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| author | Peter Zijlstra <peterz@infradead.org> | 2022-03-08 18:30:40 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-03-15 12:32:40 +0300 |
| commit | 3e3f069504344c241f89737e4af014f83fca0b27 (patch) | |
| tree | 688a7a7c08057f42a4020b1a425ad4f5f528ae36 /arch/x86/kernel | |
| parent | fe379fa4d199abc52d5b4a256e52cf94eff685cf (diff) | |
| download | linux-3e3f069504344c241f89737e4af014f83fca0b27.tar.xz | |
x86/ibt: Annotate text references
Annotate away some of the generic code references. This is things
where we take the address of a symbol for exception handling or return
addresses (eg. context switch).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.877758523@infradead.org
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 2 |
4 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 14d1003328e9..954d39c15724 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -713,6 +713,7 @@ asm ( " .pushsection .init.text, \"ax\", @progbits\n" " .type int3_magic, @function\n" "int3_magic:\n" + ANNOTATE_NOENDBR " movl $1, (%" _ASM_ARG1 ")\n" ASM_RET " .size int3_magic, .-int3_magic\n" @@ -724,16 +725,19 @@ extern void int3_selftest_ip(void); /* defined in asm below */ static int __init int3_exception_notify(struct notifier_block *self, unsigned long val, void *data) { + unsigned long selftest = (unsigned long)&int3_selftest_ip; struct die_args *args = data; struct pt_regs *regs = args->regs; + OPTIMIZER_HIDE_VAR(selftest); + if (!regs || user_mode(regs)) return NOTIFY_DONE; if (val != DIE_INT3) return NOTIFY_DONE; - if (regs->ip - INT3_INSN_SIZE != (unsigned long)&int3_selftest_ip) + if (regs->ip - INT3_INSN_SIZE != selftest) return NOTIFY_DONE; int3_emulate_call(regs, (unsigned long)&int3_magic); @@ -757,7 +761,9 @@ static noinline void __init int3_selftest(void) * INT3 padded with NOP to CALL_INSN_SIZE. The int3_exception_nb * notifier above will emulate CALL for us. */ - asm volatile ("int3_selftest_ip: int3; nop; nop; nop; nop\n\t" + asm volatile ("int3_selftest_ip:\n\t" + ANNOTATE_NOENDBR + " int3; nop; nop; nop; nop\n\t" : ASM_CALL_CONSTRAINT : __ASM_SEL_RAW(a, D) (&val) : "memory"); diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 9b6fa760e1df..462cc1e18919 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -99,6 +99,7 @@ SYM_CODE_END(startup_64) SYM_CODE_START(secondary_startup_64) UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR /* * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0, * and someone has loaded a mapped page table. @@ -127,6 +128,7 @@ SYM_CODE_START(secondary_startup_64) */ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR /* * Retrieve the modifier (SME encryption mask if SME is active) to be @@ -192,6 +194,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) jmp *%rax 1: UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR // above /* * We must switch to a new descriptor in kernel space for the GDT @@ -299,6 +302,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) pushq %rax # target address in negative space lretq .Lafter_lret: + ANNOTATE_NOENDBR SYM_CODE_END(secondary_startup_64) #include "verify_cpu.S" diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 9ea0e3e79896..8ef933c03afa 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1033,6 +1033,7 @@ asm( ".type __kretprobe_trampoline, @function\n" "__kretprobe_trampoline:\n" #ifdef CONFIG_X86_64 + ANNOTATE_NOENDBR /* Push a fake return address to tell the unwinder it's a kretprobe. */ " pushq $__kretprobe_trampoline\n" UNWIND_HINT_FUNC diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 5b65f6ec5ee6..c1d8626c53b6 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -42,6 +42,7 @@ .code64 SYM_CODE_START_NOALIGN(relocate_kernel) UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR /* * %rdi indirection_page * %rsi page_list @@ -223,6 +224,7 @@ SYM_CODE_END(identity_mapped) SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped) UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR // RET target, above movq RSP(%r8), %rsp movq CR4(%r8), %rax movq %rax, %cr4 |