uprobes/x86: Kill adjust_ret_addr(), simplify UPROBE_FIX_CALL logic

The only insn which could have both UPROBE_FIX_IP and UPROBE_FIX_CALL
was 0xe8 "call relative", and now it is handled by branch_xol_ops.

So we can change default_post_xol_op(UPROBE_FIX_CALL) to simply push
the address of next insn == utask->vaddr + insn.length, just we need
to record insn.length into the new auprobe->def.ilen member.

Note: if/when we teach branch_xol_ops to support jcxz/loopz we can
remove the "correction" logic, UPROBE_FIX_IP can use the same address.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
index 9ce25ce04fee..a040d493a4f9 100644
--- a/arch/x86/include/asm/uprobes.h
+++ b/arch/x86/include/asm/uprobes.h
@@ -54,6 +54,7 @@ struct arch_uprobe {
 			long	riprel_target;
 #endif
 			u8	fixups;
+			u8	ilen;
 		} 			def;
 	};
 };