From: "H.J. Lu" <hjl.tools@gmail.com>
To: DJ Delorie <dj@redhat.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: tunables vs osxsave vs checkpointing vs _dl_runtime_resolve
Date: Thu, 18 Mar 2021 21:16:27 -0700 [thread overview]
Message-ID: <CAMe9rOoNBoWHoYnkyQgQVOF0oSHTBE08xT5gT30Fhaq7BF5YSA@mail.gmail.com> (raw)
In-Reply-To: <xnlfajn749.fsf@rhel8.vm>
[-- Attachment #1: Type: text/plain, Size: 424 bytes --]
On Thu, Mar 18, 2021 at 8:40 PM DJ Delorie <dj@redhat.com> wrote:
>
>
> But...
>
> (gdb) set env GLIBC_TUNABLES=glibc.cpu.hwcaps=-OSXSAVE
> (gdb) r
> The program being debugged has been started already.
> Start it from the beginning? (y or n) y
> Starting program: /home/dj/criu-test
>
> Breakpoint 2, _dl_runtime_resolve_xsavec () at ../sysdeps/x86_64/dl-trampoline.h:67
> 67 _CET_ENDBR
>
Try this.
--
H.J.
[-- Attachment #2: cpu-features.diff --]
[-- Type: text/x-patch, Size: 2447 bytes --]
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index d7248cbb45..6262b03cd4 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -40,7 +40,7 @@ extern void TUNABLE_CALLBACK (set_x86_shstk) (tunable_val_t *)
#endif
static void
-update_usable (struct cpu_features *cpu_features)
+copy_usable (struct cpu_features *cpu_features)
{
/* Copy the cpuid bits to usable bits for CPU featuress whose usability
in user space can be detected without additonal OS support. */
@@ -98,9 +98,13 @@ update_usable (struct cpu_features *cpu_features)
CPU_FEATURE_SET_USABLE (cpu_features, FSRS);
CPU_FEATURE_SET_USABLE (cpu_features, FSRCS);
CPU_FEATURE_SET_USABLE (cpu_features, PTWRITE);
+}
+static void
+update_usable (struct cpu_features *cpu_features)
+{
/* Can we call xgetbv? */
- if (CPU_FEATURES_CPU_P (cpu_features, OSXSAVE))
+ if (CPU_FEATURE_USABLE_P (cpu_features, OSXSAVE))
{
unsigned int xcrlow;
unsigned int xcrhigh;
@@ -420,8 +424,6 @@ init_cpu_features (struct cpu_features *cpu_features)
get_extended_indices (cpu_features);
- update_usable (cpu_features);
-
if (family == 0x06)
{
model += extended_model;
@@ -547,8 +549,6 @@ init_cpu_features (struct cpu_features *cpu_features)
get_extended_indices (cpu_features);
- update_usable (cpu_features);
-
ecx = cpu_features->features[CPUID_INDEX_1].cpuid.ecx;
if (CPU_FEATURE_USABLE_P (cpu_features, AVX))
@@ -586,8 +586,6 @@ init_cpu_features (struct cpu_features *cpu_features)
get_extended_indices (cpu_features);
- update_usable (cpu_features);
-
model += extended_model;
if (family == 0x6)
{
@@ -630,7 +628,6 @@ init_cpu_features (struct cpu_features *cpu_features)
{
kind = arch_kind_other;
get_common_indices (cpu_features, NULL, NULL, NULL, NULL);
- update_usable (cpu_features);
}
/* Support i586 if CX8 is available. */
@@ -652,6 +649,8 @@ no_cpuid:
dl_init_cacheinfo (cpu_features);
+ copy_usable (cpu_features);
+
#if HAVE_TUNABLES
TUNABLE_GET (hwcaps, tunable_val_t *, TUNABLE_CALLBACK (set_hwcaps));
#elif defined SHARED
@@ -661,6 +660,8 @@ no_cpuid:
GLRO(dl_hwcap_mask) = HWCAP_IMPORTANT;
#endif
+ update_usable (cpu_features);
+
#ifdef __x86_64__
GLRO(dl_hwcap) = HWCAP_X86_64;
if (cpu_features->basic.kind == arch_kind_intel)
next prev parent reply other threads:[~2021-03-19 4:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 17:18 DJ Delorie
2021-03-18 17:29 ` H.J. Lu
2021-03-18 17:45 ` DJ Delorie
2021-03-18 20:39 ` H.J. Lu
2021-03-19 3:40 ` DJ Delorie
2021-03-19 4:16 ` H.J. Lu [this message]
2021-03-19 4:35 ` DJ Delorie
2021-03-18 17:32 ` Florian Weimer
2021-03-18 17:47 ` DJ Delorie
2021-03-18 17:57 ` Florian Weimer
2021-03-18 18:19 ` DJ Delorie
2021-03-19 16:43 ` Szabolcs Nagy
2021-03-19 21:12 ` DJ Delorie
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