Re: [RFC] [patch 1/2] add non_init_kernel_text_address

From: Srinivasa Ds
Date: Fri Dec 14 2007 - 04:31:22 EST


Resending the patch, by changing the name as suggested by Andrew.

Since __init functions are discarded and its memory freed once
initialization completes, It would be better if we enable kprobes
to refuse probing __init functions. The attached patchset will do
that.

This patch creates non_init_kernel_text_address() to identify
non_init text area.


Signed-off-by: Srinivasa DS <srinivasa@xxxxxxxxxx>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>



---
include/linux/kernel.h | 2 ++
kernel/extable.c | 16 +++++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)

Index: linux-2.6.24-rc5-mm1/include/linux/kernel.h
===================================================================
--- linux-2.6.24-rc5-mm1.orig/include/linux/kernel.h
+++ linux-2.6.24-rc5-mm1/include/linux/kernel.h
@@ -169,6 +169,8 @@ extern unsigned long long memparse(char
extern int core_kernel_text(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
+extern int regular_kernel_text_address(unsigned long addr);
+extern int non_init_core_kernel_text(unsigned long addr);
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);

Index: linux-2.6.24-rc5-mm1/kernel/extable.c
===================================================================
--- linux-2.6.24-rc5-mm1.orig/kernel/extable.c
+++ linux-2.6.24-rc5-mm1/kernel/extable.c
@@ -40,11 +40,18 @@ const struct exception_table_entry *sear
return e;
}

-int core_kernel_text(unsigned long addr)
+int non_init_core_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_stext &&
addr <= (unsigned long)_etext)
return 1;
+ return 0;
+}
+
+int core_kernel_text(unsigned long addr)
+{
+ if (non_init_core_kernel_text(addr))
+ return 1;

if (addr >= (unsigned long)_sinittext &&
addr <= (unsigned long)_einittext)
@@ -65,3 +72,10 @@ int kernel_text_address(unsigned long ad
return 1;
return module_text_address(addr) != NULL;
}
+
+int regular_kernel_text_address(unsigned long addr)
+{
+ if (non_init_core_kernel_text(addr))
+ return 1;
+ return module_text_address(addr) != NULL;
+}
--
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