From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: [PATCH] elf: Fix tst-cpu-features-cpuinfo on some ADM systems (BZ #28090)
Date: Thu, 15 Jul 2021 08:58:04 -0300 [thread overview]
Message-ID: <20210715115804.4192826-1-adhemerval.zanella@linaro.org> (raw)
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_ssdb'.
Checked on x86_64-linux-gnu on a Ryzen 9 5900x.
---
sysdeps/x86/bits/platform/x86.h | 1 +
sysdeps/x86/include/cpu-features.h | 3 +++
sysdeps/x86/tst-cpu-features-cpuinfo.c | 13 ++++++++++++-
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/sysdeps/x86/bits/platform/x86.h b/sysdeps/x86/bits/platform/x86.h
index 5509b1ad87..2b257606b2 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 59e01df543..a3f11baa7a 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 f457e8677b..9d4ae65e26 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 'ssdb'
+ and 'virt_ssdb' on /proc/cpuinfo; while for AMD_SSBD only 'ssdb'
+ 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);
--
2.30.2
next reply other threads:[~2021-07-15 11:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-15 11:58 Adhemerval Zanella [this message]
2021-07-15 12:39 ` H.J. Lu
2021-07-19 16:42 ` Adhemerval Zanella
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