From nobody Tue Feb 10 22:15:49 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A31D728134C; Tue, 22 Apr 2025 18:35:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745346931; cv=none; b=iYJTGilWBjG5fcNn4INAJ1EuyJW08lLP75+7IK93p92rGfCkHyjSqOPlc3z9fi0fE6lVevBB8xp57AP7DbvBsgM2n5bXRzJ9Taw0iw4JfKEUG8Th5yk1o9PDvOcwnMCTRzaql5vsKCR95a+VdwZfhhseo9asMsImYmgl9PaMLS0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745346931; c=relaxed/simple; bh=0Bb/tQprLXZHVSifz2vrARZ2q/lox2IgCNaDFpKyfF0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=oxlp26fk7Swcsu5Xt6MmtZW4h8WweTerWWE2erZ4IjjutUfwelzxhlXOWver8m6rgl+bT+qfkq79PQT8MSkqws72u+DxvUlI5Whmv/0m5h5t5T27vpaj+uszPsbHmypVSMw9b2qmNkAODkSaLIdgtczdTgohydO5e13IbDzIHkw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BC1EC4CEF9; Tue, 22 Apr 2025 18:35:31 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1u7IUk-0000000Fw8P-2Kdc; Tue, 22 Apr 2025 14:37:22 -0400 Message-ID: <20250422183722.404841398@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 22 Apr 2025 14:34:42 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Josh Poimboeuf , Jens Remus , x86@kernel.org, Peter Zijlstra , Ingo Molnar , Indu Bhagat , Andy Lutomirski , Thomas Gleixner , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH v5 3/6] x86/asm: Fix VDSO DWARF generation with kernel IBT enabled References: <20250422183439.895236512@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Josh Poimboeuf The DWARF .cfi_startproc annotation needs to be at the very beginning of a function. But with kernel IBT that doesn't happen as ENDBR is sneakily embedded in SYM_FUNC_START. As a result the DWARF unwinding info is wrong at the beginning of all the VDSO functions. Fix it by adding CFI_STARTPROC and CFI_ENDPROC to SYM_FUNC_START_* and SYM_FUNC_END respectively. Note this only affects VDSO, as the CFI_* macros are empty for the kernel proper. Fixes: c4691712b546 ("x86/linkage: Add ENDBR to SYM_FUNC_START*()") Signed-off-by: Josh Poimboeuf [ Fixed rebased issues. May need extra review ] Signed-off-by: Steven Rostedt (Google) --- Changes since v4: https://lore.kernel.org/all/5c7992c111adee94e242fbca2b3e6= 4ab8e96e595.1737511963.git.jpoimboe@kernel.org/ - Rebased to latest kernel which had changes to the ENDBR caused by: 582077c94052 ("x86/cfi: Clean up linkage") arch/x86/entry/vdso/vdso-layout.lds.S | 2 +- arch/x86/entry/vdso/vgetrandom-chacha.S | 2 -- arch/x86/entry/vdso/vsgx.S | 4 --- arch/x86/include/asm/linkage.h | 33 ++++++++++++++++++++----- arch/x86/include/asm/vdso.h | 1 - 5 files changed, 28 insertions(+), 14 deletions(-) diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vd= so-layout.lds.S index ec1ac191a057..60747905de2b 100644 --- a/arch/x86/entry/vdso/vdso-layout.lds.S +++ b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -1,5 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#include +#include #include #include =20 diff --git a/arch/x86/entry/vdso/vgetrandom-chacha.S b/arch/x86/entry/vdso/= vgetrandom-chacha.S index cc82da9216fb..a33212594731 100644 --- a/arch/x86/entry/vdso/vgetrandom-chacha.S +++ b/arch/x86/entry/vdso/vgetrandom-chacha.S @@ -22,7 +22,6 @@ CONSTANTS: .octa 0x6b20657479622d323320646e61707865 * rcx: number of 64-byte blocks to write to output */ SYM_FUNC_START(__arch_chacha20_blocks_nostack) - CFI_STARTPROC .set output, %rdi .set key, %rsi .set counter, %rdx @@ -175,5 +174,4 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack) pxor temp,temp =20 ret - CFI_ENDPROC SYM_FUNC_END(__arch_chacha20_blocks_nostack) diff --git a/arch/x86/entry/vdso/vsgx.S b/arch/x86/entry/vdso/vsgx.S index 37a3d4c02366..c0342238c976 100644 --- a/arch/x86/entry/vdso/vsgx.S +++ b/arch/x86/entry/vdso/vsgx.S @@ -24,8 +24,6 @@ .section .text, "ax" =20 SYM_FUNC_START(__vdso_sgx_enter_enclave) - /* Prolog */ - .cfi_startproc push %rbp .cfi_adjust_cfa_offset 8 .cfi_rel_offset %rbp, 0 @@ -143,8 +141,6 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave) jle .Lout jmp .Lenter_enclave =20 - .cfi_endproc - _ASM_VDSO_EXTABLE_HANDLE(.Lenclu_eenter_eresume, .Lhandle_exception) =20 SYM_FUNC_END(__vdso_sgx_enter_enclave) diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h index b51d8a4673f5..1ba1f208414f 100644 --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -40,6 +40,10 @@ =20 #ifdef __ASSEMBLER__ =20 +#ifndef LINKER_SCRIPT +#include +#endif + #if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && != defined(BUILD_VDSO) #define RET jmp __x86_return_thunk #else /* CONFIG_MITIGATION_RETPOLINE */ @@ -112,34 +116,51 @@ # define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS #endif =20 +#define __SYM_FUNC_START \ + CFI_STARTPROC ASM_NL + +#define __SYM_FUNC_END \ + CFI_ENDPROC ASM_NL + /* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type = */ #define SYM_TYPED_FUNC_START(name) \ SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \ + __SYM_FUNC_START \ ENDBR =20 /* SYM_FUNC_START -- use for global functions */ #define SYM_FUNC_START(name) \ - SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) + SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \ + __SYM_FUNC_START =20 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ #define SYM_FUNC_START_NOALIGN(name) \ - SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \ + __SYM_FUNC_START =20 /* SYM_FUNC_START_LOCAL -- use for local functions */ #define SYM_FUNC_START_LOCAL(name) \ - SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) + SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) \ + __SYM_FUNC_START =20 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment = */ #define SYM_FUNC_START_LOCAL_NOALIGN(name) \ - SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \ + __SYM_FUNC_START =20 /* SYM_FUNC_START_WEAK -- use for weak functions */ #define SYM_FUNC_START_WEAK(name) \ - SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) + SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) \ + __SYM_FUNC_START =20 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ #define SYM_FUNC_START_WEAK_NOALIGN(name) \ - SYM_START(name, SYM_L_WEAK, SYM_A_NONE) + SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \ + __SYM_FUNC_START + +#define SYM_FUNC_END(name) \ + __SYM_FUNC_END \ + SYM_END(name, SYM_T_FUNC) =20 #endif /* _ASM_X86_LINKAGE_H */ =20 diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index b7253ef3205a..c4290dadba66 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -2,7 +2,6 @@ #ifndef _ASM_X86_VDSO_H #define _ASM_X86_VDSO_H =20 -#include #include #include =20 --=20 2.47.2