[ Upstream commit be167862ae7dd85c56d385209a4890678e1b0488 ]
Patch series "compiler: allow all arches to enable
CONFIG_OPTIMIZE_INLINING", v3.
This patch (of 11):
When function tracing for IPIs is enabled, we get a warning for an
overflow of the ipi_types array with the IPI_CPU_BACKTRACE type as
triggered by raise_nmi():
arch/arm/kernel/smp.c: In function 'raise_nmi':
arch/arm/kernel/smp.c:489:2: error: array subscript is above array bounds
[-Werror=array-bounds]
trace_ipi_raise(target, ipi_types[ipinr]);
This is a correct warning as we actually overflow the array here.
This patch raise_nmi() to call __smp_cross_call() instead of
smp_cross_call(), to avoid calling into ftrace. For clarification, I'm
also adding a two new code comments describing how this one is special.
The warning appears to have shown up after commit e7273ff49acf ("ARM:
8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI"), which changed the
number assignment from '15' to '8', but as far as I can tell has existed
since the IPI tracepoints were first introduced. If we decide to
backport this patch to stable kernels, we probably need to backport
e7273ff49acf as well.
[[email protected]: rebase on v5.1-rc1]
Link:
http://lkml.kernel.org/r/[email protected]
Fixes: e7273ff49acf ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI")
Fixes: 365ec7b17327 ("ARM: add IPI tracepoints") # v3.17
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Stefan Agner <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Miquel Raynal <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Brian Norris <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Russell King <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Mark Rutland <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
arch/arm/include/asm/hardirq.h | 1 +
arch/arm/kernel/smp.c | 6 +++++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h
index cba23eaa6072..7a88f160b1fb 100644
--- a/arch/arm/include/asm/hardirq.h
+++ b/arch/arm/include/asm/hardirq.h
@@ -6,6 +6,7 @@
#include <linux/threads.h>
#include <asm/irq.h>
+/* number of IPIS _not_ including IPI_CPU_BACKTRACE */
#define NR_IPI 7
typedef struct {
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index a3ce7c5365fa..bada66ef4419 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -76,6 +76,10 @@ enum ipi_msg_type {
IPI_CPU_STOP,
IPI_IRQ_WORK,
IPI_COMPLETION,
+ /*
+ * CPU_BACKTRACE is special and not included in NR_IPI
+ * or tracable with trace_ipi_*
+ */
IPI_CPU_BACKTRACE,
/*
* SGI8-15 can be reserved by secure firmware, and thus may
@@ -803,7 +807,7 @@ core_initcall(register_cpufreq_notifier);
static void raise_nmi(cpumask_t *mask)
{
- smp_cross_call(mask, IPI_CPU_BACKTRACE);
+ __smp_cross_call(mask, IPI_CPU_BACKTRACE);
}
void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
--
2.20.1
