From nobody Tue Dec 16 14:34:15 2025 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA80A223DE8 for ; Thu, 8 May 2025 11:43:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746704626; cv=none; b=mr511cWI5UceGbjJryhoA3eZJZi/IS67SY/4UqchLnuG9w4+K23Bl54XVZ+Jw7HPXdd18ZDdeHTNPppyZdCYovW2BXystNRlysUCuPDh5umMeGWs6fkiTamU8Qx4sRCr8XYC/nv5JyvI5EJgOAZlhbk+Axj8cmPvLCjC6E3yaDY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746704626; c=relaxed/simple; bh=SNkN+aUxCD4khnvAOEVbcOq4dfyvknF/k2ubANz9rSs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=nrAh88sdCOBmWDh89/gz1vnDQ/BpY/T9fPQ346YQwPOE/2nP4bIyG66k1SEUlL3MwNjlbM+PJlmSVOdUpomwvbkVkCAZh0yWlFbnwdRb4qzZhD6GOSKLYmttCMpGYf8hfBwR9jPTjMCHRsMeJZmr02hc6bmvnWA3v1FW0ODVApo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=CNxOF+cA; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CNxOF+cA" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-442cdf07ad9so3801825e9.2 for ; Thu, 08 May 2025 04:43:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746704623; x=1747309423; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=OFL6LCOiCuB4AhqO2WO2qSyMds3tZvVGSAG8TlD6fm8=; b=CNxOF+cAogGpctO7kcy9I3N0R+jWF6U8jYDByBmz1gkJpVONf/DWaiZ1WK0wBMOmzx G8/vZeIQPx7FNuj65Wrmr4/8gNyQ5kt33+fLjtOTvCS8GoSKJbrcMBQe77CmthBt8ajS IEXpK5IaqFN8dtgmKszkDrW9S7mPXorwlpEWsGO0Nn4U89d3iitgojSeq09Rga+MYqzV GRcuEtY8a+4JZg9NNYfhm3ktXUiHzV4Ll6gOmR50Zl53+7IDaz7Bh1yVZQ2q0ktc/tYP t1dDdxeWyQ4q9NRed08kqGMs8erR7TQSGWXDRumgJvts4h31SOHGR14sIJpq3vt3vS+O v+Eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746704623; x=1747309423; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=OFL6LCOiCuB4AhqO2WO2qSyMds3tZvVGSAG8TlD6fm8=; b=jlOOgbIlfwWlmmfDzhrshcvUyLAlwqT2rRWigzJhrikZOBtbCMXXIZ1IupRxwkUUNg vspDPlXipvJeYHduWWg33kgPDkMnv3c9EPLrbZ3A47oBlG5ua4QZtkJ+Jr2euCD60+WU ya9vVX9pTub/8GAeClFSSycGZPIZZhStqNBirRLtuClM/1o6N3iLqm2Wuo1brXSuZaNA ih9a7cfqrxjEzg4zbqJ4fn7zlZHgo2smc3IX98MoxALn8NV9pPYea2Q4i8BtyxOGGxXv 2wx6OZTx/iZtEq910sUlHsk8TPOc9SdTq8fW24HdkPLv3LFLLmzgoP7NXSZvKiKBVfsL JDOg== X-Gm-Message-State: AOJu0YxOWitr0HsrJ48vlyM+ICvmq+iQLSRCiS83gUqsHz/zDkY440nk 7wBlvuZxwR31WwlZ6JnluS7/LgDVUCkzjipsDpNwV3Dni3iMgdsVKUVkX1K+nULm+Ifryg== X-Google-Smtp-Source: AGHT+IHhgjjPcSzSlIvKKbGxCHF4/xh5ayQlKt49bS4/7hxPqwU88888d3Bex6M06x7UUFIZSSVblKdy X-Received: from wmbem23.prod.google.com ([2002:a05:600c:8217:b0:441:b661:2d94]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3d13:b0:43c:f3e4:d6f6 with SMTP id 5b1f17b1804b1-441d44e3660mr72820155e9.31.1746704623167; Thu, 08 May 2025 04:43:43 -0700 (PDT) Date: Thu, 8 May 2025 13:43:32 +0200 In-Reply-To: <20250508114328.2460610-5-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250508114328.2460610-5-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=4218; i=ardb@kernel.org; h=from:subject; bh=j8k/j5lLwOtOO5g2RunsS1a0UPrHZPgoaoPHRVCj0HU=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIUNmxtNDLXyH4vbP5Hn2N3xteLLlH9mFD+alrm7kKly3W eLd4e+rO0pZGMQ4GGTFFFkEZv99t/P0RKla51myMHNYmUCGMHBxCsBEbi9lZGh+6vuo8tplgY66 2R3/RSr/Fy7eV5byx/cO7yFOxgb98iWMDHdPm57KuGFZE86venruP3lRDoPFOk/SGjfantBpO/x /FxcA X-Mailer: git-send-email 2.49.0.987.g0cc8ee98dc-goog Message-ID: <20250508114328.2460610-8-ardb+git@google.com> Subject: [PATCH v2 3/3] arm64/boot: Disallow BSS exports to startup code From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, Ard Biesheuvel , Yeoreum Yun Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Ard Biesheuvel BSS might be uninitialized when entering the startup code, so forbid the use by the startup code of any variables that live after __bss_start in the linker map. