linux/tools/objtool
Allan Xavier 4a60aa05a0 objtool: Support per-function rodata sections
Add support for processing switch jump tables in objects with multiple
.rodata sections, such as those created by '-ffunction-sections' and
'-fdata-sections'.  Currently, objtool always looks in .rodata for jump
table information, which results in many "sibling call from callable
instruction with modified stack frame" warnings with objects compiled
using those flags.

The fix is comprised of three parts:

1. Flagging all .rodata sections when importing ELF information for
   easier checking later.

2. Keeping a reference to the section each relocation is from in order
   to get the list_head for the other relocations in that section.

3. Finding jump tables by following relocations to .rodata sections,
   rather than always referencing a single global .rodata section.

The patch has been tested without data sections enabled and no
differences in the resulting orc unwind information were seen.

Note that as objtool adds terminators to end of each .text section the
unwind information generated between a function+data sections build and
a normal build aren't directly comparable. Manual inspection suggests
that objtool is now generating the correct information, or at least
making more of an effort to do so than it did previously.

Signed-off-by: Allan Xavier <allan.x.xavier@oracle.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/099bdc375195c490dda04db777ee0b95d566ded1.1536325914.git.jpoimboe@redhat.com
2018-09-08 12:33:01 +02:00
..
arch/x86 x86/unwind/orc: Detect the end of the stack 2018-06-21 16:34:56 +02:00
Documentation x86/asm: Fix inline asm call constraints for Clang 2017-09-23 15:06:20 +02:00
.gitignore objtool: Move synced files to their original relative locations 2017-11-07 10:48:23 +01:00
arch.h objtool: Assume unannotated UD2 instructions are dead ends 2017-07-28 08:33:32 +02:00
Build objtool: Add ORC unwind table generation 2017-07-18 10:57:43 +02:00
builtin-check.c objtool: Add module specific retpoline rules 2018-02-21 09:05:05 +01:00
builtin-orc.c objtool: Use existing global variables for options 2018-02-21 09:05:04 +01:00
builtin.h objtool: Add module specific retpoline rules 2018-02-21 09:05:05 +01:00
cfi.h objtool: Handle GCC stack pointer adjustment bug 2017-08-30 10:48:41 +02:00
check.c objtool: Support per-function rodata sections 2018-09-08 12:33:01 +02:00
check.h objtool: Support per-function rodata sections 2018-09-08 12:33:01 +02:00
elf.c objtool: Support per-function rodata sections 2018-09-08 12:33:01 +02:00
elf.h objtool: Support per-function rodata sections 2018-09-08 12:33:01 +02:00
Makefile kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS 2018-07-18 01:18:05 +09:00
objtool.c objtool: Print top level commands on incorrect usage 2017-10-18 15:22:26 +02:00
orc_dump.c x86/unwind/orc: Detect the end of the stack 2018-06-21 16:34:56 +02:00
orc_gen.c x86/unwind/orc: Detect the end of the stack 2018-06-21 16:34:56 +02:00
orc.h objtool: Move synced files to their original relative locations 2017-11-07 10:48:23 +01:00
special.c objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00
special.h objtool: Add tool to perform compile-time stack metadata validation 2016-02-29 08:35:12 +01:00
sync-check.sh objtool: Move kernel headers/code sync check to a script 2017-11-07 10:48:34 +01:00
warn.h objtool: Implement stack validation 2.0 2017-06-30 10:19:19 +02:00