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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

2
configure.ac
View file

@ -410,7 +410,7 @@ AC_SUBST([LIBLTDL])
AC_HEADER_STDC
# POSIX
AC_CHECK_HEADERS_ONCE([arpa/inet.h glob.h grp.h netdb.h netinet/in.h \
AC_CHECK_HEADERS_ONCE([arpa/inet.h cpuid.h glob.h grp.h netdb.h netinet/in.h \
netinet/in_systm.h netinet/tcp.h poll.h pwd.h sched.h \
sys/mman.h sys/select.h sys/socket.h sys/wait.h \
sys/uio.h syslog.h sys/dl.h dlfcn.h linux/sockios.h])

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;
}

37
src/pulsecore/cpu-x86.c
View file

@ -24,35 +24,28 @@
#include <stdint.h>
#ifdef HAVE_CPUID_H
#include <cpuid.h>
#endif
#include <pulsecore/log.h>
#include "cpu-x86.h"
#if defined (__i386__) || defined (__amd64__)
static void get_cpuid(uint32_t op, uint32_t *a, uint32_t *b, uint32_t *c, uint32_t *d) {
__asm__ __volatile__ (
" push %%"PA_REG_b" \n\t"
" cpuid \n\t"
" mov %%ebx, %%esi \n\t"
" pop %%"PA_REG_b" \n\t"
: "=a" (*a), "=S" (*b), "=c" (*c), "=d" (*d)
: "0" (op)
);
}
#endif
void pa_cpu_get_x86_flags(pa_cpu_x86_flag_t *flags) {
#if defined (__i386__) || defined (__amd64__)
#if (defined(__i386__) || defined(__amd64__)) && defined(HAVE_CPUID_H)
uint32_t eax, ebx, ecx, edx;
uint32_t level;
*flags = 0;
/* get standard level */
get_cpuid(0x00000000, &level, &ebx, &ecx, &edx);
if (__get_cpuid(0x00000000, &level, &ebx, &ecx, &edx) == 0)
goto finish;
if (level >= 1) {
get_cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
if (__get_cpuid(0x00000001, &eax, &ebx, &ecx, &edx) == 0)
goto finish;
if (edx & (1<<15))
*flags |= PA_CPU_X86_CMOV;
@ -80,9 +73,12 @@ void pa_cpu_get_x86_flags(pa_cpu_x86_flag_t *flags) {
}
/* get extended level */
get_cpuid(0x80000000, &level, &ebx, &ecx, &edx);
if (__get_cpuid(0x80000000, &level, &ebx, &ecx, &edx) == 0)
goto finish;
if (level >= 0x80000001) {
get_cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
if (__get_cpuid(0x80000001, &eax, &ebx, &ecx, &edx) == 0)
goto finish;
if (edx & (1<<22))
*flags |= PA_CPU_X86_MMXEXT;
@ -97,6 +93,7 @@ void pa_cpu_get_x86_flags(pa_cpu_x86_flag_t *flags) {
*flags |= PA_CPU_X86_3DNOW;
}
finish:
pa_log_info("CPU flags: %s%s%s%s%s%s%s%s%s%s%s",
(*flags & PA_CPU_X86_CMOV) ? "CMOV " : "",
(*flags & PA_CPU_X86_MMX) ? "MMX " : "",
@ -109,7 +106,7 @@ void pa_cpu_get_x86_flags(pa_cpu_x86_flag_t *flags) {
(*flags & PA_CPU_X86_MMXEXT) ? "MMXEXT " : "",
(*flags & PA_CPU_X86_3DNOW) ? "3DNOW " : "",
(*flags & PA_CPU_X86_3DNOWEXT) ? "3DNOWEXT " : "");
#endif /* defined (__i386__) || defined (__amd64__) */
#endif /* (defined(__i386__) || defined(__amd64__)) && defined(HAVE_CPUID_H) */
}
bool pa_cpu_init_x86(pa_cpu_x86_flag_t *flags) {

12
src/pulsecore/cpu-x86.h
View file

@ -43,20 +43,8 @@ bool pa_cpu_init_x86 (pa_cpu_x86_flag_t *flags);
#if defined (__i386__)
typedef int32_t pa_reg_x86;
#define PA_REG_a "eax"
#define PA_REG_b "ebx"
#define PA_REG_c "ecx"
#define PA_REG_d "edx"
#define PA_REG_D "edi"
#define PA_REG_S "esi"
#elif defined (__amd64__)
typedef int64_t pa_reg_x86;
#define PA_REG_a "rax"
#define PA_REG_b "rbx"
#define PA_REG_c "rcx"
#define PA_REG_d "rdx"
#define PA_REG_D "rdi"
#define PA_REG_S "rsi"
#endif
/* some optimized functions */