From 7845b91dbc7690064a2be6df690e4aaba728fb04 Mon Sep 17 00:00:00 2001
From: Mike Frysinger
Date: Tue, 5 Aug 2014 18:59:50 -0400
Subject: lscpu: clean up vmware inline asm

This code is not PIC clean which means it fails to build on hardened
32bit x86 systems (i.e. building as PIE).

While here, optimize the existing cpuid logic slightly.

URL: https://bugs.gentoo.org/518936
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 sys-utils/lscpu.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

(limited to 'sys-utils/lscpu.c')

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 062dff501..9965eeb65 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -546,10 +546,9 @@ cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx,
 	__asm__(
 #if defined(__PIC__) && defined(__i386__)
 		/* x86 PIC cannot clobber ebx -- gcc bitches */
-		"pushl %%ebx;"
+		"xchg %%ebx, %%esi;"
 		"cpuid;"
-		"movl %%ebx, %%esi;"
-		"popl %%ebx;"
+		"xchg %%esi, %%ebx;"
 		: "=S" (*ebx),
 #else
 		"cpuid;"
@@ -656,12 +655,29 @@ read_hypervisor_powerpc(struct lscpu_desc *desc)
 #define VMWARE_BDOOR_PORT           0x5658
 #define VMWARE_BDOOR_CMD_GETVERSION 10
 
-#define VMWARE_BDOOR(eax, ebx, ecx, edx)                                  \
-        __asm__("inl (%%dx), %%eax" :                                     \
-               "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) :               \
-               "0"(VMWARE_BDOOR_MAGIC), "1"(VMWARE_BDOOR_CMD_GETVERSION), \
-               "2"(VMWARE_BDOOR_PORT), "3"(0) :                           \
-               "memory");
+static inline
+void vmware_bdoor(uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
+{
+	__asm__(
+#if defined(__PIC__) && defined(__i386__)
+		/* x86 PIC cannot clobber ebx -- gcc bitches */
+		"xchg %%ebx, %%esi;"
+		"inl (%%dx), %%eax;"
+		"xchg %%esi, %%ebx;"
+		: "=S" (*ebx),
+#else
+		"inl (%%dx), %%eax;"
+		: "=b" (*ebx),
+#endif
+		  "=a" (*eax),
+		  "=c" (*ecx),
+		  "=d" (*edx)
+		: "0" (VMWARE_BDOOR_MAGIC),
+		  "1" (VMWARE_BDOOR_CMD_GETVERSION),
+		  "2" (VMWARE_BDOOR_PORT),
+		  "3" (0)
+		: "memory");
+}
 
 static jmp_buf segv_handler_env;
 
@@ -697,7 +713,7 @@ is_vmware_platform(void)
 	if (sigaction(SIGSEGV, &act, &oact))
 		err(EXIT_FAILURE, _("error: can not set signal handler"));
 
-	VMWARE_BDOOR(eax, ebx, ecx, edx);
+	vmware_bdoor(&eax, &ebx, &ecx, &edx);
 
 	if (sigaction(SIGSEGV, &oact, NULL))
 		err(EXIT_FAILURE, _("error: can not restore signal handler"));
-- 
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