summaryrefslogtreecommitdiff
path: root/arch/x86/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/cpu/bugs.c4
-rw-r--r--arch/x86/kernel/cpu/intel.c3
-rw-r--r--arch/x86/kernel/process_64.c1
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 34e4aaaf03d2..b9e6b60df148 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -654,6 +654,10 @@ static void __init l1tf_select_mitigation(void)
half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
if (e820_any_mapped(half_pa, ULLONG_MAX - half_pa, E820_RAM)) {
pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
+ pr_info("You may make it effective by booting the kernel with mem=%llu parameter.\n",
+ half_pa);
+ pr_info("However, doing so will make a part of your RAM unusable.\n");
+ pr_info("Reading https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html might help you decide.\n");
return;
}
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 4dce22d3cb06..b18fe3d245fe 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -74,6 +74,9 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_HYPERVISOR))
return false;
+ if (c->x86 != 6)
+ return false;
+
for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
if (c->x86_model == spectre_bad_microcodes[i].model &&
c->x86_mask == spectre_bad_microcodes[i].stepping)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 4cbb60fbff3e..c7cc81e9bb84 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -250,6 +250,7 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
start_thread_common(regs, new_ip, new_sp,
__USER_CS, __USER_DS, 0);
}
+EXPORT_SYMBOL_GPL(start_thread);
#ifdef CONFIG_COMPAT
void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp)