From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Kees Cook <keescook@chromium.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Brown <broonie@kernel.org>
Subject: [PATCH v3 25/30] arm64: head: record the MMU state at primary entry
Date: Mon, 11 Apr 2022 11:48:19 +0200 [thread overview]
Message-ID: <20220411094824.4176877-26-ardb@kernel.org> (raw)
In-Reply-To: <20220411094824.4176877-1-ardb@kernel.org>
Prepare for being able to deal with primary entry with the MMU and
caches enabled, by recording whether or not we entered with the MMU on
in register x22.
While at it, add disable_mmu_workaround macro invocations to
init_kernel_el, as its manipulation of SCTLR_ELx may come down to
disabling of the MMU after subsequent patches.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/kernel/head.S | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index cba9a5e8abb8..1ff474701e99 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -85,10 +85,12 @@
* x19 create_idmap() .. __ start_kernel() ID map VA of the DT blob
* x20 primary_entry() .. __primary_switch() CPU boot mode
* x21 primary_entry() .. start_kernel() FDT pointer passed at boot in x0
+ * x22 primary_entry() .. start_kernel() whether we entered with the MMU on
* x23 __primary_switch() .. relocate_kernel() physical misalignment/KASLR offset
* x28 create_idmap(), remap_kernel_text() callee preserved temp register
*/
SYM_CODE_START(primary_entry)
+ bl record_mmu_state
bl preserve_boot_args
bl init_kernel_el // w0=cpu_boot_mode
mov x20, x0
@@ -104,6 +106,17 @@ SYM_CODE_START(primary_entry)
b __primary_switch
SYM_CODE_END(primary_entry)
+SYM_CODE_START_LOCAL(record_mmu_state)
+ mrs x22, CurrentEL
+ cmp x22, #CurrentEL_EL2
+ mrs x22, sctlr_el1
+ b.ne 0f
+ mrs x22, sctlr_el2
+0: tst x22, #SCTLR_ELx_M
+ cset w22, ne
+ ret
+SYM_CODE_END(record_mmu_state)
+
/*
* Preserve the arguments passed by the bootloader in x0 .. x3
*/
@@ -528,6 +541,7 @@ SYM_FUNC_START(init_kernel_el)
SYM_INNER_LABEL(init_el1, SYM_L_LOCAL)
mov_q x0, INIT_SCTLR_EL1_MMU_OFF
+ pre_disable_mmu_workaround
msr sctlr_el1, x0
isb
mov_q x0, INIT_PSTATE_EL1
@@ -559,6 +573,7 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL)
/* Switching to VHE requires a sane SCTLR_EL1 as a start */
mov_q x0, INIT_SCTLR_EL1_MMU_OFF
+ pre_disable_mmu_workaround
msr_s SYS_SCTLR_EL12, x0
/*
@@ -574,6 +589,7 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL)
1:
mov_q x0, INIT_SCTLR_EL1_MMU_OFF
+ pre_disable_mmu_workaround
msr sctlr_el1, x0
msr elr_el2, lr
--
2.30.2
next prev parent reply other threads:[~2022-04-11 9:51 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 9:47 [PATCH v3 00/30] arm64: support WXN and entry with MMU enabled Ard Biesheuvel
2022-04-11 9:47 ` [PATCH v3 01/30] arm64: head: move kimage_vaddr variable into C file Ard Biesheuvel
2022-04-11 9:47 ` [PATCH v3 02/30] arm64: mm: make vabits_actual a build time constant if possible Ard Biesheuvel
2022-04-11 9:47 ` [PATCH v3 03/30] arm64: head: move assignment of idmap_t0sz to C code Ard Biesheuvel
2022-04-11 9:47 ` [PATCH v3 04/30] arm64: head: drop idmap_ptrs_per_pgd Ard Biesheuvel
2022-04-11 9:47 ` [PATCH v3 05/30] arm64: head: simplify page table mapping macros (slightly) Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 06/30] arm64: head: switch to map_memory macro for the extended ID map Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 07/30] arm64: head: split off idmap creation code Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 08/30] arm64: kernel: drop unnecessary PoC cache clean+invalidate Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 09/30] arm64: head: pass ID map root table address to __enable_mmu() Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 10/30] arm64: mm: provide idmap pointer to cpu_replace_ttbr1() Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 11/30] arm64: head: add helper function to remap regions in early page tables Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 12/30] arm64: head: cover entire kernel image in initial ID map Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 13/30] arm64: head: use relative references to the RELA and RELR tables Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 14/30] arm64: head: create a temporary FDT mapping in the initial ID map Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 15/30] arm64: idreg-override: use early FDT mapping in " Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 16/30] arm64: head: factor out TTBR1 assignment into a macro Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 17/30] arm64: head: populate kernel page tables with MMU and caches on Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 18/30] arm64: head: record CPU boot mode after enabling the MMU Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 19/30] arm64: kaslr: deal with init called with VA randomization enabled Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 20/30] arm64: head: relocate kernel only a single time if KASLR is enabled Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 21/30] arm64: head: remap the kernel text/inittext region read-only Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 22/30] arm64: setup: drop early FDT pointer helpers Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 23/30] arm64: mm: move ro_after_init section into the data segment Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 24/30] arm64: mm: add support for WXN memory translation attribute Ard Biesheuvel
2022-04-11 9:48 ` Ard Biesheuvel [this message]
2022-04-11 9:48 ` [PATCH v3 26/30] arm64: head: avoid cache invalidation when entering with the MMU on Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 27/30] arm64: head: clean the ID map page to the PoC Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 28/30] efi: libstub: pass image handle to handle_kernel_image() Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 29/30] efi/arm64: libstub: run image in place if randomized by the loader Ard Biesheuvel
2022-04-11 9:48 ` [PATCH v3 30/30] arm64: efi/libstub: enter with the MMU on if executing in place Ard Biesheuvel
2022-04-12 16:59 ` [PATCH v3 00/30] arm64: support WXN and entry with MMU enabled Kees Cook
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