PPC64 needs some special logic to properly set up the TOC.
See commit 85baa095497f ("powerpc/livepatch: Add live patching support
on ppc64le") for details.
PPC32 doesn't have TOC so it doesn't need that logic, so adding
LIVEPATCH support is straight forward.
Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item.
Livepatch sample modules all work.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/Kconfig | 6 +++++-
arch/powerpc/include/asm/livepatch.h | 8 +++++---
arch/powerpc/include/asm/thread_info.h | 2 +-
arch/powerpc/kernel/asm-offsets.c | 2 +-
4 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 0631c9241af3..cdac2115eb00 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -9,6 +9,10 @@ config 64BIT
bool
default y if PPC64
+config LIVEPATCH_64
+ def_bool PPC64
+ depends on LIVEPATCH
+
config MMU
bool
default y
@@ -230,7 +234,7 @@ config PPC
select HAVE_KPROBES_ON_FTRACE
select HAVE_KRETPROBES
select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
- select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS && PPC64
+ select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_NMI if PERF_EVENTS || (PPC64 && PPC_BOOK3S)
select HAVE_OPTPROBES
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 4fe018cc207b..37af961eb74c 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -23,12 +23,14 @@ static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
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.
+ * Live patch works on PPC32 and only with -mprofile-kernel on PPC64. In
+ * both cases, the ftrace location is always within the first 16 bytes.
*/
return ftrace_location_range(faddr, faddr + 16);
}
+#endif /* CONFIG_LIVEPATCH */
+#ifdef CONFIG_LIVEPATCH_64
static inline void klp_init_thread_info(struct task_struct *p)
{
/* + 1 to account for STACK_END_MAGIC */
@@ -36,6 +38,6 @@ static inline void klp_init_thread_info(struct task_struct *p)
}
#else
static inline void klp_init_thread_info(struct task_struct *p) { }
-#endif /* CONFIG_LIVEPATCH */
+#endif
#endif /* _ASM_POWERPC_LIVEPATCH_H */
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 5725029aaa29..42f8a1f99036 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -51,7 +51,7 @@ struct thread_info {
unsigned int cpu;
#endif
unsigned long local_flags; /* private flags for thread */
-#ifdef CONFIG_LIVEPATCH
+#ifdef CONFIG_LIVEPATCH_64
unsigned long *livepatch_sp;
#endif
#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 7582f3e3a330..eec536aef83a 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -94,7 +94,7 @@ int main(void)
OFFSET(TASK_CPU, task_struct, thread_info.cpu);
#endif
-#ifdef CONFIG_LIVEPATCH
+#ifdef CONFIG_LIVEPATCH_64
OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
#endif
--
2.33.1
