[PATCH] powerpc/pseries/mce: Avoid instrumentation in realmode

* [PATCH] powerpc/pseries/mce: Avoid instrumentation in realmode
@ 2022-08-29  7:45 Ganesh Goudar
  2022-08-29 11:32 ` Sachin Sant
  0 siblings, 1 reply; 3+ messages in thread
From: Ganesh Goudar @ 2022-08-29  7:45 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Ganesh Goudar, mahesh, sachinp

Part of machine check error handling is done in realmode,
As of now instrumentation is not possible for any code that
runs in realmode.
When MCE is injected on KASAN enabled kernel, crash is
observed, Hence force inline or mark no instrumentation
for functions which can run in realmode to avoid KASAN
instrumentation.

Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
---
 arch/powerpc/include/asm/interrupt.h | 2 +-
 arch/powerpc/include/asm/rtas.h      | 4 ++--
 arch/powerpc/kernel/rtas.c           | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 8069dbc4b8d1..090895051712 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -92,7 +92,7 @@ static inline bool is_implicit_soft_masked(struct pt_regs *regs)
 	return search_kernel_soft_mask_table(regs->nip);
 }
 
-static inline void srr_regs_clobbered(void)
+static __always_inline void srr_regs_clobbered(void)
 {
 	local_paca->srr_valid = 0;
 	local_paca->hsrr_valid = 0;
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 00531af17ce0..52d29d664fdf 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -201,13 +201,13 @@ inline uint32_t rtas_ext_event_company_id(struct rtas_ext_event_log_v6 *ext_log)
 #define PSERIES_ELOG_SECT_ID_MCE		(('M' << 8) | 'C')
 
 static
-inline uint16_t pseries_errorlog_id(struct pseries_errorlog *sect)
+__always_inline uint16_t pseries_errorlog_id(struct pseries_errorlog *sect)
 {
 	return be16_to_cpu(sect->id);
 }
 
 static
-inline uint16_t pseries_errorlog_length(struct pseries_errorlog *sect)
+__always_inline uint16_t pseries_errorlog_length(struct pseries_errorlog *sect)
 {
 	return be16_to_cpu(sect->length);
 }
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 693133972294..f9d78245c0e8 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -48,7 +48,7 @@
 /* This is here deliberately so it's only used in this file */
 void enter_rtas(unsigned long);
 
-static inline void do_enter_rtas(unsigned long args)
+static __always_inline void do_enter_rtas(unsigned long args)
 {
 	unsigned long msr;
 
@@ -435,7 +435,7 @@ static char *__fetch_rtas_last_error(char *altbuf)
 #endif
 
 
-static void
+noinstr static void
 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
 		      va_list list)
 {
-- 
2.37.1


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