[PATCH v2 3/4] powerpc: trap_is_syscall() helper to hide syscall trap number

[Michael Ellerman]

From: Nicholas Piggin <npig...@gmail.com>

A new system call interrupt will be added with a new trap number.
Hide the explicit 0xc00 test behind an accessor to reduce churn
in callers.

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
[mpe: Make it a static inline]
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
 arch/powerpc/include/asm/ptrace.h  | 5 +++++
 arch/powerpc/include/asm/syscall.h | 5 ++++-
 arch/powerpc/kernel/process.c      | 2 +-
 arch/powerpc/kernel/signal.c       | 2 +-
 arch/powerpc/xmon/xmon.c           | 2 +-
 5 files changed, 12 insertions(+), 4 deletions(-)

v2: mpe: Make it a static inline

diff --git a/arch/powerpc/include/asm/ptrace.h 
b/arch/powerpc/include/asm/ptrace.h
index 7c585bddc06e..5db45790a087 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -222,6 +222,11 @@ static inline void set_trap(struct pt_regs *regs, unsigned 
long val)
        regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK);
 }
 
+static inline bool trap_is_syscall(struct pt_regs *regs)
+{
+       return TRAP(regs) == 0xc00;
+}
+
 #define arch_has_single_step() (1)
 #ifndef CONFIG_BOOK3S_601
 #define arch_has_block_step()  (true)
diff --git a/arch/powerpc/include/asm/syscall.h 
b/arch/powerpc/include/asm/syscall.h
index 38d62acfdce7..fd1b518eed17 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -26,7 +26,10 @@ static inline int syscall_get_nr(struct task_struct *task, 
struct pt_regs *regs)
         * This is important for seccomp so that compat tasks can set r0 = -1
         * to reject the syscall.
         */
-       return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1;
+       if (trap_is_syscall(regs))
+               return regs->gpr[0];
+       else
+               return -1;
 }
 
 static inline void syscall_rollback(struct task_struct *task,
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 8af3583546b7..db766252238f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1413,7 +1413,7 @@ void show_regs(struct pt_regs * regs)
        print_msr_bits(regs->msr);
        pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
        trap = TRAP(regs);
-       if ((TRAP(regs) != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
+       if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR))
                pr_cont("CFAR: "REG" ", regs->orig_gpr3);
        if (trap == 0x200 || trap == 0x300 || trap == 0x600)
 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a264989626fd..f2be9e960c2e 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -198,7 +198,7 @@ static void check_syscall_restart(struct pt_regs *regs, 
struct k_sigaction *ka,
        int restart = 1;
 
        /* syscall ? */
-       if (TRAP(regs) != 0x0C00)
+       if (!trap_is_syscall(regs))
                return;
 
        /* error signalled ? */
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 92761e47fb5c..a7430632bab4 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1776,7 +1776,7 @@ static void prregs(struct pt_regs *fp)
 #endif
        printf("pc  = ");
        xmon_print_symbol(fp->nip, " ", "\n");
-       if (TRAP(fp) != 0xc00 && cpu_has_feature(CPU_FTR_CFAR)) {
+       if (!trap_is_syscall(fp) && cpu_has_feature(CPU_FTR_CFAR)) {
                printf("cfar= ");
                xmon_print_symbol(fp->orig_gpr3, " ", "\n");
        }
-- 
2.25.1