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* [PATCHv3 0/3] clean up KPTI / SDEI trampoline data alignment
@ 2020-03-19  9:12 Rémi Denis-Courmont
  2020-03-19  9:14 ` [PATCH 1/3] arm64: clean up trampoline vector loads Rémi Denis-Courmont
                   ` (4 more replies)
  0 siblings, 5 replies; 18+ messages in thread
From: Rémi Denis-Courmont @ 2020-03-19  9:12 UTC (permalink / raw)
  To: Catalin Marinas, Will Deacon, linux-arm-kernel
  Cc: Mark Rutland, James Morse, linux-kernel

	Hi,

The KPTI and SDE trampolines each load a pointer from the same fixmap data
page. This reduces the data alignment to the useful value, and tries to
clarify the assembler code.

Changes since v2:
- Retain alignment even when SDEI is disabled to keep ld happy.

----------------------------------------------------------------
Rémi Denis-Courmont (3):
      arm64: clean up trampoline vector loads
      arm64/sdei: gather trampolines' .rodata
      arm64: reduce trampoline data alignment

 arch/arm64/kernel/entry.S | 23 ++++++++++-------------
 arch/arm64/mm/mmu.c       |  5 ++---
 2 files changed, 12 insertions(+), 16 deletions(-)

-- 
Реми Дёни-Курмон
http://www.remlab.net/




^ permalink raw reply	[flat|nested] 18+ messages in thread
* [PATCH 2/3] arm64/sdei: gather trampolines' .rodata
@ 2020-03-16 12:40 Rémi Denis-Courmont
  2020-03-17 22:32 ` Will Deacon
  0 siblings, 1 reply; 18+ messages in thread
From: Rémi Denis-Courmont @ 2020-03-16 12:40 UTC (permalink / raw)
  To: catalin.marinas, will, linux-arm-kernel; +Cc: mark.rutland, linux-kernel

From: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>

This gathers the two bits of data together for clarity.

Signed-off-by: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>
---
 arch/arm64/kernel/entry.S | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 24f828739696..af17fcb4aaea 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -859,6 +859,11 @@ SYM_CODE_END(tramp_exit_compat)
 #ifdef CONFIG_RANDOMIZE_BASE
 	.pushsection ".rodata", "a"
 	.align PAGE_SHIFT
+#ifdef CONFIG_ARM_SDE_INTERFACE
+SYM_DATA_START(__sdei_asm_trampoline_next_handler)
+	.quad	__sdei_asm_handler
+SYM_DATA_END(__sdei_asm_trampoline_next_handler)
+#endif
 SYM_DATA_START(__entry_tramp_data_start)
 	.quad	vectors
 SYM_DATA_END(__entry_tramp_data_start)
@@ -980,13 +985,6 @@ SYM_CODE_END(__sdei_asm_exit_trampoline)
 NOKPROBE(__sdei_asm_exit_trampoline)
 	.ltorg
 .popsection		// .entry.tramp.text
-#ifdef CONFIG_RANDOMIZE_BASE
-.pushsection ".rodata", "a"
-SYM_DATA_START(__sdei_asm_trampoline_next_handler)
-	.quad	__sdei_asm_handler
-SYM_DATA_END(__sdei_asm_trampoline_next_handler)
-.popsection		// .rodata
-#endif /* CONFIG_RANDOMIZE_BASE */
 #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
 
 /*
-- 
2.25.1


^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2020-03-24 11:23 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-19  9:12 [PATCHv3 0/3] clean up KPTI / SDEI trampoline data alignment Rémi Denis-Courmont
2020-03-19  9:14 ` [PATCH 1/3] arm64: clean up trampoline vector loads Rémi Denis-Courmont
2020-03-23 12:07   ` Mark Rutland
2020-03-23 12:08     ` Rémi Denis-Courmont
2020-03-23 12:14       ` Mark Rutland
2020-03-23 19:04         ` Catalin Marinas
2020-03-23 20:42           ` Rémi Denis-Courmont
2020-03-24 10:37             ` Catalin Marinas
2020-03-24 10:52             ` Mark Rutland
2020-03-24 11:23               ` Catalin Marinas
2020-03-19  9:14 ` [PATCH 2/3] arm64/sdei: gather trampolines' .rodata Rémi Denis-Courmont
2020-03-19  9:14 ` [PATCH 3/3] arm64: reduce trampoline data alignment Rémi Denis-Courmont
2020-03-21 13:41   ` Catalin Marinas
2020-03-23 11:58     ` Mark Rutland
2020-03-19 18:37 ` [PATCHv3 0/3] clean up KPTI / SDEI " Will Deacon
2020-03-20 16:54 ` Catalin Marinas
  -- strict thread matches above, loose matches on Subject: below --
2020-03-16 12:40 [PATCH 2/3] arm64/sdei: gather trampolines' .rodata Rémi Denis-Courmont
2020-03-17 22:32 ` Will Deacon

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