[PATCH v7 16/22] powerpc: define syscall_get_error()

Dmitry V. Levin ldv at altlinux.org
Fri Mar 1 06:39:31 AEDT 2019

syscall_get_error() is required to be implemented on this
architecture in addition to already implemented syscall_get_nr(),
syscall_get_arguments(), syscall_get_return_value(), and
syscall_get_arch() functions in order to extend the generic
ptrace API with PTRACE_GET_SYSCALL_INFO request.

Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Oleg Nesterov <oleg at redhat.com>
Cc: Andy Lutomirski <luto at kernel.org>
Cc: Elvira Khabirova <lineprinter at altlinux.org>
Cc: Eugene Syromyatnikov <esyr at redhat.com>
Cc: linuxppc-dev at lists.ozlabs.org
Signed-off-by: Dmitry V. Levin <ldv at altlinux.org>

This is just a gentle ping, the patch is unchanged.

    v7: unchanged
    v6: unchanged
    This change has been tested with
    tools/testing/selftests/ptrace/get_syscall_info.c and strace,
    so it's correct from PTRACE_GET_SYSCALL_INFO point of view.
    This cast doubts on commit v4.3-rc1~86^2~81 that changed
    syscall_set_return_value() in a way that doesn't quite match
    syscall_get_error(), but syscall_set_return_value() is out
    of scope of this series, so I'll just let you know my concerns.

 arch/powerpc/include/asm/syscall.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index 1a0e7a8b1c81..b522781ad7c0 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -38,6 +38,16 @@ static inline void syscall_rollback(struct task_struct *task,
 	regs->gpr[3] = regs->orig_gpr3;
+static inline long syscall_get_error(struct task_struct *task,
+				     struct pt_regs *regs)
+	/*
+	 * If the system call failed,
+	 * regs->gpr[3] contains a positive ERRORCODE.
+	 */
+	return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
 static inline long syscall_get_return_value(struct task_struct *task,
 					    struct pt_regs *regs)

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