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core-util, cpu-x86: use __get_cpuid() instead of homegrown assembly

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The get_cpuid() function in cpu-x86.c was buggy on x86-64. When building
without optimizations, the homegrown assembly code overwrote the
beginning of the function argument list on the stack. That happened to
work fine on regular x86-64, but caused crashing with the x32 ABI.

At least GCC and clang provide cpuid.h, which has the __get_cpuid()
function that can be used instead of the homegrown assembly.

The PA_REG_* constants can be removed as well, because they're not used
any more.

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=103656
This commit is contained in:
Tanu Kaskinen 2017-11-22 17:14:10 +02:00
parent 2062fc8b0e
commit c8bd93c5a7
4 changed files with 38 additions and 48 deletions
Download patch file Download diff file Expand all files Collapse all files

35
src/pulsecore/core-util.c
View file

@ -124,6 +124,10 @@
#include <sys/personality.h>
#endif
#ifdef HAVE_CPUID_H
#include <cpuid.h>
#endif
#include <pulse/xmalloc.h>
#include <pulse/util.h>
#include <pulse/utf8.h>
@ -136,7 +140,6 @@
#include <pulsecore/strbuf.h>
#include <pulsecore/usergroup.h>
#include <pulsecore/strlist.h>
#include <pulsecore/cpu-x86.h>
#include <pulsecore/pipe.h>
#include <pulsecore/once.h>
@ -3663,11 +3666,13 @@ bool pa_running_in_vm(void) {
/* Both CPUID and DMI are x86 specific interfaces... */
uint32_t eax = 0x40000000;
#ifdef HAVE_CPUID_H
uint32_t eax;
union {
uint32_t sig32[3];
char text[13];
} sig;
#endif
#ifdef __linux__
const char *const dmi_vendors[] = {
@ -3701,19 +3706,18 @@ bool pa_running_in_vm(void) {
#endif
/* http://lwn.net/Articles/301888/ */
#ifdef HAVE_CPUID_H
/* Hypervisors provide their signature on the 0x40000000 cpuid leaf.
* http://lwn.net/Articles/301888/
*
* XXX: Why are we checking a list of signatures instead of the
* "hypervisor present bit"? According to the LWN article, the "hypervisor
* present bit" would be available on bit 31 of ECX on leaf 0x1, and that
* bit would tell us directly whether we're in a virtual machine or not. */
pa_zero(sig);
__asm__ __volatile__ (
/* ebx/rbx is being used for PIC! */
" push %%"PA_REG_b" \n\t"
" cpuid \n\t"
" mov %%ebx, %1 \n\t"
" pop %%"PA_REG_b" \n\t"
: "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
: "0" (eax)
);
if (__get_cpuid(0x40000000, &eax, &sig.sig32[0], &sig.sig32[1], &sig.sig32[2]) == 0)
return false;
if (pa_streq(sig.text, "XenVMMXenVMM") ||
pa_streq(sig.text, "KVMKVMKVM") ||
@ -3722,8 +3726,9 @@ bool pa_running_in_vm(void) {
/* http://msdn.microsoft.com/en-us/library/bb969719.aspx */
pa_streq(sig.text, "Microsoft Hv"))
return true;
#endif /* HAVE_CPUID_H */
#endif
#endif /* defined(__i386__) || defined(__x86_64__) */
return false;
}