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Date:   Wed, 21 Nov 2018 22:14:39 +0300
From:   "Dmitry V. Levin" <ldv@altlinux.org>
To:     Paul Burton <paul.burton@mips.com>
Cc:     Elvira Khabirova <lineprinter@altlinux.org>,
        Ralf Baechle <ralf@linux-mips.org>,
        James Hogan <jhogan@kernel.org>, linux-mips@linux-mips.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] mips: fix mips_get_syscall_arg o32 check
Message-ID: <20181121191438.GB10301@altlinux.org>
References: <20181107042751.3b519062@akathisia>
 <CALCETrV1v-DPRfDRwiH=xn29bxWxiHdZtAH1nw=dsmDtnT0YGQ@mail.gmail.com>
 <20181120001128.GA11300@altlinux.org>
 <20181121004422.GA29053@altlinux.org>
 <20181121184004.jro532jopnbmru2m@pburton-laptop>
 <20181121190009.GA10301@altlinux.org>
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When checking for TIF_32BIT_REGS flag, mips_get_syscall_arg() should
use the task specified as its argument instead of the current task.

This potentially affects all syscall_get_arguments() users
who specify tasks different from the current.

Fixes: c0ff3c53d4f99 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
 arch/mips/include/asm/syscall.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index 0170602a1e4e..6cf8ffb5367e 100644
--- a/arch/mips/include/asm/syscall.h
+++ b/arch/mips/include/asm/syscall.h
@@ -73,7 +73,7 @@ static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
 #ifdef CONFIG_64BIT
 	case 4: case 5: case 6: case 7:
 #ifdef CONFIG_MIPS32_O32
-		if (test_thread_flag(TIF_32BIT_REGS))
+		if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
 			return get_user(*arg, (int *)usp + n);
 		else
 #endif
-- 
ldv