[PATCH v5 17/22] powerpc/syscall: Do not check unsupported scv vector on PPC32
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STALE2042d
From: Christophe Leroy <hidden>
Date: 2021-02-08 16:38:27
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), ptrace support, the rest · Maintainers:
Madhavan Srinivasan, Oleg Nesterov, Linus Torvalds
Only PPC64 has scv. No need to check the 0x7ff0 trap on PPC32. For that, add a helper trap_is_unsupported_scv() similar to trap_is_scv(). And ignore the scv parameter in syscall_exit_prepare (Save 14 cycles 346 => 332 cycles) Signed-off-by: Christophe Leroy <redacted> --- v5: Added a helper trap_is_unsupported_scv() --- arch/powerpc/include/asm/ptrace.h | 5 +++++ arch/powerpc/kernel/entry_32.S | 1 - arch/powerpc/kernel/interrupt.c | 7 +++++-- 3 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 58f9dc060a7b..2c842b11a924 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h@@ -229,6 +229,11 @@ static inline bool trap_is_scv(struct pt_regs *regs) return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); } +static inline bool trap_is_unsupported_scv(struct pt_regs *regs) +{ + return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0); +} + static inline bool trap_is_syscall(struct pt_regs *regs) { return (trap_is_scv(regs) || TRAP(regs) == 0xc00);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index cffe58e63356..7c824e8928d0 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S@@ -344,7 +344,6 @@ transfer_to_syscall: ret_from_syscall: addi r4,r1,STACK_FRAME_OVERHEAD - li r5,0 bl syscall_exit_prepare #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) /* If the process has its own DBCR0 value, load it up. The internal
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 205902052112..8fafca727b8b 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c@@ -88,7 +88,7 @@ notrace long system_call_exception(long r3, long r4, long r5, local_irq_enable(); if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) { - if (unlikely(regs->trap == 0x7ff0)) { + if (unlikely(trap_is_unsupported_scv(regs))) { /* Unsupported scv vector */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return regs->gpr[3];
@@ -111,7 +111,7 @@ notrace long system_call_exception(long r3, long r4, long r5, r8 = regs->gpr[8]; } else if (unlikely(r0 >= NR_syscalls)) { - if (unlikely(regs->trap == 0x7ff0)) { + if (unlikely(trap_is_unsupported_scv(regs))) { /* Unsupported scv vector */ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); return regs->gpr[3];
@@ -224,6 +224,9 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, unsigned long ti_flags; unsigned long ret = 0; + if (IS_ENABLED(CONFIG_PPC32)) + scv = 0; + CT_WARN_ON(ct_state() == CONTEXT_USER); #ifdef CONFIG_PPC64
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2.25.0