Commit 56e33afd authored by Jiri Kosina's avatar Jiri Kosina Committed by Steven Rostedt (VMware)
Browse files

livepatch: Remove klp_check_compiler_support() 

The only purpose of klp_check_compiler_support() is to make sure that we
are not using ftrace on x86 via mcount (because that's executed only after
prologue has already happened, and that's too late for livepatching
purposes).

Now that mcount is not supported by ftrace any more, there is no need for
klp_check_compiler_support() either.

Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1905102346100.17054@cbobk.fhfr.pm



Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 562e14f7

arch/powerpc/include/asm/livepatch.h

+0 −5
Original line number Diff line number Diff line
@@ -24,11 +24,6 @@ 
#include <linux/sched/task_stack.h>



#ifdef CONFIG_LIVEPATCH

static inline int klp_check_compiler_support(void)

{

	return 0;

}



static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)

{

	regs->nip = ip;

arch/s390/include/asm/livepatch.h

+0 −5
Original line number Diff line number Diff line
@@ -13,11 +13,6 @@ 


#include <asm/ptrace.h>



static inline int klp_check_compiler_support(void)

{

	return 0;

}



static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)

{

	regs->psw.addr = ip;

arch/x86/include/asm/livepatch.h

+0 −5
Original line number Diff line number Diff line
@@ -24,11 +24,6 @@ 
#include <asm/setup.h>

#include <linux/ftrace.h>



static inline int klp_check_compiler_support(void)

{

	return 0;

}



static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)

{

	regs->ip = ip;

kernel/livepatch/core.c

+0 −8
Original line number Diff line number Diff line
@@ -1220,14 +1220,6 @@ void klp_module_going(struct module *mod) 


static int __init klp_init(void)

{

	int ret;



	ret = klp_check_compiler_support();

	if (ret) {

		pr_info("Your compiler is too old; turning off.\n");

		return -EINVAL;

	}



	klp_root_kobj = kobject_create_and_add("livepatch", kernel_kobj);

	if (!klp_root_kobj)

		return -ENOMEM;

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