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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-07-15 08:52:44 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-07-19 14:12:29 -0300
commit469761eac842663365bba3dacd4cdf15a2ae328d (patch)
tree570826e6942f9bc0bb7eec6bb34dedec141e0d01 /sysdeps/x86
parent5adb0e14a5cc9e011e58a7aaf193b598ecbd7b07 (diff)
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elf: Fix tst-cpu-features-cpuinfo on some AMD systems (BZ #28090)
The SSBD feature is implemented in 2 different ways on AMD processors: newer systems (Zen3) provides AMD_SSBD (function 8000_0008, EBX[24]), while older system provides AMD_VIRT_SSBD (function 8000_0008, EBX[25]). However for AMD_VIRT_SSBD, kernel shows both 'ssdb' and 'virt_ssdb' on /proc/cpuinfo; while for AMD_SSBD only 'ssdb' is provided. This now check is AMD_SSBD is set to check for 'ssbd', otherwise check if AMD_VIRT_SSDB is set to check for 'virt_ssbd'. Checked on x86_64-linux-gnu on a Ryzen 9 5900x. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Diffstat (limited to 'sysdeps/x86')
-rw-r--r--sysdeps/x86/bits/platform/x86.h1
-rw-r--r--sysdeps/x86/include/cpu-features.h3
-rw-r--r--sysdeps/x86/tst-cpu-features-cpuinfo.c13
3 files changed, 16 insertions, 1 deletions
diff --git a/sysdeps/x86/bits/platform/x86.h b/sysdeps/x86/bits/platform/x86.h
index 5509b1a..2b25760 100644
--- a/sysdeps/x86/bits/platform/x86.h
+++ b/sysdeps/x86/bits/platform/x86.h
@@ -282,6 +282,7 @@ enum
x86_cpu_AMD_IBRS = x86_cpu_index_80000008_ebx + 14,
x86_cpu_AMD_STIBP = x86_cpu_index_80000008_ebx + 15,
x86_cpu_AMD_SSBD = x86_cpu_index_80000008_ebx + 24,
+ x86_cpu_AMD_VIRT_SSBD = x86_cpu_index_80000008_ebx + 25,
x86_cpu_index_7_ecx_1_eax
= (CPUID_INDEX_7_ECX_1 * 8 * 4 * sizeof (unsigned int)
diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
index 59e01df..a3f11ba 100644
--- a/sysdeps/x86/include/cpu-features.h
+++ b/sysdeps/x86/include/cpu-features.h
@@ -293,6 +293,7 @@ enum
#define bit_cpu_AMD_IBRS (1u << 14)
#define bit_cpu_AMD_STIBP (1u << 15)
#define bit_cpu_AMD_SSBD (1u << 24)
+#define bit_cpu_AMD_VIRT_SSBD (1u << 25)
/* CPUID_INDEX_7_ECX_1. */
@@ -527,6 +528,7 @@ enum
#define index_cpu_AMD_IBRS CPUID_INDEX_80000008
#define index_cpu_AMD_STIBP CPUID_INDEX_80000008
#define index_cpu_AMD_SSBD CPUID_INDEX_80000008
+#define index_cpu_AMD_VIRT_SSBD CPUID_INDEX_80000008
/* CPUID_INDEX_7_ECX_1. */
@@ -761,6 +763,7 @@ enum
#define reg_AMD_IBRS ebx
#define reg_AMD_STIBP ebx
#define reg_AMD_SSBD ebx
+#define reg_AMD_VIRT_SSBD ebx
/* CPUID_INDEX_7_ECX_1. */
diff --git a/sysdeps/x86/tst-cpu-features-cpuinfo.c b/sysdeps/x86/tst-cpu-features-cpuinfo.c
index f457e86..76bf5b2 100644
--- a/sysdeps/x86/tst-cpu-features-cpuinfo.c
+++ b/sysdeps/x86/tst-cpu-features-cpuinfo.c
@@ -236,7 +236,18 @@ do_test (int argc, char **argv)
if (cpu_features->basic.kind == arch_kind_intel)
fails += CHECK_PROC (ssbd, SSBD);
else if (cpu_features->basic.kind == arch_kind_amd)
- fails += CHECK_PROC (ssbd, AMD_SSBD);
+ {
+ /* This feature is implemented in 2 different ways on AMD processors:
+ newer systems provides AMD_SSBD (function 8000_0008, EBX[24]),
+ while older system proviseds AMD_VIRT_SSBD (function 8000_008,
+ EBX[25]). However for AMD_VIRT_SSBD, kernel shows both 'ssbd'
+ and 'virt_ssbd' on /proc/cpuinfo; while for AMD_SSBD only 'ssbd'
+ is provided. */
+ if (HAS_CPU_FEATURE (AMD_SSBD))
+ fails += CHECK_PROC (ssbd, AMD_SSBD);
+ else if (HAS_CPU_FEATURE (AMD_VIRT_SSBD))
+ fails += CHECK_PROC (virt_ssbd, AMD_VIRT_SSBD);
+ }
fails += CHECK_PROC (sse, SSE);
fails += CHECK_PROC (sse2, SSE2);
fails += CHECK_PROC (pni, SSE3);