Message-ID: <20260211141357.271402-1-jremus@linux.ibm.com>
Date: Wed, 11 Feb 2026 15:13:51 +0100
From: Jens Remus <jremus@...ux.ibm.com>
To: linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
        bpf@...r.kernel.org, x86@...nel.org, linux-mm@...ck.org,
        Steven Rostedt <rostedt@...nel.org>
Cc: Jens Remus <jremus@...ux.ibm.com>, Josh Poimboeuf <jpoimboe@...nel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andrii Nakryiko <andrii@...nel.org>,
        Indu Bhagat <indu.bhagat@...cle.com>,
        "Jose E. Marchesi" <jemarch@....org>,
        Beau Belgrave <beaub@...ux.microsoft.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Florian Weimer <fweimer@...hat.com>, Kees Cook <kees@...nel.org>,
        "Carlos O'Donell" <codonell@...hat.com>, Sam James <sam@...too.org>,
        Dylan Hatch <dylanbhatch@...gle.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        David Hildenbrand <david@...nel.org>, "H. Peter Anvin" <hpa@...or.com>,
        "Liam R. Howlett" <Liam.Howlett@...cle.com>,
        Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
        Michal Hocko <mhocko@...e.com>, Mike Rapoport <rppt@...nel.org>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>, Heiko Carstens <hca@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>
Subject: [PATCH v9 0/6] x86/vdso: VDSO updates and fixes for sframes


This enables generation of SFrame V3 stack trace information for VDSO on
x86-64.  It's a continuation of Josh's and Steve's work:

   https://lore.kernel.org/all/cover.1737511963.git.jpoimboe@kernel.org/
   https://lore.kernel.org/all/20250425023750.669174660@goodmis.org/

This series focuses only on the VDSO code. They are helpful fixes
and updates that doesn't rely on sframes (although the last patch
is sframe related).

This series applies on top of tip:x86/entry:

  git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git  x86/entry

Like the unwind user sframe series [1] it depends on the binutils 2.46
release to be used to build the VDSO with SFrame V3 stack trace
information (using the assembler option --gsframe-3).

[1]: [PATCH v13 00/18] unwind_deferred: Implement sframe handling,
    https://lore.kernel.org/all/20260127150554.2760964-1-jremus@linux.ibm.com/

Changes in v9 (see indivicual patch notes):
- Always define KEEP_SFRAME to either true/false in specific VDSO linker
  scripts and use #if instead of #ifdef in common one. (Peter)
- Reword patch 6 commit message to provide more details.
- Note: Binutils 2.46 with SFrame V3 support has been released.

Changes in v8:
- Discard .sframe for x32 and x86-32 VDSOs. (Josh/Indu)
- Define CFI_SIGNAL_FRAME for !BUILD_VDSO.
- Drop .cfi_sections .sframe in dwarf2.h in favor of the explicitly
  specified more specific assembler option --gsframe-3.
- Incorporate missing changes and review feedback from Steven's v6
  (I erroneously based my v6 on Steven's v5):
  - Reword patch 3 commit subject to Steven's v6 one.
  - Remove SYM_F_ALIGN in __vdso_sgx_enter_enclave(). (Josh)

Changes in v7:
- Rebase on H. Peter Anvin's vDSO changes on tip:x86/entry. (Peter)
- Simplify adding assembler option -Wa,--gsframe-3.  Add for vdso64
  only.
- Align to .eh_frame and mark .sframe as KEEP in vDSO linker script.
  Note that GNU linker 2.46 will mark .sframe as KEEP in its default
  linker script as well.

Changes in v6:
- SFrame V3 support (SFrame V2 is not supported).
- Prevent GNU_SFRAME program table entry to empty .sframe section.
- Integrate v5 review feedback. (Josh)

Regards,
Jens


Josh Poimboeuf (6):
  x86/vdso: Fix DWARF generation for getrandom()
  x86/asm: Avoid emitting DWARF CFI for non-VDSO
  x86/asm: Use CFI_* macros in SYM_FUNC_* macros so they can be added to
    VDSO
  x86/vdso: Use SYM_FUNC_{START,END} in __kernel_vsyscall()
  x86/vdso: Use CFI macros in __vdso_sgx_enter_enclave()
  x86/vdso: Enable sframe generation in VDSO

 arch/Kconfig                                  |  7 +++
 arch/x86/entry/vdso/common/vdso-layout.lds.S  | 17 +++++-
 arch/x86/entry/vdso/vdso32/system_call.S      | 10 +---
 arch/x86/entry/vdso/vdso32/vdso32.lds.S       |  3 ++
 arch/x86/entry/vdso/vdso64/Makefile           |  1 +
 arch/x86/entry/vdso/vdso64/vdso64.lds.S       |  2 +
 arch/x86/entry/vdso/vdso64/vdsox32.lds.S      |  6 +++
 .../x86/entry/vdso/vdso64/vgetrandom-chacha.S |  3 +-
 arch/x86/entry/vdso/vdso64/vsgx.S             | 18 +++----
 arch/x86/include/asm/dwarf2.h                 | 52 +++++++++++++------
 arch/x86/include/asm/linkage.h                | 33 +++++++++---
 arch/x86/include/asm/vdso.h                   |  1 -
 12 files changed, 107 insertions(+), 46 deletions(-)

-- 
2.51.0

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