From f4b540e25c5c63fd55a80c78a22b2f69ecb848f8 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Tue, 30 Aug 2022 16:32:27 -0400 Subject: [PATCH] arm: smh: Fix uninitialized parameters with newer GCCs Newer versions of GCC won't initialize parts of structures which don't appear to be used. This results in uninitialized semihosting parameters passed via R1. Fix this by marking the inline assembly as clobbering memory. Signed-off-by: Sean Anderson --- arch/arm/lib/semihosting.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c index dbea2b0..01d652a 100644 --- a/arch/arm/lib/semihosting.c +++ b/arch/arm/lib/semihosting.c @@ -32,12 +32,12 @@ static noinline long smh_trap(unsigned int sysnum, void *addr) { register long result asm("r0"); #if defined(CONFIG_ARM64) - asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr)); + asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr) : "memory"); #elif defined(CONFIG_CPU_V7M) - asm volatile ("bkpt #0xAB" : "=r" (result) : "0"(sysnum), "r"(addr)); + asm volatile ("bkpt #0xAB" : "=r" (result) : "0"(sysnum), "r"(addr) : "memory"); #else /* Note - untested placeholder */ - asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr)); + asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr) : "memory"); #endif return result; } -- 2.7.4