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/image-vars.h | 62 +++++++++++--------- arch/arm64/kernel/vmlinux.lds.S | 2 + 2 files changed, 35 insertions(+), 29 deletions(-) diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index c3b4c0479d5c..a928e0c0b45a 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -10,6 +10,12 @@ #error This file should only be included in vmlinux.lds.S #endif =20 +#define PI_EXPORT_SYM(sym) \ + __PI_EXPORT_SYM(sym, __pi_ ## sym, Cannot export BSS symbol sym to startu= p code) +#define __PI_EXPORT_SYM(sym, pisym, msg)\ + PROVIDE(pisym =3D sym); \ + ASSERT((sym - KIMAGE_VADDR) < (__bss_start - KIMAGE_VADDR), #msg) + PROVIDE(__efistub_primary_entry =3D primary_entry); =20 /* @@ -36,37 +42,35 @@ PROVIDE(__pi___memcpy =3D __pi_memcpy); PROVIDE(__pi___memmove =3D __pi_memmove); PROVIDE(__pi___memset =3D __pi_memset); =20 -PROVIDE(__pi_id_aa64isar1_override =3D id_aa64isar1_override); -PROVIDE(__pi_id_aa64isar2_override =3D id_aa64isar2_override); -PROVIDE(__pi_id_aa64mmfr0_override =3D id_aa64mmfr0_override); -PROVIDE(__pi_id_aa64mmfr1_override =3D id_aa64mmfr1_override); -PROVIDE(__pi_id_aa64mmfr2_override =3D id_aa64mmfr2_override); -PROVIDE(__pi_id_aa64pfr0_override =3D id_aa64pfr0_override); -PROVIDE(__pi_id_aa64pfr1_override =3D id_aa64pfr1_override); -PROVIDE(__pi_id_aa64smfr0_override =3D id_aa64smfr0_override); -PROVIDE(__pi_id_aa64zfr0_override =3D id_aa64zfr0_override); -PROVIDE(__pi_arm64_sw_feature_override =3D arm64_sw_feature_override); -PROVIDE(__pi_arm64_use_ng_mappings =3D arm64_use_ng_mappings); +PI_EXPORT_SYM(id_aa64isar1_override); +PI_EXPORT_SYM(id_aa64isar2_override); +PI_EXPORT_SYM(id_aa64mmfr0_override); +PI_EXPORT_SYM(id_aa64mmfr1_override); +PI_EXPORT_SYM(id_aa64mmfr2_override); +PI_EXPORT_SYM(id_aa64pfr0_override); +PI_EXPORT_SYM(id_aa64pfr1_override); +PI_EXPORT_SYM(id_aa64smfr0_override); +PI_EXPORT_SYM(id_aa64zfr0_override); +PI_EXPORT_SYM(arm64_sw_feature_override); +PI_EXPORT_SYM(arm64_use_ng_mappings); #ifdef CONFIG_CAVIUM_ERRATUM_27456 -PROVIDE(__pi_cavium_erratum_27456_cpus =3D cavium_erratum_27456_cpus); -PROVIDE(__pi_is_midr_in_range_list =3D is_midr_in_range_list); +PI_EXPORT_SYM(cavium_erratum_27456_cpus); +PI_EXPORT_SYM(is_midr_in_range_list); #endif -PROVIDE(__pi__ctype =3D _ctype); -PROVIDE(__pi_memstart_offset_seed =3D memstart_offset_seed); - -PROVIDE(__pi_swapper_pg_dir =3D swapper_pg_dir); - -PROVIDE(__pi__text =3D _text); -PROVIDE(__pi__stext =3D _stext); -PROVIDE(__pi__etext =3D _etext); -PROVIDE(__pi___start_rodata =3D __start_rodata); -PROVIDE(__pi___inittext_begin =3D __inittext_begin); -PROVIDE(__pi___inittext_end =3D __inittext_end); -PROVIDE(__pi___initdata_begin =3D __initdata_begin); -PROVIDE(__pi___initdata_end =3D __initdata_end); -PROVIDE(__pi__data =3D _data); -PROVIDE(__pi___bss_start =3D __bss_start); -PROVIDE(__pi__end =3D _end); +PI_EXPORT_SYM(_ctype); +PI_EXPORT_SYM(memstart_offset_seed); + +PI_EXPORT_SYM(swapper_pg_dir); + +PI_EXPORT_SYM(_text); +PI_EXPORT_SYM(_stext); +PI_EXPORT_SYM(_etext); +PI_EXPORT_SYM(__start_rodata); +PI_EXPORT_SYM(__inittext_begin); +PI_EXPORT_SYM(__inittext_end); +PI_EXPORT_SYM(__initdata_begin); +PI_EXPORT_SYM(__initdata_end); +PI_EXPORT_SYM(_data); =20 #ifdef CONFIG_KVM =20 diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.ld= s.S index 466544c47dca..e4a525a865c1 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -319,6 +319,7 @@ SECTIONS =20 /* start of zero-init region */ BSS_SECTION(SBSS_ALIGN, 0, 0) + __pi___bss_start =3D __bss_start; =20 . =3D ALIGN(PAGE_SIZE); __pi_init_pg_dir =3D .; @@ -332,6 +333,7 @@ SECTIONS . =3D ALIGN(SEGMENT_ALIGN); __pecoff_data_size =3D ABSOLUTE(. - __initdata_begin); _end =3D .; + __pi__end =3D .; =20 STABS_DEBUG DWARF_DEBUG --=20 2.49.0.987.g0cc8ee98dc-goog