Commit fd593d12 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Andi Kleen

[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: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 2a43f3ed
......@@ -70,6 +70,7 @@ SECTIONS
#endif
.text :
{
_text = .;
#if defined(CONFIG_ROMKERNEL)
*(.int_redirect)
#endif
......
......@@ -60,6 +60,7 @@ SECTIONS {
#endif
.text : {
_text = .;
_stext = . ;
*(.text)
SCHED_TEXT
......
......@@ -33,6 +33,7 @@ SECTIONS
/* Text and gots */
.text : {
_text = .;
*(.text .text.*)
SCHED_TEXT
LOCK_TEXT
......
......@@ -31,6 +31,7 @@ SECTIONS
.plt : { *(.plt) }
.text :
{
_text = .;
*(.text)
SCHED_TEXT
LOCK_TEXT
......
......@@ -11,6 +11,7 @@ SECTIONS
. = 0x10000 + SIZEOF_HEADERS;
.text 0xf0004000 :
{
_text = .;
*(.text)
SCHED_TEXT
LOCK_TEXT
......
......@@ -13,6 +13,7 @@ SECTIONS
. = 0x4000;
.text 0x0000000000404000 :
{
_text = .;
*(.text)
SCHED_TEXT
LOCK_TEXT
......
......@@ -90,6 +90,7 @@
/* Kernel text segment, and some constant data areas. */
#define TEXT_CONTENTS \
_text = .; \
__stext = . ; \
*(.text) \
SCHED_TEXT \
......
......@@ -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");
......
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