From 846d3cb171327c125d97a21daabe51b8097a1279 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 1 Mar 2023 19:06:59 -0700 Subject: [PATCH] x86, vmlinux.lds: Add RUNTIME_DISCARD_EXIT to generic DISCARDS commit aab2867d7f88f537bbaa9e59551377918631abeb upstream. In the x86 kernel, .exit.text and .exit.data sections are discarded at runtime, not by the linker. Add RUNTIME_DISCARD_EXIT to generic DISCARDS and define it in the x86 kernel linker script to keep them. The sections are added before the DISCARD directive so document here only the situation explicitly as this change doesn't have any effect on the generated kernel. Also, other architectures like ARM64 will use it too so generalize the approach with the RUNTIME_DISCARD_EXIT define. [ bp: Massage and extend commit message. ] Signed-off-by: H.J. Lu Signed-off-by: Borislav Petkov Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20200326193021.255002-1-hjl.tools@gmail.com Signed-off-by: Tom Saeger --- arch/x86/kernel/vmlinux.lds.S | 2 ++ include/asm-generic/vmlinux.lds.h | 11 +++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 1afe211d7a7ca..7e0e21082c93e 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -21,6 +21,8 @@ #define LOAD_OFFSET __START_KERNEL_map #endif +#define RUNTIME_DISCARD_EXIT + #include #include #include diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c3bcac22c3894..2d45d98773e23 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -900,10 +900,17 @@ * section definitions so that such archs put those in earlier section * definitions. */ +#ifdef RUNTIME_DISCARD_EXIT +#define EXIT_DISCARDS +#else +#define EXIT_DISCARDS \ + EXIT_TEXT \ + EXIT_DATA +#endif + #define DISCARDS \ /DISCARD/ : { \ - EXIT_TEXT \ - EXIT_DATA \ + EXIT_DISCARDS \ EXIT_CALL \ *(.discard) \ *(.discard.*) \ -- 2.39.5