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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-26 09:34:21 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-26 09:34:21 -0800
commit85a2d939c05965ab9e849735436a3c8d3538dc75 (patch)
treeba5436dc3c687dc84b22536824b68ab413fc7c4a /kernel
parentd4858aaf6bd8a90e2dacc0dfec2077e334dcedbf (diff)
parent946fbbc13dce68902f64515b610eeb2a6c3d7a64 (diff)
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Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "Yet another pile of melted spectrum related changes: - sanitize the array_index_nospec protection mechanism: Remove the overengineered array_index_nospec_mask_check() magic and allow const-qualified types as index to avoid temporary storage in a non-const local variable. - make the microcode loader more robust by properly propagating error codes. Provide information about new feature bits after micro code was updated so administrators can act upon. - optimizations of the entry ASM code which reduce code footprint and make the code simpler and faster. - fix the {pmd,pud}_{set,clear}_flags() implementations to work properly on paravirt kernels by removing the address translation operations. - revert the harmful vmexit_fill_RSB() optimization - use IBRS around firmware calls - teach objtool about retpolines and add annotations for indirect jumps and calls. - explicitly disable jumplabel patching in __init code and handle patching failures properly instead of silently ignoring them. - remove indirect paravirt calls for writing the speculation control MSR as these calls are obviously proving the same attack vector which is tried to be mitigated. - a few small fixes which address build issues with recent compiler and assembler versions" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely() KVM/x86: Remove indirect MSR op calls from SPEC_CTRL objtool, retpolines: Integrate objtool with retpoline support more closely x86/entry/64: Simplify ENCODE_FRAME_POINTER extable: Make init_kernel_text() global jump_label: Warn on failed jump_label patching attempt jump_label: Explicitly disable jump labels in __init code x86/entry/64: Open-code switch_to_thread_stack() x86/entry/64: Move ASM_CLAC to interrupt_entry() x86/entry/64: Remove 'interrupt' macro x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry() x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP objtool: Add module specific retpoline rules objtool: Add retpoline validation objtool: Use existing global variables for options x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute() x86/boot, objtool: Annotate indirect jump in secondary_startup_64() x86/paravirt, objtool: Annotate indirect calls ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/extable.c2
-rw-r--r--kernel/jump_label.c27
2 files changed, 23 insertions, 6 deletions
diff --git a/kernel/extable.c b/kernel/extable.c
index a17fdb63dc3e..6a5b61ebc66c 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -64,7 +64,7 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
return e;
}
-static inline int init_kernel_text(unsigned long addr)
+int init_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_sinittext &&
addr < (unsigned long)_einittext)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index b4517095db6a..52a0a7af8640 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -366,12 +366,15 @@ static void __jump_label_update(struct static_key *key,
{
for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
/*
- * entry->code set to 0 invalidates module init text sections
- * kernel_text_address() verifies we are not in core kernel
- * init code, see jump_label_invalidate_module_init().
+ * An entry->code of 0 indicates an entry which has been
+ * disabled because it was in an init text area.
*/
- if (entry->code && kernel_text_address(entry->code))
- arch_jump_label_transform(entry, jump_label_type(entry));
+ if (entry->code) {
+ if (kernel_text_address(entry->code))
+ arch_jump_label_transform(entry, jump_label_type(entry));
+ else
+ WARN_ONCE(1, "can't patch jump_label at %pS", (void *)entry->code);
+ }
}
}
@@ -417,6 +420,19 @@ void __init jump_label_init(void)
cpus_read_unlock();
}
+/* Disable any jump label entries in __init code */
+void __init jump_label_invalidate_init(void)
+{
+ struct jump_entry *iter_start = __start___jump_table;
+ struct jump_entry *iter_stop = __stop___jump_table;
+ struct jump_entry *iter;
+
+ for (iter = iter_start; iter < iter_stop; iter++) {
+ if (init_kernel_text(iter->code))
+ iter->code = 0;
+ }
+}
+
#ifdef CONFIG_MODULES
static enum jump_label_type jump_label_init_type(struct jump_entry *entry)
@@ -633,6 +649,7 @@ static void jump_label_del_module(struct module *mod)
}
}
+/* Disable any jump label entries in module init code */
static void jump_label_invalidate_module_init(struct module *mod)
{
struct jump_entry *iter_start = mod->jump_entries;