[PATCH 4/6] powerpc/livepatch: Add livepatch header
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2016-03-24 11:05:11
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), live patching, the rest · Maintainers:
Madhavan Srinivasan, Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Linus Torvalds
Add the powerpc specific livepatch definitions. In particular we provide a non-default implementation of klp_get_ftrace_location(). This is required because the location of the mcount call is not constant when using -mprofile-kernel (which we always do for live patching). Signed-off-by: Torsten Duwe <redacted> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/include/asm/livepatch.h | 54 ++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 arch/powerpc/include/asm/livepatch.h
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
new file mode 100644
index 000000000000..ad36e8e34fa1
--- /dev/null
+++ b/arch/powerpc/include/asm/livepatch.h@@ -0,0 +1,54 @@ +/* + * livepatch.h - powerpc-specific Kernel Live Patching Core + * + * Copyright (C) 2015-2016, SUSE, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#ifndef _ASM_POWERPC_LIVEPATCH_H +#define _ASM_POWERPC_LIVEPATCH_H + +#include <linux/module.h> +#include <linux/ftrace.h> + +#ifdef CONFIG_LIVEPATCH +static inline int klp_check_compiler_support(void) +{ + return 0; +} + +static inline int klp_write_module_reloc(struct module *mod, unsigned long + type, unsigned long loc, unsigned long value) +{ + /* This requires infrastructure changes; we need the loadinfos. */ + return -ENOSYS; +} + +static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) +{ + regs->nip = ip; +} + +#define klp_get_ftrace_location klp_get_ftrace_location +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) +{ + /* + * Live patch works only with -mprofile-kernel on PPC. In this case, + * the ftrace location is always within the first 16 bytes. + */ + return ftrace_location_range(faddr, faddr + 16); +} +#endif /* CONFIG_LIVEPATCH */ + +#endif /* _ASM_POWERPC_LIVEPATCH_H */
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2.5.0