Commit 6f8f0dc9 authored by Arvind Sankar's avatar Arvind Sankar Committed by Borislav Petkov
Browse files

x86/vmlinux: Drop unneeded linker script discard of .eh_frame 



Now that .eh_frame sections for the files in setup.elf and realmode.elf
are not generated anymore, the linker scripts don't need the special
output section name /DISCARD/ any more.

Remove the one in the main kernel linker script as well, since there are
no .eh_frame sections already, and fix up a comment referencing .eh_frame.

Update the comment in asm/dwarf2.h referring to .eh_frame so it continues
to make sense, as well as being more specific.

 [ bp: Touch up commit message. ]

Signed-off-by: default avatarArvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Tested-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200224232129.597160-3-nivedita@alum.mit.edu
parent 003602ad

arch/x86/boot/compressed/vmlinux.lds.S

+0 −5
Original line number Diff line number Diff line
@@ -73,9 +73,4 @@ SECTIONS 
#endif

	. = ALIGN(PAGE_SIZE);	/* keep ZO size page aligned */

	_end = .;



	/* Discard .eh_frame to save some space */

	/DISCARD/ : {

		*(.eh_frame)

	}

}

arch/x86/boot/setup.ld

+0 −1
Original line number Diff line number Diff line
@@ -52,7 +52,6 @@ SECTIONS 
	_end = .;



	/DISCARD/	: {

		*(.eh_frame)

		*(.note*)

	}

arch/x86/include/asm/dwarf2.h

+2 −2
Original line number Diff line number Diff line
@@ -42,8 +42,8 @@ 
	 * Emit CFI data in .debug_frame sections, not .eh_frame sections.

	 * The latter we currently just discard since we don't do DWARF

	 * unwinding at runtime.  So only the offline DWARF information is

	 * useful to anyone.  Note we should not use this directive if

	 * vmlinux.lds.S gets changed so it doesn't discard .eh_frame.

	 * useful to anyone.  Note we should not use this directive if we

	 * ever decide to enable DWARF unwinding at runtime.

	 */

	.cfi_sections .debug_frame

#else

arch/x86/kernel/vmlinux.lds.S

+2 −5
Original line number Diff line number Diff line
@@ -313,8 +313,8 @@ SECTIONS 


	. = ALIGN(8);

	/*

	 * .exit.text is discard at runtime, not link time, to deal with

	 *  references from .altinstructions and .eh_frame

	 * .exit.text is discarded at runtime, not link time, to deal with

	 *  references from .altinstructions

	 */

	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {

		EXIT_TEXT
@@ -412,9 +412,6 @@ SECTIONS 
	DWARF_DEBUG



	DISCARDS

	/DISCARD/ : {

		*(.eh_frame)

	}

}

arch/x86/realmode/rm/realmode.lds.S

+0 −1
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ SECTIONS 
	/DISCARD/ : {

		*(.note*)

		*(.debug*)

		*(.eh_frame*)

	}



#include "pasyms.h"