Merge tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Comprehensive interface overhaul:
   =================================

   Objtool's interface has some issues:

     - Several features are done unconditionally, without any way to
       turn them off. Some of them might be surprising. This makes
       objtool tricky to use, and prevents porting individual features
       to other arches.

     - The config dependencies are too coarse-grained. Objtool
       enablement is tied to CONFIG_STACK_VALIDATION, but it has several
       other features independent of that.

     - The objtool subcmds ("check" and "orc") are clumsy: "check" is
       really a subset of "orc", so it has all the same options.

       The subcmd model has never really worked for objtool, as it only
       has a single purpose: "do some combination of things on an object
       file".

     - The '--lto' and '--vmlinux' options are nonsensical and have
       surprising behavior.

   Overhaul the interface:

      - get rid of subcmds

      - make all features individually selectable

      - remove and/or clarify confusing/obsolete options

      - update the documentation

      - fix some bugs found along the way

 - Fix x32 regression

 - Fix Kbuild cleanup bugs

 - Add scripts/objdump-func helper script to disassemble a single
   function from an object file.

 - Rewrite scripts/faddr2line to be section-aware, by basing it on
   'readelf', moving it away from 'nm', which doesn't handle multiple
   sections well, which can result in decoding failure.

 - Rewrite & fix symbol handling - which had a number of bugs wrt.
   object files that don't have global symbols - which is rare but
   possible. Also fix a bunch of symbol handling bugs found along the
   way.

* tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  objtool: Fix objtool regression on x32 systems
  objtool: Fix symbol creation
  scripts/faddr2line: Fix overlapping text section failures
  scripts: Create objdump-func helper script
  objtool: Remove libsubcmd.a when make clean
  objtool: Remove inat-tables.c when make clean
  objtool: Update documentation
  objtool: Remove --lto and --vmlinux in favor of --link
  objtool: Add HAVE_NOINSTR_VALIDATION
  objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
  objtool: Make noinstr hacks optional
  objtool: Make jump label hack optional
  objtool: Make static call annotation optional
  objtool: Make stack validation frame-pointer-specific
  objtool: Add CONFIG_OBJTOOL
  objtool: Extricate sls from stack validation
  objtool: Rework ibt and extricate from stack validation
  objtool: Make stack validation optional
  objtool: Add option to print section addresses
  objtool: Don't print parentheses in function addresses
  ...
This commit is contained in:
Linus Torvalds
2022-05-24 10:36:38 -07:00
34 changed files with 965 additions and 693 deletions

View File

@@ -108,16 +108,22 @@ objtool_link()
local objtoolcmd;
local objtoolopt;
if is_enabled CONFIG_STACK_VALIDATION && \
( is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT ); then
if ! is_enabled CONFIG_OBJTOOL; then
return;
fi
# Don't perform vmlinux validation unless explicitly requested,
# but run objtool on vmlinux.o now that we have an object file.
if is_enabled CONFIG_UNWINDER_ORC; then
objtoolcmd="orc generate"
if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
# For LTO and IBT, objtool doesn't run on individual
# translation units. Run everything on vmlinux instead.
if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then
objtoolopt="${objtoolopt} --hacks=jump_label"
fi
objtoolopt="${objtoolopt} --lto"
if is_enabled CONFIG_HAVE_NOINSTR_HACK; then
objtoolopt="${objtoolopt} --hacks=noinstr"
fi
if is_enabled CONFIG_X86_KERNEL_IBT; then
objtoolopt="${objtoolopt} --ibt"
@@ -126,34 +132,44 @@ objtool_link()
if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then
objtoolopt="${objtoolopt} --mcount"
fi
fi
if is_enabled CONFIG_VMLINUX_VALIDATION; then
objtoolopt="${objtoolopt} --noinstr"
fi
if is_enabled CONFIG_UNWINDER_ORC; then
objtoolopt="${objtoolopt} --orc"
fi
if [ -n "${objtoolopt}" ]; then
if [ -z "${objtoolcmd}" ]; then
objtoolcmd="check"
fi
objtoolopt="${objtoolopt} --vmlinux"
if ! is_enabled CONFIG_FRAME_POINTER; then
objtoolopt="${objtoolopt} --no-fp"
fi
if is_enabled CONFIG_GCOV_KERNEL; then
objtoolopt="${objtoolopt} --no-unreachable"
fi
if is_enabled CONFIG_RETPOLINE; then
objtoolopt="${objtoolopt} --retpoline"
fi
objtoolopt="${objtoolopt} --uaccess"
if is_enabled CONFIG_SLS; then
objtoolopt="${objtoolopt} --sls"
fi
if is_enabled CONFIG_STACK_VALIDATION; then
objtoolopt="${objtoolopt} --stackval"
fi
if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then
objtoolopt="${objtoolopt} --static-call"
fi
objtoolopt="${objtoolopt} --uaccess"
fi
if is_enabled CONFIG_NOINSTR_VALIDATION; then
objtoolopt="${objtoolopt} --noinstr"
fi
if [ -n "${objtoolopt}" ]; then
if is_enabled CONFIG_GCOV_KERNEL; then
objtoolopt="${objtoolopt} --no-unreachable"
fi
objtoolopt="${objtoolopt} --link"
info OBJTOOL ${1}
tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1}
tools/objtool/objtool ${objtoolopt} ${1}
fi
}