From nobody Tue Sep 29 09:09:31 2026 Received: from outbound.mr.icloud.com (mr-2001i-snip4-7.eps.apple.com [57.103.68.110]) (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 9EA0B17B505 for ; Mon, 10 Aug 2026 10:22:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=57.103.68.110 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786357371; cv=none; b=Tj4DiAsheiW/wYsbvFiEDWxnaoc/rQ/vzg+D6j1e3Ug0l4QRYPR8sUmD6137VWq0eCGXgkzieI5NEi0V0RqINw+ASccYCwrkU+kKVVuWe6IBvzqGl2XpgMIQceUmeWvrcWlOn8fhS/yP2sgovTOCB/5Cqw5qR4Ez2woMB37GNpw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786357371; c=relaxed/simple; bh=3LOEJNXtjFEiOOH8294GIrC1UQolDXX0nU0bk6m0bCE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=X05xzrWkkh2QLjtDTGR8wsY3jA92h8OOrq8cjQvpQBm1IEW9qrwHSNeB3oTRSMTkzG8gVxHjtn8ZygmWV9GXmwD7NQNKfJ+m8apxmAmlwOi033ygJHgGmmzyKTYE1Ur89AeVc6U9BmAIsYdJdGO9Q3+botMSd5+hSXQAA1ugQL8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com; spf=pass smtp.mailfrom=icloud.com; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b=jiaKgkLW; arc=none smtp.client-ip=57.103.68.110 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=icloud.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b="jiaKgkLW" Received: from outbound.mr.icloud.com (unknown [127.0.0.2]) by p00-icloudmta-asmtp-us-west-2a-60-percent-6 (Postfix) with ESMTPS id B99AF1800170; Mon, 10 Aug 2026 10:22:48 +0000 (UTC) X-ICL-RepId: 019feb32-477c-7ecf-888e-8458d8777f30 X-ICL-Out-Info: HUtFAUMEWwJACUgBTUQeDx5WFlZNRAJCTQ1PHVwPUxxGClYCVAFLVxQEHUAFVgpcQglLAi1eCF4fTBwdDlgGEhZdRVoOWwRHFBcbXAAXGVFNCEkTBVIHXU1WDUcPWB5cFBcVQUNeCF4fTBwdDlgGEgBNCg42BlkFXglWA0MFNhIUXUVaDlsERxQXG1wAFwZbFAREAV0FXQJICEgCXQVZAUcXSgJbAFMFQhRJHghEA1MRV0oDXgYrWxNVF0YJGQhdHQdYRxRHDg8ZWhRcGFM= Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1786357370; x=1788949370; bh=pCDaUqi75J+60IGlSuOZ0Z5KyC1+rrvU9UrfvESnsMg=; h=From:To:Subject:Date:Message-ID:MIME-Version:x-icloud-hme; b=jiaKgkLWyqZ0PPa5x0rxnQV4gMhAwxGc8Dfm/J8UA2NNaWizOsydQ262lAxi0OsZNCzI5qVNryv+I6iUNo1y89/CxARKw47BmWtg/0VI3mMHQ8Mnb2CcCBwU0sa4lxqtXzjMTr9bQ0gta/197wpVh88HU77OXIPxzRNlRKoX5RspUrUAhDKiHL2OA28fZriiXdWrZ5yD7CUlNc1Z6czqhYh3JT0GapXT0gR3AFqv/z3NVTz39cs7scxGLK7SUwtxHgfJrdUXAcLFu897dFSb+c5Uld1o2PHj4sO6Ifbutxm9v7Fo1/ezIiMKW5CZyQ0UyjgVgjhg1dDNtufXoHxzbQ== Received: from machine (unknown [17.57.152.38]) by p00-icloudmta-asmtp-us-west-2a-60-percent-6 (Postfix) with ESMTPSA id A636518000B8; Mon, 10 Aug 2026 10:22:47 +0000 (UTC) From: Eshaan Deshmukh To: ardb@kernel.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org Cc: ilias.apalodimas@linaro.org, hpa@zytor.com, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Eshaan Deshmukh Subject: [PATCH] x86/efi: Handle errors for efi_map_region_fixed() Date: Mon, 10 Aug 2026 05:22:37 -0500 Message-ID: <20260810102237.2167872-1-eshaan2031@icloud.com> X-Mailer: git-send-email 2.55.0 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 X-Authority-Info-Out: v=2.4 cv=H4/WAuYi c=1 sm=1 tr=0 ts=6a79a679 cx=c_apl:c_pps:t_out a=9OgfyREA4BUYbbCgc0Y0oA==:117 a=9OgfyREA4BUYbbCgc0Y0oA==:17 a=Sv0fKeRqtYgA:10 a=x7bEGLp0ZPQA:10 a=ea8ixM18I5MA:10 a=VkNPw1HP01LnGYTKEx00:22 a=v3ZZPjhaAAAA:8 a=plAyUd4ex9BnA7TlT6sA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODEwMDA5MCBTYWx0ZWRfXzONqG1igsY6d fSO6tUl92gwZYGh4H9yiQoaGpdJFR7/85CV+l9AxmkLDypg5ouIPkzonFNvv+Wlj/TSIG+IPzvC 2AIZFxAC9LpUS9/44F4nbmriQ5/2QTFbLMP+Elv86D2DFuH73+7joV7/k0dqEl3DS4WEy1ylgxQ CDpyK19+bIbpx8HCLbJES1it7zv8dXkNTvPtK2APvrtYARjrbH6PCrRRpjNMSq9wHoQwSwicwh8 f33ekJQfuCybYiK7CSDu+JIHwaD3xXSWkKFBvUpa1NwC8SJ9aD4rWfKZypIXk29nhworRImj89v oOspFKvl1bcYj9jtRDv4HiwMLlI4kGlKCpdNFYU122eQNDQ/tNCuifueZWu3pY= X-Proofpoint-GUID: sdTPgo80LpwdzcV63QNvusWkRep5U657 X-Proofpoint-ORIG-GUID: sdTPgo80LpwdzcV63QNvusWkRep5U657 Content-Type: text/plain; charset="utf-8" The function efi_map_region_fixed() ignores the errors returned from kernel_map_pages_in_pgd(). If mapping failes, this can cause page faults. Update __map_region() and efi_map_region_fixed() to return the error code from kernel_map_pages_in_pgd(). If there is an error, efi_map_region_fixed() logs an error message using pr_err(), disables EFI runtime services, and returns. Signed-off-by: Eshaan Deshmukh --- arch/x86/include/asm/efi.h | 2 +- arch/x86/platform/efi/efi.c | 10 ++++++++-- arch/x86/platform/efi/efi_32.c | 6 +++++- arch/x86/platform/efi/efi_64.c | 20 ++++++++++++++------ 4 files changed, 28 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index be58b7f5c..04952e064 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -128,7 +128,7 @@ extern bool efi_disable_ibt_for_runtime; extern int __init efi_memblock_x86_reserve_range(void); extern void __init efi_print_memmap(void); extern void __init efi_map_region(efi_memory_desc_t *md); -extern void __init efi_map_region_fixed(efi_memory_desc_t *md); +extern int __init efi_map_region_fixed(efi_memory_desc_t *md); extern void efi_sync_low_kernel_mappings(void); extern int __init efi_alloc_page_tables(void); extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned = num_pages); diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 0c39adb96..4b875843a 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -735,8 +735,14 @@ static void __init kexec_enter_virtual_mode(void) * Map efi regions which were passed via setup_data. The virt_addr is a * fixed addr which was used in first kernel of a kexec boot. */ - for_each_efi_memory_desc(md) - efi_map_region_fixed(md); /* FIXME: add error handling */ + for_each_efi_memory_desc(md) { + if (efi_map_region_fixed(md)) { + pr_err("Failed to map fixed EFI region\n"); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); + return; + } + + } =20 /* * Unregister the early EFI memmap from efi_init() and install diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c index b2cc7b455..9307999b9 100644 --- a/arch/x86/platform/efi/efi_32.c +++ b/arch/x86/platform/efi/efi_32.c @@ -84,7 +84,11 @@ int __init efi_setup_page_tables(unsigned long pa_memmap= , unsigned num_pages) return 0; } =20 -void __init efi_map_region_fixed(efi_memory_desc_t *md) {} +int __init efi_map_region_fixed(efi_memory_desc_t *md) +{ + return 0; +} + void __init parse_efi_setup(u64 phys_addr, u32 data_len) {} =20 efi_status_t efi_call_svam(efi_runtime_services_t * const *, diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 5861008ea..05f1df6ca 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -269,12 +269,12 @@ int __init efi_setup_page_tables(unsigned long pa_mem= map, unsigned num_pages) return 0; } =20 -static void __init __map_region(efi_memory_desc_t *md, u64 va) +static int __init __map_region(efi_memory_desc_t *md, u64 va) { unsigned long flags =3D _PAGE_RW; unsigned long pfn; pgd_t *pgd =3D efi_mm.pgd; - + int error; /* * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF * executable images in memory that consist of both R-X and @@ -299,9 +299,11 @@ static void __init __map_region(efi_memory_desc_t *md,= u64 va) flags |=3D _PAGE_ENC; =20 pfn =3D md->phys_addr >> PAGE_SHIFT; - if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags)) + error =3D kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags); + if (error) pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n", md->phys_addr, va); + return error; } =20 void __init efi_map_region(efi_memory_desc_t *md) @@ -357,10 +359,16 @@ void __init efi_map_region(efi_memory_desc_t *md) * md->virt_addr is the original virtual address which had been mapped in = kexec * 1st kernel. */ -void __init efi_map_region_fixed(efi_memory_desc_t *md) +int __init efi_map_region_fixed(efi_memory_desc_t *md) { - __map_region(md, md->phys_addr); - __map_region(md, md->virt_addr); + int error; + + error =3D __map_region(md, md->phys_addr); + + if (error) + return error; + + return __map_region(md, md->virt_addr); } =20 void __init parse_efi_setup(u64 phys_addr, u32 data_len) --=20 2.55.0