Commit 736e80a4 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Thomas Gleixner

retpoline: Introduce start/end markers of indirect thunk

Introduce start/end markers of __x86_indirect_thunk_* functions.
To make it easy, consolidate .text.__x86.indirect_thunk.* sections
to one .text.__x86.indirect_thunk section and put it in the
end of kernel text section and adds __indirect_thunk_start/end
so that other subsystem (e.g. kprobes) can identify it.
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/151629206178.10241.6828804696410044771.stgit@devbox
parent 6f41c34d
......@@ -194,6 +194,9 @@ enum spectre_v2_mitigation {
SPECTRE_V2_IBRS,
};
extern char __indirect_thunk_start[];
extern char __indirect_thunk_end[];
/*
* On VMEXIT we must ensure that no RSB predictions learned in the guest
* can be followed in the host, by overwriting the RSB completely. Both
......
......@@ -124,6 +124,12 @@ SECTIONS
ASSERT(. - _entry_trampoline == PAGE_SIZE, "entry trampoline is too big");
#endif
#ifdef CONFIG_RETPOLINE
__indirect_thunk_start = .;
*(.text.__x86.indirect_thunk)
__indirect_thunk_end = .;
#endif
/* End of text section */
_etext = .;
} :text = 0x9090
......
......@@ -9,7 +9,7 @@
#include <asm/nospec-branch.h>
.macro THUNK reg
.section .text.__x86.indirect_thunk.\reg
.section .text.__x86.indirect_thunk
ENTRY(__x86_indirect_thunk_\reg)
CFI_STARTPROC
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment