From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
npiggin@gmail.com, msuchanek@suse.de
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v4 21/23] powerpc/syscall: Remove FULL_REGS verification in system_call_exception
Date: Mon, 25 Jan 2021 14:48:34 +0000 (UTC) [thread overview]
Message-ID: <5e2167907bc11834a3dc7b0f08267a027dbde7f9.1611585031.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
For book3s/64, FULL_REGS() is 'true' at all time, so the test voids.
For others, non volatile registers are saved inconditionally.
So the verification is pointless.
Should one fail to do it, it would anyway be caught by the
CHECK_FULL_REGS() in copy_thread() as we have removed the
special versions ppc_fork() and friends.
null_syscall benchmark reduction 4 cycles (332 => 328 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index 30f8a397a522..a40775daa88b 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -42,7 +42,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
- BUG_ON(!FULL_REGS(regs));
BUG_ON(arch_irq_disabled_regs(regs));
#ifdef CONFIG_PPC_PKEY
--
2.25.0
next prev parent reply other threads:[~2021-01-25 15:27 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 14:48 [PATCH v4 00/23] powerpc/32: Implement C syscall entry/exit Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 01/23] powerpc/32s: Add missing call to kuep_lock on syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 02/23] powerpc/32: Always enable data translation " Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 03/23] powerpc/32: On syscall entry, enable instruction translation at the same time as data Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 04/23] powerpc/32: Reorder instructions to avoid using CTR in syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 05/23] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 06/23] powerpc/32s: Create C version of kuap_user/kernel_restore() and friends Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 07/23] powerpc/8xx: " Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 08/23] powerpc/irq: Add helper to set regs->softe Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 09/23] powerpc/irq: Rework helpers that manipulate MSR[EE/RI] Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 10/23] powerpc/irq: Add stub irq_soft_mask_return() for PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 11/23] powerpc/syscall: Rename syscall_64.c into syscall.c Christophe Leroy
2021-01-26 10:21 ` Nicholas Piggin
2021-01-26 10:28 ` David Laight
2021-01-27 23:50 ` Nicholas Piggin
2021-02-02 6:15 ` Christophe Leroy
2021-02-02 6:38 ` Nicholas Piggin
2021-02-02 6:58 ` Christophe Leroy
2021-02-02 20:10 ` Segher Boessenkool
2021-02-08 17:47 ` Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 12/23] powerpc/syscall: Make syscall.c buildable on PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 13/23] powerpc/syscall: Use is_compat_task() Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 14/23] powerpc/syscall: Save r3 in regs->orig_r3 Christophe Leroy
2021-01-26 10:18 ` Nicholas Piggin
2021-02-08 17:47 ` Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 15/23] powerpc/syscall: Change condition to check MSR_RI Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 16/23] powerpc/32: Always save non volatile GPRs at syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 17/23] powerpc/syscall: implement system call entry/exit logic in C for PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 18/23] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 19/23] powerpc/syscall: Avoid stack frame in likely part of system_call_exception() Christophe Leroy
2021-01-26 10:14 ` Nicholas Piggin
2021-01-25 14:48 ` [PATCH v4 20/23] powerpc/syscall: Do not check unsupported scv vector on PPC32 Christophe Leroy
2021-01-26 10:16 ` Nicholas Piggin
2021-02-08 17:45 ` Christophe Leroy
2021-01-25 14:48 ` Christophe Leroy [this message]
2021-01-25 14:48 ` [PATCH v4 22/23] powerpc/syscall: Optimise checks in beginning of system_call_exception() Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 23/23] powerpc/syscall: Avoid storing 'current' in another pointer Christophe Leroy
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