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Commit 2ae1f49a authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

uprobes/x86: Add is_64bit_mm(), kill validate_insn_bits() 



1. Extract the ->ia32_compat check from 64bit validate_insn_bits()
   into the new helper, is_64bit_mm(), it will have more users.

   TODO: this checks is actually wrong if mm owner is X32 task,
   we need another fix which changes set_personality_ia32().

   TODO: even worse, the whole 64-or-32-bit logic is very broken
   and the fix is not simple, we need the nontrivial changes in
   the core uprobes code.

2. Kill validate_insn_bits() and change its single caller to use
   uprobe_init_insn(is_64bit_mm(mm).

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Reviewed-by: default avatarJim Keniston <jkenisto@us.ibm.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
parent 73175d0d

arch/x86/kernel/uprobes.c

+9 −11
Original line number Diff line number Diff line
@@ -231,6 +231,11 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool 
}



#ifdef CONFIG_X86_64

static inline bool is_64bit_mm(struct mm_struct *mm)

{

	return	!config_enabled(CONFIG_IA32_EMULATION) ||

		!mm->context.ia32_compat;

}

/*

 * If arch_uprobe->insn doesn't use rip-relative addressing, return

 * immediately.  Otherwise, rewrite the instruction so that it accesses
@@ -355,13 +360,11 @@ handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long * 
			*correction += 4;

	}

}



static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)

#else /* 32-bit: */

static inline bool is_64bit_mm(struct mm_struct *mm)

{

	bool x86_64 = !mm->context.ia32_compat;

	return uprobe_init_insn(auprobe, insn, x86_64);

	return false;

}

#else /* 32-bit: */

/*

 * No RIP-relative addressing on 32-bit

 */
@@ -376,11 +379,6 @@ static void handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs * 
					long *correction)

{

}



static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm,  struct insn *insn)

{

	return uprobe_init_insn(auprobe, insn, false);

}

#endif /* CONFIG_X86_64 */



struct uprobe_xol_ops {
@@ -625,7 +623,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, 
	bool fix_ip = true, fix_call = false;

	int ret;



	ret = validate_insn_bits(auprobe, mm, &insn);

	ret = uprobe_init_insn(auprobe, &insn, is_64bit_mm(mm));

	if (ret)

		return ret;