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 173 /* 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 174 * LLVM appends various suffixes for local functions and variables that 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 175 * must be promoted to global scope as part of LTO. This can break 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 176 * hooking of static functions with kprobes. '.' is not a valid 8cc32a9bbf2934 Yonghong Song 2023-06-28 177 * character in an identifier in C. Suffixes only in LLVM LTO observed: 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 178 * - foo.llvm.[0-9a-f]+ 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 179 */ 8cc32a9bbf2934 Yonghong Song 2023-06-28 180 res = strstr(s, ".llvm."); 76903a9648744c Yonghong Song 2023-08-25 181 if (res) 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 182 *res = '\0'; 6eb4bd92c1cedc Nick Desaulniers 2021-10-04 183 76903a9648744c Yonghong Song 2023-08-25 184 return; 8b8e6b5d3b013b Sami Tolvanen 2021-04-08 185 } 8b8e6b5d3b013b Sami Tolvanen 2021-04-08 186 60443c88f3a89f Zhen Lei 2022-11-02 187 static int compare_symbol_name(const char *name, char *namebuf) 60443c88f3a89f Zhen Lei 2022-11-02 188 { 33f0467fe06934 Yonghong Song 2023-08-24 189 /* The kallsyms_seqs_of_names is sorted based on names after 33f0467fe06934 Yonghong Song 2023-08-24 190 * cleanup_symbol_name() (see scripts/kallsyms.c) if clang lto is enabled. 33f0467fe06934 Yonghong Song 2023-08-24 191 * To ensure correct bisection in kallsyms_lookup_names(), do 33f0467fe06934 Yonghong Song 2023-08-24 192 * cleanup_symbol_name(namebuf) before comparing name and namebuf. 33f0467fe06934 Yonghong Song 2023-08-24 193 */ 33f0467fe06934 Yonghong Song 2023-08-24 194 cleanup_symbol_name(namebuf); 33f0467fe06934 Yonghong Song 2023-08-24 195 return strcmp(name, namebuf); 60443c88f3a89f Zhen Lei 2022-11-02 196 } 60443c88f3a89f Zhen Lei 2022-11-02 197 19bd8981dc2ee3 Zhen Lei 2022-11-02 198 static unsigned int get_symbol_seq(int index) 19bd8981dc2ee3 Zhen Lei 2022-11-02 199 { 19bd8981dc2ee3 Zhen Lei 2022-11-02 200 unsigned int i, seq = 0; 19bd8981dc2ee3 Zhen Lei 2022-11-02 201 19bd8981dc2ee3 Zhen Lei 2022-11-02 202 for (i = 0; i < 3; i++) 19bd8981dc2ee3 Zhen Lei 2022-11-02 @203 seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i]; 19bd8981dc2ee3 Zhen Lei 2022-11-02 204 19bd8981dc2ee3 Zhen Lei 2022-11-02 205 return seq; 19bd8981dc2ee3 Zhen Lei 2022-11-02 206 } 19bd8981dc2ee3 Zhen Lei 2022-11-02 207
On Tue, May 21, 2024 at 4:13 PM kernel test robot <lkp@intel.com> wrote: > > Hi Masahiro, > > kernel test robot noticed the following build errors: > > [auto build test ERROR on masahiroy-kbuild/for-next] > [also build test ERROR on linus/master masahiroy-kbuild/fixes next-20240521] > [cannot apply to v6.9] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/kbuild-avoid-unneeded-kallsyms-step-3/20240520-204508 > base: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next > patch link: https://lore.kernel.org/r/20240520124212.2351033-5-masahiroy%40kernel.org > patch subject: [PATCH 4/4] kbuild: remove PROVIDE() for kallsyms symbols > config: x86_64-rhel-8.3-bpf (https://download.01.org/0day-ci/archive/20240521/202405211448.fglQOQ9W-lkp@intel.com/config) > compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0 > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240521/202405211448.fglQOQ9W-lkp@intel.com/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@intel.com> > | Closes: https://lore.kernel.org/oe-kbuild-all/202405211448.fglQOQ9W-lkp@intel.com/ > > All errors (new ones prefixed by >>): Thanks, I will move kallsyms step 0 before btf creation.
