From: Mark Rutland <mark.rutland@arm.com>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v3 01/60] arm64: kernel: Disable latent_entropy GCC plugin in early C runtime
Date: Fri, 28 Apr 2023 12:48:47 +0100 [thread overview]
Message-ID: <ZEuyn+5ppbSkFiWV@FVFF77S0Q05N> (raw)
In-Reply-To: <CAMj1kXEueDPt9TJVh4NmFtJG-nJFgrHNsqykzQNQZPrGwRz8pg@mail.gmail.com>
On Fri, Apr 28, 2023 at 11:54:16AM +0100, Ard Biesheuvel wrote:
> On Fri, 28 Apr 2023 at 11:38, Mark Rutland <mark.rutland@arm.com> wrote:
> >
> > On Tue, Mar 07, 2023 at 03:04:23PM +0100, Ard Biesheuvel wrote:
> > > Avoid build issues in the early C code related to the latent_entropy GCC
> > > plugin, by incorporating the C flags fragment that disables it.
> > >
> > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> >
> > Just to check, are you seeing issues today? IIUC the plugin only instruments
> > functions which are explicitly marked with __latent_entropy, and if we're
> > seeing that happen unexpectedly (or due to that being applying to __meminit /
> > __init), we might need to do likewise for other noinstr code.
> >
>
> I don't quite remember, tbh, but it is unlikely that I would have
> written or included this patch without having run into some actual
> issue.
Sure.
Looking at the series, from patch 15 onwards you mark portions of the PI code
as __init. As __init currently implies __latent_entropy (which I think is a bit
crazy as of itself...), that's why this'll start to fail.
It would be nice if we could mention that in the commit message, e.g.
| In subsequent patches we'll mark portions of the early C code as __init.
| Unfortunarely, __init implies __latent_entropy, and this would result in the
| early C code being instrumented in an unsafe manner.
|
| Disable the latent entropy plugin for the early C code.
... though my ack stands regardless of whether we add such wording.
Mark.
> > Regardless, for this patch:
> >
> > Acked-by: Mark Rutland <mark.rutland@arm.com>
> >
>
> Thanks,
next prev parent reply other threads:[~2023-04-28 11:49 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-07 14:04 [PATCH v3 00/60] arm64: Add support for LPA2 at stage1 and WXN Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 01/60] arm64: kernel: Disable latent_entropy GCC plugin in early C runtime Ard Biesheuvel
2023-04-28 10:37 ` Mark Rutland
2023-04-28 10:54 ` Ard Biesheuvel
2023-04-28 11:48 ` Mark Rutland [this message]
2023-03-07 14:04 ` [PATCH v3 02/60] arm64: mm: Take potential load offset into account when KASLR is off Ard Biesheuvel
2023-04-28 10:41 ` Mark Rutland
2023-03-07 14:04 ` [PATCH v3 03/60] arm64: mm: get rid of kimage_vaddr global variable Ard Biesheuvel
2023-04-28 10:42 ` Mark Rutland
2023-03-07 14:04 ` [PATCH v3 04/60] arm64: mm: Move PCI I/O emulation region above the vmemmap region Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 05/60] arm64: mm: Move fixmap region above " Ard Biesheuvel
2023-04-28 11:00 ` Mark Rutland
2023-03-07 14:04 ` [PATCH v3 06/60] arm64: ptdump: Allow VMALLOC_END to be defined at boot Ard Biesheuvel
2023-03-07 16:58 ` Ryan Roberts
2023-03-07 17:01 ` Ard Biesheuvel
2023-04-28 11:25 ` Mark Rutland
2023-03-07 14:04 ` [PATCH v3 07/60] arm64: ptdump: Discover start of vmemmap region at runtime Ard Biesheuvel
2023-03-07 16:36 ` Ryan Roberts
2023-04-28 11:27 ` Mark Rutland
2023-03-07 14:04 ` [PATCH v3 08/60] arm64: vmemmap: Avoid base2 order of struct page size to dimension region Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 09/60] arm64: mm: Reclaim unused vmemmap region for vmalloc use Ard Biesheuvel
2023-03-07 16:42 ` Ryan Roberts
2023-03-07 16:58 ` Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 10/60] arm64: kaslr: Adjust randomization range dynamically Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 11/60] arm64: kaslr: drop special case for ThunderX in kaslr_requires_kpti() Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 12/60] arm64: Turn kaslr_feature_override into a generic SW feature override Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 13/60] arm64: kvm: honour 'nokaslr' command line option for the HYP VA space Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 14/60] arm64: kernel: Manage absolute relocations in code built under pi/ Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 15/60] arm64: kernel: Don't rely on objcopy to make code under pi/ __init Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 16/60] arm64: head: move relocation handling to C code Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 17/60] arm64: idreg-override: Omit non-NULL checks for override pointer Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 18/60] arm64: idreg-override: Prepare for place relative reloc patching Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 19/60] arm64: idreg-override: Avoid parameq() and parameqn() Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 20/60] arm64: idreg-override: avoid strlen() to check for empty strings Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 21/60] arm64: idreg-override: Avoid sprintf() for simple string concatenation Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 22/60] arm64: idreg-override: Avoid kstrtou64() to parse a single hex digit Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 23/60] arm64: idreg-override: Move to early mini C runtime Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 24/60] arm64: kernel: Remove early fdt remap code Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 25/60] arm64: head: Clear BSS and the kernel page tables in one go Ard Biesheuvel
