linux.git/scripts/Makefile.vmlinux_o, branch v6.6.132 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git x86/srso: Fix unret validation dependencies 2023-11-20T10:58:52+00:00 Josh Poimboeuf jpoimboe@kernel.org 2023-09-05T05:04:53+00:00 626ea25e6d1d416d4b85f583e2dbcd6ebc48f081 [ Upstream commit eeb9f34df065f42f0c9195b322ba6df420c9fc92 ] CONFIG_CPU_SRSO isn't dependent on CONFIG_CPU_UNRET_ENTRY (AMD Retbleed), so the two features are independently configurable. Fix several issues for the (presumably rare) case where CONFIG_CPU_SRSO is enabled but CONFIG_CPU_UNRET_ENTRY isn't. Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/299fb7740174d0f2335e91c58af0e9c242b4bac1.1693889988.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit eeb9f34df065f42f0c9195b322ba6df420c9fc92 ]

CONFIG_CPU_SRSO isn't dependent on CONFIG_CPU_UNRET_ENTRY (AMD
Retbleed), so the two features are independently configurable.  Fix
several issues for the (presumably rare) case where CONFIG_CPU_SRSO is
enabled but CONFIG_CPU_UNRET_ENTRY isn't.

Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/299fb7740174d0f2335e91c58af0e9c242b4bac1.1693889988.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o 2022-10-02T18:52:58+00:00 Masahiro Yamada masahiroy@kernel.org 2022-09-28T06:39:40+00:00 7a342e6c7735e13b294374cb0a0f6283d8667496 Do not build modules.builtin(.modinfo) as a side-effect of vmlinux. There are no good reason to rebuild them just because any of vmlinux's prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> 
Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.

There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
kbuild: use obj-y instead extra-y for objects placed at the head 2022-10-02T09:04:05+00:00 Masahiro Yamada masahiroy@kernel.org 2022-09-24T18:19:14+00:00 3216484550610470013b7ce1c9ed272da0a74589 The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> 
The objects placed at the head of vmlinux need special treatments:

 - arch/$(SRCARCH)/Makefile adds them to head-y in order to place
   them before other archives in the linker command line.

 - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
   obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
kbuild: use objtool-args-y to clean up objtool arguments 2022-09-28T19:40:15+00:00 Masahiro Yamada masahiroy@kernel.org 2022-09-06T18:49:35+00:00 9ec6ab6ee5ca72afdf8f60c330ad997825c0819b Based on Linus' patch. Refactor scripts/Makefile.vmlinux_o as well. Link: https://lore.kernel.org/lkml/CAHk-=wgjTMQgiKzBZTmb=uWGDEQxDdyF1+qxBkODYciuNsmwnw@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> 
Based on Linus' patch. Refactor scripts/Makefile.vmlinux_o as well.

Link: https://lore.kernel.org/lkml/CAHk-=wgjTMQgiKzBZTmb=uWGDEQxDdyF1+qxBkODYciuNsmwnw@mail.gmail.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
x86/retbleed: Add fine grained Kconfig knobs 2022-06-29T15:43:41+00:00 Peter Zijlstra peterz@infradead.org 2022-06-27T22:21:17+00:00 f43b9876e857c739d407bc56df288b0ebe1a9164 Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> 
Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
objtool: Add entry UNRET validation 2022-06-27T08:34:00+00:00 Peter Zijlstra peterz@infradead.org 2022-06-14T21:16:03+00:00 a09a6e2399ba0595c3042b3164f3ca68a3cff33e Since entry asm is tricky, add a validation pass that ensures the retbleed mitigation has been done before the first actual RET instruction. Entry points are those that either have UNWIND_HINT_ENTRY, which acts as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or those that have UWIND_HINT_IRET_REGS at +0. This is basically a variant of validate_branch() that is intra-function and it will simply follow all branches from marked entry points and ensures that all paths lead to ANNOTATE_UNRET_END. If a path hits RET or an indirection the path is a fail and will be reported. There are 3 ANNOTATE_UNRET_END instances: - UNTRAIN_RET itself - exception from-kernel; this path doesn't need UNTRAIN_RET - all early exceptions; these also don't need UNTRAIN_RET Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> 
Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done before the first actual RET
instruction.

Entry points are those that either have UNWIND_HINT_ENTRY, which acts
as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or
those that have UWIND_HINT_IRET_REGS at +0.

This is basically a variant of validate_branch() that is
intra-function and it will simply follow all branches from marked
entry points and ensures that all paths lead to ANNOTATE_UNRET_END.

If a path hits RET or an indirection the path is a fail and will be
reported.

There are 3 ANNOTATE_UNRET_END instances:

 - UNTRAIN_RET itself
 - exception from-kernel; this path doesn't need UNTRAIN_RET
 - all early exceptions; these also don't need UNTRAIN_RET

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
kbuild: factor out the common objtool arguments 2022-06-04T21:20:57+00:00 Masahiro Yamada masahiroy@kernel.org 2022-05-28T15:47:04+00:00 b42d2306502419688190aa6dd4dab4a6def24b3d scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups for the objtool arguments. It was difficult to factor out them because all the vmlinux build rules were written in a shell script. It is somewhat tedious to touch the two files every time a new objtool option is supported. To reduce the code duplication, move the objtool for vmlinux.o into scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib so they are shared between Makefile.build and Makefile.vmlinux_o. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64) 
scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups
for the objtool arguments.

It was difficult to factor out them because all the vmlinux build rules
were written in a shell script. It is somewhat tedious to touch the two
files every time a new objtool option is supported.

To reduce the code duplication, move the objtool for vmlinux.o into
scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib
so they are shared between Makefile.build and Makefile.vmlinux_o.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o 2022-06-04T21:20:57+00:00 Masahiro Yamada masahiroy@kernel.org 2022-05-28T15:47:03+00:00 5d45950dfbb1540bba3e3762a3497de8b4a715d3 This is a preparation for moving the objtool rule in the next commit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64) 
This is a preparation for moving the objtool rule in the next commit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)