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 870753fbb123..9752eb420ffa 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -448,30 +448,11 @@ #endif #endif -/* - * Some symbol definitions will not exist yet during the first pass of the - * link, but are guaranteed to exist in the final link. Provide preliminary - * definitions that will be superseded in the final link to avoid having to - * rely on weak external linkage, which requires a GOT when used in position - * independent code. - */ -#define PRELIMINARY_SYMBOL_DEFINITIONS \ - PROVIDE(kallsyms_addresses = .); \ - PROVIDE(kallsyms_offsets = .); \ - PROVIDE(kallsyms_names = .); \ - PROVIDE(kallsyms_num_syms = .); \ - PROVIDE(kallsyms_relative_base = .); \ - PROVIDE(kallsyms_token_table = .); \ - PROVIDE(kallsyms_token_index = .); \ - PROVIDE(kallsyms_markers = .); \ - PROVIDE(kallsyms_seqs_of_names = .); - /* * Read only Data */ #define RO_DATA(align) \ . = ALIGN((align)); \ - PRELIMINARY_SYMBOL_DEFINITIONS \ .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \ __start_rodata = .; \ *(.rodata) *(.rodata.*) \ diff --git a/kernel/kallsyms_internal.h b/kernel/kallsyms_internal.h index 85480274fc8f..925f2ab22639 100644 --- a/kernel/kallsyms_internal.h +++ b/kernel/kallsyms_internal.h @@ -4,11 +4,6 @@ #include <linux/types.h> -/* - * These will be re-linked against their real values during the second link - * stage. Preliminary values must be provided in the linker script using the - * PROVIDE() directive so that the first link stage can complete successfully. - */ extern const unsigned long kallsyms_addresses[]; extern const int kallsyms_offsets[]; extern const u8 kallsyms_names[]; diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 653b92f6d4c8..6b90f52fd707 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -246,12 +246,6 @@ static void shrink_table(void) } } table_cnt = pos; - - /* When valid symbol is not registered, exit to error */ - if (!table_cnt) { - fprintf(stderr, "No valid symbol.\n"); - exit(1); - } } static void read_map(const char *in) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 7aca51b24e9f..242a92e24f20 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -165,27 +165,25 @@ kallsyms() kallsymopt="${kallsymopt} --lto-clang" fi - info KSYMS ${2} - scripts/kallsyms ${kallsymopt} ${1} > ${2} + info KSYMS "${2}.S" + scripts/kallsyms ${kallsymopt} "${1}" > "${2}.S" + + info AS "${2}.o" + ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \ + ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ + -c -o "${2}.o" "${2}.S" + kallsymso=${2}.o } # Perform one step in kallsyms generation, including temporary linking of # vmlinux. kallsyms_step() { - kallsymso_prev=${kallsymso} kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1} - kallsymso=${kallsyms_vmlinux}.o - kallsyms_S=${kallsyms_vmlinux}.S - vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o} - mksysmap ${kallsyms_vmlinux} ${kallsyms_vmlinux}.syms - kallsyms ${kallsyms_vmlinux}.syms ${kallsyms_S} - - info AS ${kallsymso} - ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \ - ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ - -c -o ${kallsymso} ${kallsyms_S} + vmlinux_link "${kallsyms_vmlinux}" "${kallsymso}" "${btf_vmlinux_bin_o}" + mksysmap "${kallsyms_vmlinux}" "${kallsyms_vmlinux}.syms" + kallsyms "${kallsyms_vmlinux}.syms" "${kallsyms_vmlinux}" } # Create map file with all symbols from ${1} @@ -235,15 +233,15 @@ if is_enabled CONFIG_DEBUG_INFO_BTF; then fi kallsymso="" -kallsymso_prev="" -kallsyms_vmlinux="" if is_enabled CONFIG_KALLSYMS; then # kallsyms support # Generate section listing all symbols and add it into vmlinux - # It's a three step process: + # It's a four step process: + # 0) Generate a dummy __kallsyms, which has zero symbols, but a valid + # format. # 1) Link .tmp_vmlinux.kallsyms1 so it has all symbols and sections, - # but __kallsyms is empty. + # with a dummy __kallsyms. # Running kallsyms on that gives us .tmp_kallsyms1.o with # the right size # 2) Link .tmp_vmlinux.kallsyms2 so it now has a __kallsyms section of @@ -262,13 +260,18 @@ if is_enabled CONFIG_KALLSYMS; then # a) Verify that the System.map from vmlinux matches the map from # ${kallsymso}. - kallsyms_step 1 - kallsyms_step 2 + # step 0 + kallsyms /dev/null .tmp_vmlinux.kallsyms0 - # step 3 - size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev}) + # step 1 + kallsyms_step 1 + size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso}) + + # step 2 + kallsyms_step 2 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso}) + # step 3 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then kallsyms_step 3 fi
This reimplements commit 951bcae6c5a0 ("kallsyms: Avoid weak references for kallsyms symbols"). I am not a big fan of PROVIDE() because it always satisfies the linker even in situations that should result in a link error. In other words, it can potentially shift a compile-time error into a run-time error. Duplicating kallsyms_* in vmlinux.lds.h also reduces maintainability. I shuffled scripts/link-vmlinux.sh to prepend one more kallsyms step. The following logs illustrates how it works. [Before] LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.o LD .tmp_vmlinux.kallsyms2 NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.o LD vmlinux [After] KSYMS .tmp_vmlinux.kallsyms0.S # added AS .tmp_vmlinux.kallsyms0.o # added LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.o LD .tmp_vmlinux.kallsyms2 NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.o LD vmlinux Step 0 takes /dev/null as input, and generates .tmp_vmlinux.kallsyms0.o, which has a valid kallsyms format with zero symbols, and can be linked to vmlinux. Since it is really small, the added compile-time cost is negligible. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- include/asm-generic/vmlinux.lds.h | 19 ------------- kernel/kallsyms_internal.h | 5 ---- scripts/kallsyms.c | 6 ----- scripts/link-vmlinux.sh | 45 ++++++++++++++++--------------- 4 files changed, 24 insertions(+), 51 deletions(-)