From fd593d12770d4a0d1ff095d44b96436c18479ee8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 7 Dec 2006 02:14:04 +0100 Subject: [PATCH] [PATCH] relocatable kernel: Kallsyms generate relocatable symbols Print the addresses of non-absolute symbols relative to _text so that ld will generate relocations. Allowing a relocatable kernel to relocate them. We can't actually use the symbol names because kallsyms includes static symbols that are not exported from their object files. Add the _text symbol definitions to the architectures which don't define it otherwise linker will fail. Signed-off-by: Eric W. Biederman Signed-off-by: Vivek Goyal Signed-off-by: Andi Kleen --- arch/h8300/kernel/vmlinux.lds.S | 1 + arch/m68knommu/kernel/vmlinux.lds.S | 1 + arch/powerpc/kernel/vmlinux.lds.S | 1 + arch/ppc/kernel/vmlinux.lds.S | 1 + arch/sparc/kernel/vmlinux.lds.S | 1 + arch/sparc64/kernel/vmlinux.lds.S | 1 + arch/v850/kernel/vmlinux.lds.S | 1 + scripts/kallsyms.c | 20 +++++++++++++++++--- 8 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S index 756325dd480e..f05288be8878 100644 --- a/arch/h8300/kernel/vmlinux.lds.S +++ b/arch/h8300/kernel/vmlinux.lds.S @@ -70,6 +70,7 @@ SECTIONS #endif .text : { + _text = .; #if defined(CONFIG_ROMKERNEL) *(.int_redirect) #endif diff --git a/arch/m68knommu/kernel/vmlinux.lds.S b/arch/m68knommu/kernel/vmlinux.lds.S index 58afa8be604e..2b2a10da64a4 100644 --- a/arch/m68knommu/kernel/vmlinux.lds.S +++ b/arch/m68knommu/kernel/vmlinux.lds.S @@ -60,6 +60,7 @@ SECTIONS { #endif .text : { + _text = .; _stext = . ; *(.text) SCHED_TEXT diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index e8342d867536..04b98671a060 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -33,6 +33,7 @@ SECTIONS /* Text and gots */ .text : { + _text = .; *(.text .text.*) SCHED_TEXT LOCK_TEXT diff --git a/arch/ppc/kernel/vmlinux.lds.S b/arch/ppc/kernel/vmlinux.lds.S index 16e8661e1fec..61921268a0d0 100644 --- a/arch/ppc/kernel/vmlinux.lds.S +++ b/arch/ppc/kernel/vmlinux.lds.S @@ -31,6 +31,7 @@ SECTIONS .plt : { *(.plt) } .text : { + _text = .; *(.text) SCHED_TEXT LOCK_TEXT diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S index 5cc5ff7f8824..b73e6b9067ed 100644 --- a/arch/sparc/kernel/vmlinux.lds.S +++ b/arch/sparc/kernel/vmlinux.lds.S @@ -11,6 +11,7 @@ SECTIONS . = 0x10000 + SIZEOF_HEADERS; .text 0xf0004000 : { + _text = .; *(.text) SCHED_TEXT LOCK_TEXT diff --git a/arch/sparc64/kernel/vmlinux.lds.S b/arch/sparc64/kernel/vmlinux.lds.S index bd9de8c2a2aa..4a6063f33e7a 100644 --- a/arch/sparc64/kernel/vmlinux.lds.S +++ b/arch/sparc64/kernel/vmlinux.lds.S @@ -13,6 +13,7 @@ SECTIONS . = 0x4000; .text 0x0000000000404000 : { + _text = .; *(.text) SCHED_TEXT LOCK_TEXT diff --git a/arch/v850/kernel/vmlinux.lds.S b/arch/v850/kernel/vmlinux.lds.S index 88d087f527c9..3a5fd07fe064 100644 --- a/arch/v850/kernel/vmlinux.lds.S +++ b/arch/v850/kernel/vmlinux.lds.S @@ -90,6 +90,7 @@ /* Kernel text segment, and some constant data areas. */ #define TEXT_CONTENTS \ + _text = .; \ __stext = . ; \ *(.text) \ SCHED_TEXT \ diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 22d281c6ec24..4c1ad0acbb4b 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -43,7 +43,7 @@ struct sym_entry { static struct sym_entry *table; static unsigned int table_size, table_cnt; -static unsigned long long _stext, _etext, _sinittext, _einittext, _sextratext, _eextratext; +static unsigned long long _text, _stext, _etext, _sinittext, _einittext, _sextratext, _eextratext; static int all_symbols = 0; static char symbol_prefix_char = '\0'; @@ -91,7 +91,9 @@ static int read_symbol(FILE *in, struct sym_entry *s) sym++; /* Ignore most absolute/undefined (?) symbols. */ - if (strcmp(sym, "_stext") == 0) + if (strcmp(sym, "_text") == 0) + _text = s->addr; + else if (strcmp(sym, "_stext") == 0) _stext = s->addr; else if (strcmp(sym, "_etext") == 0) _etext = s->addr; @@ -265,9 +267,21 @@ static void write_src(void) printf(".data\n"); + /* Provide proper symbols relocatability by their '_text' + * relativeness. The symbol names cannot be used to construct + * normal symbol references as the list of symbols contains + * symbols that are declared static and are private to their + * .o files. This prevents .tmp_kallsyms.o or any other + * object from referencing them. + */ output_label("kallsyms_addresses"); for (i = 0; i < table_cnt; i++) { - printf("\tPTR\t%#llx\n", table[i].addr); + if (toupper(table[i].sym[0]) != 'A') { + printf("\tPTR\t_text + %#llx\n", + table[i].addr - _text); + } else { + printf("\tPTR\t%#llx\n", table[i].addr); + } } printf("\n"); -- 2.20.1