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authorArnd Bergmann <arnd@arndb.de>2019-05-14 15:41:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 19:52:48 -0700
commitbe167862ae7dd85c56d385209a4890678e1b0488 (patch)
treefcd77dcc6f471ece8447574203181ea7c038afed /arch
parent687a3e4d8e6129f064711291f1564d95472dba3e (diff)
downloadlinux-be167862ae7dd85c56d385209a4890678e1b0488.tar.bz2
ARM: prevent tracing IPI_CPU_BACKTRACE
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. [yamada.masahiro@socionext.com: rebase on v5.1-rc1] Link: http://lkml.kernel.org/r/20190423034959.13525-2-yamada.masahiro@socionext.com 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 <arnd@arndb.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Mathieu Malaterre <malat@debian.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stefan Agner <stefan@agner.ch> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Richard Weinberger <richard@nod.at> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Borislav Petkov <bp@suse.de> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/hardirq.h1
-rw-r--r--arch/arm/kernel/smp.c6
2 files changed, 6 insertions, 1 deletions
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 facd4240ca02..c93fe0f256de 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -70,6 +70,10 @@ 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
@@ -797,7 +801,7 @@ 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)