From: Mark Rutland <mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org, will.deacon@arm.com Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, dave.martin@arm.com, hch@infradead.org, james.morse@arm.com, linux@dominikbrodowski.net, linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, viro@zeniv.linux.org.uk Subject: [PATCHv4 11/19] arm64: don't reload GPRs after apply_ssbd Date: Mon, 2 Jul 2018 12:04:07 +0100 [thread overview] Message-ID: <20180702110415.10465-12-mark.rutland@arm.com> (raw) In-Reply-To: <20180702110415.10465-1-mark.rutland@arm.com> Now that all of the syscall logic works on the saved pt_regs, apply_ssbd can safely corrupt x0-x3 in the entry paths, and we no longer need to restore them. So let's remove the logic doing so. With that logic gone, we can fold the branch target into the macro, so that callers need not deal with this. GAS provides \@, which provides a unique value per macro invocation, which we can use to create a unique label. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/entry.S | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c41b84d06644..728bc7cc5bbb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -130,20 +130,21 @@ alternative_else_nop_endif // This macro corrupts x0-x3. It is the caller's duty // to save/restore them if required. - .macro apply_ssbd, state, targ, tmp1, tmp2 + .macro apply_ssbd, state, tmp1, tmp2 #ifdef CONFIG_ARM64_SSBD alternative_cb arm64_enable_wa2_handling - b \targ + b skip_apply_ssbd\@ alternative_cb_end ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 - cbz \tmp2, \targ + cbz \tmp2, skip_apply_ssbd\@ ldr \tmp2, [tsk, #TSK_TI_FLAGS] - tbnz \tmp2, #TIF_SSBD, \targ + tbnz \tmp2, #TIF_SSBD, skip_apply_ssbd\@ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 mov w1, #\state alternative_cb arm64_update_smccc_conduit nop // Patched to SMC/HVC #0 alternative_cb_end +skip_apply_ssbd\@: #endif .endm @@ -173,13 +174,7 @@ alternative_cb_end ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug disable_step_tsk x19, x20 // exceptions when scheduling. - apply_ssbd 1, 1f, x22, x23 - -#ifdef CONFIG_ARM64_SSBD - ldp x0, x1, [sp, #16 * 0] - ldp x2, x3, [sp, #16 * 1] -#endif -1: + apply_ssbd 1, x22, x23 mov x29, xzr // fp pointed to user-space .else @@ -321,8 +316,7 @@ alternative_if ARM64_WORKAROUND_845719 alternative_else_nop_endif #endif 3: - apply_ssbd 0, 5f, x0, x1 -5: + apply_ssbd 0, x0, x1 .endif msr elr_el1, x21 // set up the return data -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: mark.rutland@arm.com (Mark Rutland) To: linux-arm-kernel@lists.infradead.org Subject: [PATCHv4 11/19] arm64: don't reload GPRs after apply_ssbd Date: Mon, 2 Jul 2018 12:04:07 +0100 [thread overview] Message-ID: <20180702110415.10465-12-mark.rutland@arm.com> (raw) In-Reply-To: <20180702110415.10465-1-mark.rutland@arm.com> Now that all of the syscall logic works on the saved pt_regs, apply_ssbd can safely corrupt x0-x3 in the entry paths, and we no longer need to restore them. So let's remove the logic doing so. With that logic gone, we can fold the branch target into the macro, so that callers need not deal with this. GAS provides \@, which provides a unique value per macro invocation, which we can use to create a unique label. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/entry.S | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c41b84d06644..728bc7cc5bbb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -130,20 +130,21 @@ alternative_else_nop_endif // This macro corrupts x0-x3. It is the caller's duty // to save/restore them if required. - .macro apply_ssbd, state, targ, tmp1, tmp2 + .macro apply_ssbd, state, tmp1, tmp2 #ifdef CONFIG_ARM64_SSBD alternative_cb arm64_enable_wa2_handling - b \targ + b skip_apply_ssbd\@ alternative_cb_end ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 - cbz \tmp2, \targ + cbz \tmp2, skip_apply_ssbd\@ ldr \tmp2, [tsk, #TSK_TI_FLAGS] - tbnz \tmp2, #TIF_SSBD, \targ + tbnz \tmp2, #TIF_SSBD, skip_apply_ssbd\@ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 mov w1, #\state alternative_cb arm64_update_smccc_conduit nop // Patched to SMC/HVC #0 alternative_cb_end +skip_apply_ssbd\@: #endif .endm @@ -173,13 +174,7 @@ alternative_cb_end ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug disable_step_tsk x19, x20 // exceptions when scheduling. - apply_ssbd 1, 1f, x22, x23 - -#ifdef CONFIG_ARM64_SSBD - ldp x0, x1, [sp, #16 * 0] - ldp x2, x3, [sp, #16 * 1] -#endif -1: + apply_ssbd 1, x22, x23 mov x29, xzr // fp pointed to user-space .else @@ -321,8 +316,7 @@ alternative_if ARM64_WORKAROUND_845719 alternative_else_nop_endif #endif 3: - apply_ssbd 0, 5f, x0, x1 -5: + apply_ssbd 0, x0, x1 .endif msr elr_el1, x21 // set up the return data -- 2.11.0
next prev parent reply other threads:[~2018-07-02 11:07 UTC|newest] Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-07-02 11:03 [PATCHv4 00/19] arm64: invoke syscalls with pt_regs Mark Rutland 2018-07-02 11:03 ` Mark Rutland 2018-07-02 11:03 ` [PATCHv4 01/19] arm64: consistently use unsigned long for thread flags Mark Rutland 2018-07-02 11:03 ` Mark Rutland 2018-07-02 11:03 ` [PATCHv4 02/19] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland 2018-07-02 11:03 ` [PATCHv4 02/19] arm64: move SCTLR_EL{1, 2} " Mark Rutland 2018-07-02 11:03 ` [PATCHv4 03/19] arm64: kill config_sctlr_el1() Mark Rutland 2018-07-02 11:03 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 04/19] arm64: kill change_cpacr() Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 05/19] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland 2018-07-02 11:04 ` [PATCHv4 05/19] arm64: move sve_user_{enable, disable} " Mark Rutland 2018-07-02 11:04 ` [PATCHv4 06/19] arm64: remove sigreturn wrappers Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 07/19] arm64: convert raw syscall invocation to C Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 08/19] arm64: convert syscall trace logic " Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 09/19] arm64: convert native/compat syscall entry " Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 10/19] arm64: don't restore GPRs when context tracking Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` Mark Rutland [this message] 2018-07-02 11:04 ` [PATCHv4 11/19] arm64: don't reload GPRs after apply_ssbd Mark Rutland 2018-07-06 16:38 ` Will Deacon 2018-07-06 16:38 ` Will Deacon 2018-07-09 14:21 ` Mark Rutland 2018-07-09 14:21 ` Mark Rutland 2018-07-10 10:37 ` Dave Martin 2018-07-10 10:37 ` Dave Martin 2018-07-10 10:37 ` Dave Martin 2018-07-10 17:33 ` Will Deacon 2018-07-10 17:33 ` Will Deacon 2018-07-10 17:33 ` Will Deacon 2018-07-11 9:46 ` Mark Rutland 2018-07-11 9:46 ` Mark Rutland 2018-07-11 9:46 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 12/19] arm64: zero GPRs upon entry from EL0 Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 13/19] kernel: add ksys_personality() Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 14/19] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 15/19] arm64: remove in-kernel call to sys_personality() Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 16/19] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 17/19] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 18/19] arm64: convert compat wrappers to C Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-02 11:04 ` [PATCHv4 19/19] arm64: implement syscall wrappers Mark Rutland 2018-07-02 11:04 ` Mark Rutland 2018-07-06 16:42 ` [PATCHv4 00/19] arm64: invoke syscalls with pt_regs Will Deacon 2018-07-06 16:42 ` Will Deacon 2018-07-10 10:39 ` Will Deacon 2018-07-10 10:39 ` Will Deacon 2018-07-11 10:47 ` Mark Rutland 2018-07-11 10:47 ` Mark Rutland 2018-07-11 12:27 ` Will Deacon 2018-07-11 12:27 ` Will Deacon
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