From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Joey Gouly <joey.gouly@arm.com>, Mark Rutland <mark.rutland@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Sasha Levin <sashal@kernel.org>, ardb@kernel.org, tabba@google.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.17 28/49] arm64: alternatives: mark patch_alternative() as `noinstr` Date: Mon, 11 Apr 2022 20:43:46 -0400 [thread overview] Message-ID: <20220412004411.349427-28-sashal@kernel.org> (raw) In-Reply-To: <20220412004411.349427-1-sashal@kernel.org> From: Joey Gouly <joey.gouly@arm.com> [ Upstream commit a2c0b0fbe01419f8f5d1c0b9c581631f34ffce8b ] The alternatives code must be `noinstr` such that it does not patch itself, as the cache invalidation is only performed after all the alternatives have been applied. Mark patch_alternative() as `noinstr`. Mark branch_insn_requires_update() and get_alt_insn() with `__always_inline` since they are both only called through patch_alternative(). Booting a kernel in QEMU TCG with KCSAN=y and ARM64_USE_LSE_ATOMICS=y caused a boot hang: [ 0.241121] CPU: All CPU(s) started at EL2 The alternatives code was patching the atomics in __tsan_read4() from LL/SC atomics to LSE atomics. The following fragment is using LL/SC atomics in the .text section: | <__tsan_unaligned_read4+304>: ldxr x6, [x2] | <__tsan_unaligned_read4+308>: add x6, x6, x5 | <__tsan_unaligned_read4+312>: stxr w7, x6, [x2] | <__tsan_unaligned_read4+316>: cbnz w7, <__tsan_unaligned_read4+304> This LL/SC atomic sequence was to be replaced with LSE atomics. However since the alternatives code was instrumentable, __tsan_read4() was being called after only the first instruction was replaced, which led to the following code in memory: | <__tsan_unaligned_read4+304>: ldadd x5, x6, [x2] | <__tsan_unaligned_read4+308>: add x6, x6, x5 | <__tsan_unaligned_read4+312>: stxr w7, x6, [x2] | <__tsan_unaligned_read4+316>: cbnz w7, <__tsan_unaligned_read4+304> This caused an infinite loop as the `stxr` instruction never completed successfully, so `w7` was always 0. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220405104733.11476-1-joey.gouly@arm.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/arm64/kernel/alternative.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 3fb79b76e9d9..7bbf5104b7b7 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -42,7 +42,7 @@ bool alternative_is_applied(u16 cpufeature) /* * Check if the target PC is within an alternative block. */ -static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) +static __always_inline bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) { unsigned long replptr = (unsigned long)ALT_REPL_PTR(alt); return !(pc >= replptr && pc <= (replptr + alt->alt_len)); @@ -50,7 +50,7 @@ static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) #define align_down(x, a) ((unsigned long)(x) & ~(((unsigned long)(a)) - 1)) -static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr) +static __always_inline u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr) { u32 insn; @@ -95,7 +95,7 @@ static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnp return insn; } -static void patch_alternative(struct alt_instr *alt, +static noinstr void patch_alternative(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst) { __le32 *replptr; -- 2.35.1
WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Joey Gouly <joey.gouly@arm.com>, Mark Rutland <mark.rutland@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Sasha Levin <sashal@kernel.org>, ardb@kernel.org, tabba@google.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.17 28/49] arm64: alternatives: mark patch_alternative() as `noinstr` Date: Mon, 11 Apr 2022 20:43:46 -0400 [thread overview] Message-ID: <20220412004411.349427-28-sashal@kernel.org> (raw) In-Reply-To: <20220412004411.349427-1-sashal@kernel.org> From: Joey Gouly <joey.gouly@arm.com> [ Upstream commit a2c0b0fbe01419f8f5d1c0b9c581631f34ffce8b ] The alternatives code must be `noinstr` such that it does not patch itself, as the cache invalidation is only performed after all the alternatives have been applied. Mark patch_alternative() as `noinstr`. Mark branch_insn_requires_update() and get_alt_insn() with `__always_inline` since they are both only called through patch_alternative(). Booting a kernel in QEMU TCG with KCSAN=y and ARM64_USE_LSE_ATOMICS=y caused a boot hang: [ 0.241121] CPU: All CPU(s) started at EL2 The alternatives code was patching the atomics in __tsan_read4() from LL/SC atomics to LSE atomics. The following fragment is using LL/SC atomics in the .text section: | <__tsan_unaligned_read4+304>: ldxr x6, [x2] | <__tsan_unaligned_read4+308>: add x6, x6, x5 | <__tsan_unaligned_read4+312>: stxr w7, x6, [x2] | <__tsan_unaligned_read4+316>: cbnz w7, <__tsan_unaligned_read4+304> This LL/SC atomic sequence was to be replaced with LSE atomics. However since the alternatives code was instrumentable, __tsan_read4() was being called after only the first instruction was replaced, which led to the following code in memory: | <__tsan_unaligned_read4+304>: ldadd x5, x6, [x2] | <__tsan_unaligned_read4+308>: add x6, x6, x5 | <__tsan_unaligned_read4+312>: stxr w7, x6, [x2] | <__tsan_unaligned_read4+316>: cbnz w7, <__tsan_unaligned_read4+304> This caused an infinite loop as the `stxr` instruction never completed successfully, so `w7` was always 0. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220405104733.11476-1-joey.gouly@arm.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/arm64/kernel/alternative.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 3fb79b76e9d9..7bbf5104b7b7 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -42,7 +42,7 @@ bool alternative_is_applied(u16 cpufeature) /* * Check if the target PC is within an alternative block. */ -static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) +static __always_inline bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) { unsigned long replptr = (unsigned long)ALT_REPL_PTR(alt); return !