Merge tag 'folio-5.18d' of git://git.infradead.org/users/willy/pagecache

[linux-2.6-microblaze.git] / arch / x86 / kernel / kprobes / core.c

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 6290712..7c4ab88 100644 (file)
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -52,6 +52,7 @@
 #include <asm/insn.h>
 #include <asm/debugreg.h>
 #include <asm/set_memory.h>
+#include <asm/ibt.h>
 
 #include "common.h"
 
@@ -193,17 +194,10 @@ static unsigned long
 __recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr)
 {
        struct kprobe *kp;
-       unsigned long faddr;
+       bool faddr;
 
        kp = get_kprobe((void *)addr);
-       faddr = ftrace_location(addr);
-       /*
-        * Addresses inside the ftrace location are refused by
-        * arch_check_ftrace_location(). Something went terribly wrong
-        * if such an address is checked here.
-        */
-       if (WARN_ON(faddr && faddr != addr))
-               return 0UL;
+       faddr = ftrace_location(addr) == addr;
        /*
         * Use the current code if it is not modified by Kprobe
         * and it cannot be modified by ftrace.
@@ -301,6 +295,22 @@ static int can_probe(unsigned long paddr)
        return (addr == paddr);
 }
 
+/* If x86 supports IBT (ENDBR) it must be skipped. */
+kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offset,
+                                        bool *on_func_entry)
+{
+       if (is_endbr(*(u32 *)addr)) {
+               *on_func_entry = !offset || offset == 4;
+               if (*on_func_entry)
+                       offset = 4;
+
+       } else {
+               *on_func_entry = !offset;
+       }
+
+       return (kprobe_opcode_t *)(addr + offset);
+}
+
 /*
  * Copy an instruction with recovering modified instruction by kprobes
  * and adjust the displacement if the instruction uses the %rip-relative
@@ -801,18 +811,6 @@ set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
                = (regs->flags & X86_EFLAGS_IF);
 }
 
-void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
-{
-       unsigned long *sara = stack_addr(regs);
-
-       ri->ret_addr = (kprobe_opcode_t *) *sara;
-       ri->fp = sara;
-
-       /* Replace the return addr with trampoline addr */
-       *sara = (unsigned long) &__kretprobe_trampoline;
-}
-NOKPROBE_SYMBOL(arch_prepare_kretprobe);
-
 static void kprobe_post_process(struct kprobe *cur, struct pt_regs *regs,
                               struct kprobe_ctlblk *kcb)
 {
@@ -1013,100 +1011,6 @@ int kprobe_int3_handler(struct pt_regs *regs)
 }
 NOKPROBE_SYMBOL(kprobe_int3_handler);
 
-/*
- * When a retprobed function returns, this code saves registers and
- * calls trampoline_handler() runs, which calls the kretprobe's handler.
- */
-asm(
-       ".text\n"
-       ".global __kretprobe_trampoline\n"
-       ".type __kretprobe_trampoline, @function\n"
-       "__kretprobe_trampoline:\n"
-#ifdef CONFIG_X86_64
-       /* Push a fake return address to tell the unwinder it's a kretprobe. */
-       "       pushq $__kretprobe_trampoline\n"
-       UNWIND_HINT_FUNC
-       /* Save the 'sp - 8', this will be fixed later. */
-       "       pushq %rsp\n"
-       "       pushfq\n"
-       SAVE_REGS_STRING
-       "       movq %rsp, %rdi\n"
-       "       call trampoline_handler\n"
-       RESTORE_REGS_STRING
-       /* In trampoline_handler(), 'regs->flags' is copied to 'regs->sp'. */
-       "       addq $8, %rsp\n"
-       "       popfq\n"
-#else
-       /* Push a fake return address to tell the unwinder it's a kretprobe. */
-       "       pushl $__kretprobe_trampoline\n"
-       UNWIND_HINT_FUNC
-       /* Save the 'sp - 4', this will be fixed later. */
-       "       pushl %esp\n"
-       "       pushfl\n"
-       SAVE_REGS_STRING
-       "       movl %esp, %eax\n"
-       "       call trampoline_handler\n"
-       RESTORE_REGS_STRING
-       /* In trampoline_handler(), 'regs->flags' is copied to 'regs->sp'. */
-       "       addl $4, %esp\n"
-       "       popfl\n"
-#endif
-       ASM_RET
-       ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n"
-);
-NOKPROBE_SYMBOL(__kretprobe_trampoline);
-/*
- * __kretprobe_trampoline() skips updating frame pointer. The frame pointer
- * saved in trampoline_handler() points to the real caller function's
- * frame pointer. Thus the __kretprobe_trampoline() doesn't have a
- * standard stack frame with CONFIG_FRAME_POINTER=y.
- * Let's mark it non-standard function. Anyway, FP unwinder can correctly
- * unwind without the hint.
- */
-STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline);
-
-/* This is called from kretprobe_trampoline_handler(). */
-void arch_kretprobe_fixup_return(struct pt_regs *regs,
-                                kprobe_opcode_t *correct_ret_addr)
-{
-       unsigned long *frame_pointer = &regs->sp + 1;
-
-       /* Replace fake return address with real one. */
-       *frame_pointer = (unsigned long)correct_ret_addr;
-}
-
-/*
- * Called from __kretprobe_trampoline
- */
-__used __visible void trampoline_handler(struct pt_regs *regs)
-{
-       unsigned long *frame_pointer;
-
-       /* fixup registers */
-       regs->cs = __KERNEL_CS;
-#ifdef CONFIG_X86_32
-       regs->gs = 0;
-#endif
-       regs->ip = (unsigned long)&__kretprobe_trampoline;
-       regs->orig_ax = ~0UL;
-       regs->sp += sizeof(long);
-       frame_pointer = &regs->sp + 1;
-
-       /*
-        * The return address at 'frame_pointer' is recovered by the
-        * arch_kretprobe_fixup_return() which called from the
-        * kretprobe_trampoline_handler().
-        */
-       kretprobe_trampoline_handler(regs, frame_pointer);
-
-       /*
-        * Copy FLAGS to 'pt_regs::sp' so that __kretprobe_trapmoline()
-        * can do RET right after POPF.
-        */
-       regs->sp = regs->flags;
-}
-NOKPROBE_SYMBOL(trampoline_handler);
-
 int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 {
        struct kprobe *cur = kprobe_running();