[PATCH BlueZ v2 4/4] tools/test-runner: Fix CPUID register clobbers
From: Pauli Virtanen <hidden>
Date: 2026-09-12 18:18:52
Subsystem:
the rest · Maintainer:
Linus Torvalds
CPUID modifies EAX, EBX, ECX and EDX, but the inline asm clobber list is incomplete. Use the __get_cpuid() intrinsic instead. Fixes rootfs_setup(r, argv) crashing due to impossible r != &rootfs due to clobbered registers. Assisted-by: qwen3.8-flash-next # finding the bug --- tools/test-runner.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/tools/test-runner.c b/tools/test-runner.c
index 9eaf39d35..2de05e26d 100644
--- a/tools/test-runner.c
+++ b/tools/test-runner.c@@ -33,6 +33,11 @@ #include <sys/param.h> #include <sys/reboot.h> +#if defined(__GNUC__) && (defined(__i386__) || defined(__amd64__)) +#include <cpuid.h> +#define HAVE_GET_CPUID +#endif + #include "bluetooth/bluetooth.h" #include "bluetooth/hci.h" #include "bluetooth/hci_lib.h"
@@ -306,12 +311,10 @@ static char *const qemu_envp[] = { static void check_virtualization(void) { -#if defined(__GNUC__) && (defined(__i386__) || defined(__amd64__)) - uint32_t ecx; +#ifdef HAVE_GET_CPUID + unsigned int eax, ebx, ecx, edx; - __asm__ __volatile__("cpuid" : "=c" (ecx) : "a" (1) : "memory"); - - if (!!(ecx & (1 << 5))) + if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) && (ecx & (1 << 5))) printf("Found support for Virtual Machine eXtensions\n"); #endif }
--
2.55.0