(pc >= replptr && pc <= (replptr + alt->alt_len)); @@ -50,7 +50,7 @@ static bool branch_insn_requires_update(struct alt_instr *alt, unsigned long pc) #define align_down(x, a) ((unsigned long)(x) & ~(((unsigned long)(a)) - 1)) -static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr) +static __always_inline u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr) { u32 insn; @@ -95,7 +95,7 @@ static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnp return insn; } -static void patch_alternative(struct alt_instr *alt, +static noinstr void patch_alternative(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst) { __le32 *replptr; -- 2.35.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-04-12 0:47 UTC|newest] Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-12 0:43 [PATCH AUTOSEL 5.17 01/49] KVM: PPC: Book3S HV P9: Fix "lost kick" race Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 02/49] drm/amd: Add USBC connector ID Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 03/49] btrfs: fix fallocate to use file_modified to update permissions consistently Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 04/49] btrfs: do not warn for free space inode in cow_file_range Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 05/49] drm/amdgpu: conduct a proper cleanup of PDB bo Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 06/49] drm/amdgpu/gmc: use PCI BARs for APUs in passthrough Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 07/49] drm/amd/display: fix audio format not updated after edid updated Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 08/49] drm/amd/display: FEC check in timing validation Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 09/49] drm/amd/display: Update VTEM Infopacket definition Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 10/49] drm/amdkfd: Fix Incorrect VMIDs passed to HWS Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 11/49] drm/amdgpu/vcn: improve vcn dpg stop procedure Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 12/49] drm/amdkfd: Check for potential null return of kmalloc_array() Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 13/49] Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 14/49] Drivers: hv: vmbus: Propagate VMbus coherence to each VMbus device Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 15/49] PCI: hv: Propagate coherence from VMbus device to PCI device Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 16/49] Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 17/49] scsi: target: tcmu: Fix possible page UAF Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 18/49] scsi: lpfc: Improve PCI EEH Error and Recovery Handling Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 19/49] scsi: lpfc: Fix unload hang after back to back PCI EEH faults Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 20/49] scsi: lpfc: Fix queue failures when recovering from PCI parity error Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 21/49] scsi: ibmvscsis: Increase INITIAL_SRP_LIMIT to 1024 Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 22/49] net: micrel: fix KS8851_MLL Kconfig Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 23/49] ata: libata-core: Disable READ LOG DMA EXT for Samsung 840 EVOs Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 24/49] gpu: ipu-v3: Fix dev_dbg frequency output Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 25/49] regulator: wm8994: Add an off-on delay for WM8994 variant Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 26/49] Revert "ACPI: processor: idle: Only flush cache on entering C3" Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 27/49] static_call: Properly initialise DEFINE_STATIC_CALL_RET0() Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin [this message] 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 28/49] arm64: alternatives: mark patch_alternative() as `noinstr` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 29/49] tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 30/49] net: axienet: setup mdio unconditionally Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 31/49] Drivers: hv: balloon: Disable balloon and hot-add accordingly Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 32/49] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 33/49] myri10ge: fix an incorrect free for skb in myri10ge_sw_tso Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 34/49] spi: cadence-quadspi: fix protocol setup for non-1-1-X operations Sasha Levin 2022-04-12 11:49 ` Matthias Schiffer 2022-04-12 12:07 ` Mark Brown 2022-04-17 21:33 ` Sasha Levin 2022-04-19 13:15 ` Mark Brown 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 35/49] drm/amd/display: Correct Slice reset calculation Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 36/49] drm/amd/display: Enable power gating before init_pipes Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 37/49] drm/amd/display: Revert FEC check in validation Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 38/49] drm/amd/display: Fix allocate_mst_payload assert on resume Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 39/49] drbd: set QUEUE_FLAG_STABLE_WRITES Sasha Levin 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 40/49] powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit Sasha Levin 2022-04-12 0:43 ` Sasha Levin 2022-04-12 6:35 ` Michael Ellerman 2022-04-12 6:35 ` Michael Ellerman 2022-04-12 0:43 ` [PATCH AUTOSEL 5.17 41/49] scsi: mpt3sas: Fail reset operation if config request timed out Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 42/49] scsi: mvsas: Add PCI ID of RocketRaid 2640 Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 43/49] scsi: megaraid_sas: Target with invalid LUN ID is deleted during scan Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 44/49] drivers: net: slip: fix NPD bug in sl_tx_timeout() Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 45/49] x86,bpf: Avoid IBT objtool warning Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 46/49] io_uring: zero tag on rsrc removal Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 47/49] io_uring: use nospec annotation for more indexes Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 48/49] arm64: Add part number for Arm Cortex-A78AE Sasha Levin 2022-04-12 0:44 ` Sasha Levin 2022-04-12 0:44 ` [PATCH AUTOSEL 5.17 49/49] perf/imx_ddr: Fix undefined behavior due to shift overflowing the constant Sasha Levin 2022-04-12 0:44 ` Sasha Levin
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