From: James Morse <james.morse@arm.com>
To: stable@vger.kernel.org
Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
james.morse@arm.com
Subject: [stable:PATCH v5.4.184 16/22] arm64: entry: Add macro for reading symbol addresses from the trampoline
Date: Tue, 15 Mar 2022 18:24:09 +0000 [thread overview]
Message-ID: <20220315182415.3900464-17-james.morse@arm.com> (raw)
In-Reply-To: <20220315182415.3900464-1-james.morse@arm.com>
commit b28a8eebe81c186fdb1a0078263b30576c8e1f42 upstream.
The trampoline code needs to use the address of symbols in the wider
kernel, e.g. vectors. PC-relative addressing wouldn't work as the
trampoline code doesn't run at the address the linker expected.
tramp_ventry uses a literal pool, unless CONFIG_RANDOMIZE_BASE is
set, in which case it uses the data page as a literal pool because
the data page can be unmapped when running in user-space, which is
required for CPUs vulnerable to meltdown.
Pull this logic out as a macro, instead of adding a third copy
of it.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
arch/arm64/kernel/entry.S | 35 ++++++++++++++++-------------------
1 file changed, 16 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 14351ee5e812..e4b5a15c2e2e 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1063,6 +1063,15 @@ alternative_else_nop_endif
sub \dst, \dst, PAGE_SIZE
.endm
+ .macro tramp_data_read_var dst, var
+#ifdef CONFIG_RANDOMIZE_BASE
+ tramp_data_page \dst
+ add \dst, \dst, #:lo12:__entry_tramp_data_\var
+ ldr \dst, [\dst]
+#else
+ ldr \dst, =\var
+#endif
+ .endm
#define BHB_MITIGATION_NONE 0
#define BHB_MITIGATION_LOOP 1
@@ -1093,13 +1102,8 @@ alternative_else_nop_endif
b .
2:
tramp_map_kernel x30
-#ifdef CONFIG_RANDOMIZE_BASE
- tramp_data_page x30
alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003
- ldr x30, [x30]
-#else
- ldr x30, =vectors
-#endif
+ tramp_data_read_var x30, vectors
alternative_if_not ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM
prfm plil1strm, [x30, #(1b - \vector_start)]
alternative_else_nop_endif
@@ -1183,7 +1187,12 @@ END(tramp_exit_compat)
.align PAGE_SHIFT
.globl __entry_tramp_data_start
__entry_tramp_data_start:
+__entry_tramp_data_vectors:
.quad vectors
+#ifdef CONFIG_ARM_SDE_INTERFACE
+__entry_tramp_data___sdei_asm_trampoline_next_handler:
+ .quad __sdei_asm_handler
+#endif /* CONFIG_ARM_SDE_INTERFACE */
.popsection // .rodata
#endif /* CONFIG_RANDOMIZE_BASE */
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
@@ -1310,13 +1319,7 @@ ENTRY(__sdei_asm_entry_trampoline)
*/
1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)]
-#ifdef CONFIG_RANDOMIZE_BASE
- tramp_data_page x4
- add x4, x4, #:lo12:__sdei_asm_trampoline_next_handler
- ldr x4, [x4]
-#else
- ldr x4, =__sdei_asm_handler
-#endif
+ tramp_data_read_var x4, __sdei_asm_trampoline_next_handler
br x4
ENDPROC(__sdei_asm_entry_trampoline)
NOKPROBE(__sdei_asm_entry_trampoline)
@@ -1339,12 +1342,6 @@ ENDPROC(__sdei_asm_exit_trampoline)
NOKPROBE(__sdei_asm_exit_trampoline)
.ltorg
.popsection // .entry.tramp.text
-#ifdef CONFIG_RANDOMIZE_BASE
-.pushsection ".rodata", "a"
-__sdei_asm_trampoline_next_handler:
- .quad __sdei_asm_handler
-.popsection // .rodata
-#endif /* CONFIG_RANDOMIZE_BASE */
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
/*
--
2.30.2
next prev parent reply other threads:[~2022-03-15 18:24 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 18:23 [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 01/22] arm64: Add part number for Arm Cortex-A77 James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 02/22] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 03/22] arm64: add ID_AA64ISAR2_EL1 sys register James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 04/22] arm64: Add Cortex-X2 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 05/22] arm64: entry.S: Add ventry overflow sanity checks James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 06/22] arm64: entry: Make the trampoline cleanup optional James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 07/22] arm64: entry: Free up another register on kpti's tramp_exit path James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 08/22] arm64: entry: Move the trampoline data page before the text page James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 09/22] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 10/22] arm64: entry: Don't assume tramp_vectors is the start of the vectors James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 11/22] arm64: entry: Move trampoline macros out of ifdef'd section James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 12/22] arm64: entry: Make the kpti trampoline's kpti sequence optional James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 13/22] arm64: entry: Allow the trampoline text to occupy multiple pages James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 14/22] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 15/22] arm64: entry: Add vectors that have the bhb mitigation sequences James Morse
2022-03-15 18:24 ` James Morse [this message]
2022-03-15 18:24 ` [stable:PATCH v5.4.184 17/22] arm64: Add percpu vectors for EL1 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 18/22] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 19/22] KVM: arm64: Add templates for BHB mitigation sequences James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 20/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 21/22] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 22/22] arm64: Use the clearbhb instruction in mitigations James Morse
2022-03-16 15:41 ` [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels Sasha Levin
2022-03-16 17:38 ` James Morse
2022-03-16 18:43 ` Sasha Levin
2022-03-17 10:00 ` Greg KH
2022-03-18 12:15 ` James Morse
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