[glibc] <sys/platform/x86.h>: Add Intel LAM support
H.J. Lu
hjl@sourceware.org
Tue Dec 22 11:46:09 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a2e5da2cf471b5ac849bcd7d9960466b9cd28a35
commit a2e5da2cf471b5ac849bcd7d9960466b9cd28a35
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Dec 21 19:56:10 2020 -0800
<sys/platform/x86.h>: Add Intel LAM support
Add Intel Linear Address Masking (LAM) support to <sys/platform/x86.h>.
HAS_CPU_FEATURE (LAM) can be used to detect if LAM is enabled in CPU.
LAM modifies the checking that is applied to 64-bit linear addresses,
allowing software to use of the untranslated address bits for metadata.
Diff:
---
manual/platform.texi | 3 +++
sysdeps/x86/sys/platform/x86.h | 3 +++
sysdeps/x86/tst-get-cpu-features.c | 1 +
3 files changed, 7 insertions(+)
diff --git a/manual/platform.texi b/manual/platform.texi
index 8fec2933d6..b67683aeb3 100644
--- a/manual/platform.texi
+++ b/manual/platform.texi
@@ -377,6 +377,9 @@ the indirect branch predictor barrier (IBPB).
@item
@code{KL} -- AES Key Locker instructions.
+@item
+@code{LAM} -- Linear Address Masking.
+
@item
@code{L1D_FLUSH} -- IA32_FLUSH_CMD MSR.
diff --git a/sysdeps/x86/sys/platform/x86.h b/sysdeps/x86/sys/platform/x86.h
index 3ef92b04e8..99d8c9b0ab 100644
--- a/sysdeps/x86/sys/platform/x86.h
+++ b/sysdeps/x86/sys/platform/x86.h
@@ -317,6 +317,7 @@ extern const struct cpu_features *__x86_get_cpu_features (unsigned int)
#define bit_cpu_FSRS (1u << 11)
#define bit_cpu_FSRCS (1u << 12)
#define bit_cpu_HRESET (1u << 22)
+#define bit_cpu_LAM (1u << 26)
/* COMMON_CPUID_INDEX_19. */
@@ -541,6 +542,7 @@ extern const struct cpu_features *__x86_get_cpu_features (unsigned int)
#define index_cpu_FSRS COMMON_CPUID_INDEX_7_ECX_1
#define index_cpu_FSRCS COMMON_CPUID_INDEX_7_ECX_1
#define index_cpu_HRESET COMMON_CPUID_INDEX_7_ECX_1
+#define index_cpu_LAM COMMON_CPUID_INDEX_7_ECX_1
/* COMMON_CPUID_INDEX_19. */
@@ -765,6 +767,7 @@ extern const struct cpu_features *__x86_get_cpu_features (unsigned int)
#define reg_FSRS eax
#define reg_FSRCS eax
#define reg_HRESET eax
+#define reg_LAM eax
/* COMMON_CPUID_INDEX_19. */
diff --git a/sysdeps/x86/tst-get-cpu-features.c b/sysdeps/x86/tst-get-cpu-features.c
index 667aa27117..6f1e925a6a 100644
--- a/sysdeps/x86/tst-get-cpu-features.c
+++ b/sysdeps/x86/tst-get-cpu-features.c
@@ -227,6 +227,7 @@ do_test (void)
CHECK_CPU_FEATURE (FSRS);
CHECK_CPU_FEATURE (FSRCS);
CHECK_CPU_FEATURE (HRESET);
+ CHECK_CPU_FEATURE (LAM);
CHECK_CPU_FEATURE (AESKLE);
CHECK_CPU_FEATURE (WIDE_KL);
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