Commit-ID: d94a155c59c98c19b98ee949eaab6a0312bbd6be
Gitweb: https://git.kernel.org/tip/d94a155c59c98c19b98ee949eaab6a0312bbd6be
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Tue, 10 Apr 2018 12:27:04 +0300
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 10 Apr 2018 16:33:21 +0200
x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption
Some features (Intel MKTME, AMD SME) reduce the number of effectively
available physical address bits. cpuinfo_x86::x86_phys_bits is adjusted
accordingly during the early cpu feature detection.
Though if get_cpu_cap() is called later again then this adjustement is
overwritten. That happens in setup_pku(), which is called after
detect_tme().
To address this, extract the address sizes enumeration into a separate
function, which is only called only from early_identify_cpu() and from
generic_identify().
This makes get_cpu_cap() safe to be called later during boot proccess
without overwriting cpuinfo_x86::x86_phys_bits.
[ tglx: Massaged changelog ]
Fixes: cb06d8e3d020 ("x86/tme: Detect if TME and MKTME is activated by BIOS")
Reported-by: Kai Huang <kai.huang@xxxxxxxxxxxxxxx>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20180410092704.41106-1-kirill.shutemov@xxxxxxxxxxxxxxx
---
arch/x86/kernel/cpu/common.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 348cf4821240..2981bf287ef5 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -848,18 +848,6 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
c->x86_power = edx;
}
- if (c->extended_cpuid_level >= 0x80000008) {
- cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
-
- c->x86_virt_bits = (eax >> 8) & 0xff;
- c->x86_phys_bits = eax & 0xff;
- c->x86_capability[CPUID_8000_0008_EBX] = ebx;
- }
-#ifdef CONFIG_X86_32
- else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
- c->x86_phys_bits = 36;
-#endif
-
if (c->extended_cpuid_level >= 0x8000000a)
c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
@@ -874,6 +862,23 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
apply_forced_caps(c);
}
+static void get_cpu_address_sizes(struct cpuinfo_x86 *c)
+{
+ u32 eax, ebx, ecx, edx;
+
+ if (c->extended_cpuid_level >= 0x80000008) {
+ cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
+
+ c->x86_virt_bits = (eax >> 8) & 0xff;
+ c->x86_phys_bits = eax & 0xff;
+ c->x86_capability[CPUID_8000_0008_EBX] = ebx;
+ }
+#ifdef CONFIG_X86_32
+ else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
+ c->x86_phys_bits = 36;
+#endif
+}
+
static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
@@ -965,6 +970,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
cpu_detect(c);
get_cpu_vendor(c);
get_cpu_cap(c);
+ get_cpu_address_sizes(c);
setup_force_cpu_cap(X86_FEATURE_CPUID);
if (this_cpu->c_early_init)
@@ -1097,6 +1103,8 @@ static void generic_identify(struct cpuinfo_x86 *c)
get_cpu_cap(c);
+ get_cpu_address_sizes(c);
+
if (c->cpuid_level >= 0x00000001) {
c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
#ifdef CONFIG_X86_32
--
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