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authorMasami Hiramatsu <mhiramat@redhat.com>2010-02-02 16:49:11 -0500
committerIngo Molnar <mingo@elte.hu>2010-02-04 09:36:19 +0100
commit2cfa19780d61740f65790c5bae363b759d7c96fa (patch)
treecc7a8277a9f04c1bd613efe03c7d6d16cd18dc96 /arch/x86/include/asm/alternative.h
parent615d0ebbc782b67296e3226c293f520f93f93515 (diff)
ftrace/alternatives: Introducing *_text_reserved functions
Introducing *_text_reserved functions for checking the text address range is partially reserved or not. This patch provides checking routines for x86 smp alternatives and dynamic ftrace. Since both functions modify fixed pieces of kernel text, they should reserve and protect those from other dynamic text modifier, like kprobes. This will also be extended when introducing other subsystems which modify fixed pieces of kernel text. Dynamic text modifiers should avoid those. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: przemyslaw@pawelczyk.it Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <20100202214911.4694.16587.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
-rw-r--r--arch/x86/include/asm/alternative.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 69b74a7b877f..ac80b7d70014 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -65,12 +65,17 @@ extern void alternatives_smp_module_add(struct module *mod, char *name,
void *text, void *text_end);
extern void alternatives_smp_module_del(struct module *mod);
extern void alternatives_smp_switch(int smp);
+extern int alternatives_text_reserved(void *start, void *end);
#else
static inline void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
void *text, void *text_end) {}
static inline void alternatives_smp_module_del(struct module *mod) {}
static inline void alternatives_smp_switch(int smp) {}
+static inline int alternatives_text_reserved(void *start, void *end)
+{
+ return 0;
+}
#endif /* CONFIG_SMP */
/* alternative assembly primitive: */