[PATCH 1/7] kernel: call constructors
From: Peter Oberparleiter
Date: Mon May 19 2008 - 04:45:14 EST
From: Peter Oberparleiter <peter.oberparleiter@xxxxxxxxxx>
Call constructors during kernel init and module load. Required by the
gcov profiling infrastructure: gcc's profiling code uses constructors
to register profiling data structures.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@xxxxxxxxxx>
---
arch/powerpc/kernel/vmlinux.lds.S | 3 +++
include/asm-generic/sections.h | 1 +
include/asm-generic/vmlinux.lds.h | 5 +++++
include/linux/init.h | 2 ++
include/linux/module.h | 3 +++
init/main.c | 10 ++++++++++
kernel/module.c | 13 +++++++++++++
7 files changed, 37 insertions(+)
Index: linux-2.6.26-rc3/include/asm-generic/vmlinux.lds.h
===================================================================
--- linux-2.6.26-rc3.orig/include/asm-generic/vmlinux.lds.h
+++ linux-2.6.26-rc3/include/asm-generic/vmlinux.lds.h
@@ -352,3 +352,8 @@
*(.data.percpu.shared_aligned) \
} \
__per_cpu_end = .;
+
+#define CONSTRUCTORS \
+ VMLINUX_SYMBOL(__ctor_start) = .; \
+ *(.ctors) \
+ VMLINUX_SYMBOL(__ctor_end) = .;
Index: linux-2.6.26-rc3/arch/powerpc/kernel/vmlinux.lds.S
===================================================================
--- linux-2.6.26-rc3.orig/arch/powerpc/kernel/vmlinux.lds.S
+++ linux-2.6.26-rc3/arch/powerpc/kernel/vmlinux.lds.S
@@ -193,6 +193,9 @@ SECTIONS
*(.toc)
}
#endif
+ .data.gcov : {
+ CONSTRUCTORS
+ }
. = ALIGN(PAGE_SIZE);
_edata = .;
Index: linux-2.6.26-rc3/include/asm-generic/sections.h
===================================================================
--- linux-2.6.26-rc3.orig/include/asm-generic/sections.h
+++ linux-2.6.26-rc3/include/asm-generic/sections.h
@@ -13,5 +13,6 @@ extern char __per_cpu_start[], __per_cpu
extern char __kprobes_text_start[], __kprobes_text_end[];
extern char __initdata_begin[], __initdata_end[];
extern char __start_rodata[], __end_rodata[];
+extern char __ctor_start[], __ctor_end[];
#endif /* _ASM_GENERIC_SECTIONS_H_ */
Index: linux-2.6.26-rc3/include/linux/module.h
===================================================================
--- linux-2.6.26-rc3.orig/include/linux/module.h
+++ linux-2.6.26-rc3/include/linux/module.h
@@ -342,6 +342,9 @@ struct module
struct marker *markers;
unsigned int num_markers;
#endif
+ /* Constructor calls. */
+ ctorcall_t *ctors;
+ unsigned long num_ctors;
};
#ifndef MODULE_ARCH_INIT
#define MODULE_ARCH_INIT {}
Index: linux-2.6.26-rc3/kernel/module.c
===================================================================
--- linux-2.6.26-rc3.orig/kernel/module.c
+++ linux-2.6.26-rc3/kernel/module.c
@@ -1758,6 +1758,7 @@ static struct module *load_module(void _
unsigned int unusedgplcrcindex;
unsigned int markersindex;
unsigned int markersstringsindex;
+ unsigned int ctorsindex;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
@@ -1854,6 +1855,7 @@ static struct module *load_module(void _
#ifdef ARCH_UNWIND_SECTION_NAME
unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
+ ctorsindex = find_sec(hdr, sechdrs, secstrings, ".ctors");
/* Don't keep modinfo and version sections. */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
@@ -2064,6 +2066,8 @@ static struct module *load_module(void _
mod->num_markers =
sechdrs[markersindex].sh_size / sizeof(*mod->markers);
#endif
+ mod->ctors = (void *) sechdrs[ctorsindex].sh_addr;
+ mod->num_ctors = sechdrs[ctorsindex].sh_size / sizeof(*mod->ctors);
/* Find duplicate symbols */
err = verify_export_symbols(mod);
@@ -2176,6 +2180,14 @@ static struct module *load_module(void _
goto free_hdr;
}
+static void do_mod_ctors(struct module *mod)
+{
+ unsigned long i;
+
+ for (i = 0; i < mod->num_ctors; i++)
+ mod->ctors[i]();
+}
+
/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
@@ -2206,6 +2218,7 @@ sys_init_module(void __user *umod,
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
+ do_mod_ctors(mod);
/* Start the module */
if (mod->init != NULL)
ret = mod->init();
Index: linux-2.6.26-rc3/init/main.c
===================================================================
--- linux-2.6.26-rc3.orig/init/main.c
+++ linux-2.6.26-rc3/init/main.c
@@ -684,6 +684,15 @@ asmlinkage void __init start_kernel(void
rest_init();
}
+static void __init do_ctors(void)
+{
+ ctorcall_t *call;
+
+ for (call = (ctorcall_t *) __ctor_start;
+ call < (ctorcall_t *) __ctor_end; call++)
+ (*call)();
+}
+
static int __initdata initcall_debug;
static int __init initcall_debug_setup(char *str)
@@ -763,6 +772,7 @@ static void __init do_basic_setup(void)
usermodehelper_init();
driver_init();
init_irq_proc();
+ do_ctors();
do_initcalls();
}
Index: linux-2.6.26-rc3/include/linux/init.h
===================================================================
--- linux-2.6.26-rc3.orig/include/linux/init.h
+++ linux-2.6.26-rc3/include/linux/init.h
@@ -138,6 +138,8 @@ typedef void (*exitcall_t)(void);
extern initcall_t __con_initcall_start[], __con_initcall_end[];
extern initcall_t __security_initcall_start[], __security_initcall_end[];
+typedef void (*ctorcall_t)(void);
+
/* Defined in init/main.c */
extern char __initdata boot_command_line[];
extern char *saved_command_line;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/