2023-04-17 14:00 ` Ryan Roberts
2023-04-17 14:02 ` Ard Biesheuvel
2023-04-17 14:09 ` Ryan Roberts
2023-03-07 14:04 ` [PATCH v3 26/60] arm64: Move feature overrides into the BSS section Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 27/60] arm64: head: Run feature override detection before mapping the kernel Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 28/60] arm64: head: move dynamic shadow call stack patching into early C runtime Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 29/60] arm64: kaslr: Use feature override instead of parsing the cmdline again Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 30/60] arm64: idreg-override: Create a pseudo feature for rodata=off Ard Biesheuvel
2023-04-17 14:28 ` Ryan Roberts
2023-04-17 14:30 ` Ard Biesheuvel
2023-04-17 14:33 ` Ryan Roberts
2023-03-07 14:04 ` [PATCH v3 31/60] arm64: Add helpers to probe local CPU for PAC/BTI/E0PD support Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 32/60] arm64: head: allocate more pages for the kernel mapping Ard Biesheuvel
2023-04-17 15:48 ` Ryan Roberts
2023-04-17 16:11 ` Ard Biesheuvel
2023-04-17 16:18 ` Ryan Roberts
2023-03-07 14:04 ` [PATCH v3 33/60] arm64: head: move memstart_offset_seed handling to C code Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 34/60] arm64: head: Move early kernel mapping routines into " Ard Biesheuvel
2023-04-18 9:31 ` Ryan Roberts
2023-04-18 10:06 ` Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 35/60] arm64: mm: Use 48-bit virtual addressing for the permanent ID map Ard Biesheuvel
2023-04-18 10:22 ` Ryan Roberts
2023-03-07 14:04 ` [PATCH v3 36/60] arm64: pgtable: Decouple PGDIR size macros from PGD/PUD/PMD levels Ard Biesheuvel
2023-03-07 14:04 ` [PATCH v3 37/60] arm64: kernel: Create initial ID map from C code Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 38/60] arm64: mm: avoid fixmap for early swapper_pg_dir updates Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 39/60] arm64: mm: omit redundant remap of kernel image Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 40/60] arm64: Revert "mm: provide idmap pointer to cpu_replace_ttbr1()" Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 41/60] arm64/mm: Add FEAT_LPA2 specific TCR_EL1.DS field Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 42/60] arm64/mm: Add FEAT_LPA2 specific ID_AA64MMFR0.TGRAN[2] Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 43/60] arm64: mm: Handle LVA support as a CPU feature Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 44/60] arm64: mm: Add feature override support for LVA Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 45/60] arm64: mm: Wire up TCR.DS bit to PTE shareability fields Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 46/60] arm64: mm: Add LPA2 support to phys<->pte conversion routines Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 47/60] arm64: mm: Add definitions to support 5 levels of paging Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 48/60] arm64: mm: add LPA2 and 5 level paging support to G-to-nG conversion Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 49/60] arm64: Enable LPA2 at boot if supported by the system Ard Biesheuvel
2023-04-18 13:50 ` Ryan Roberts
2023-03-07 14:05 ` [PATCH v3 50/60] arm64: mm: Add 5 level paging support to fixmap and swapper handling Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 51/60] arm64: kasan: Reduce minimum shadow alignment and enable 5 level paging Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 52/60] arm64: mm: Add support for folding PUDs at runtime Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 53/60] arm64: ptdump: Disregard unaddressable VA space Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 54/60] arm64: ptdump: Deal with translation levels folded at runtime Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 55/60] arm64: kvm: avoid CONFIG_PGTABLE_LEVELS for runtime levels Ard Biesheuvel
2023-04-18 14:29 ` Ryan Roberts
2023-03-07 14:05 ` [PATCH v3 56/60] arm64: kvm: Limit HYP VA and host S2 range to 48 bits when LPA2 is in effect Ard Biesheuvel
2023-04-18 14:33 ` Ryan Roberts
2023-03-07 14:05 ` [PATCH v3 57/60] arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 58/60] arm64: defconfig: Enable LPA2 support Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 59/60] mm: add arch hook to validate mmap() prot flags Ard Biesheuvel
2023-03-07 14:05 ` [PATCH v3 60/60] arm64: mm: add support for WXN memory translation attribute Ard Biesheuvel
2023-03-07 16:28 ` [PATCH v3 00/60] arm64: Add support for LPA2 at stage1 and WXN Ryan Roberts
2023-03-08 8:31 ` Ard Biesheuvel
2023-04-18 15:01 ` Ryan Roberts
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