Revision 61bf318eac2c13356f7bd1c6a05421ef504ccc8a authored by Sergei Trofimovich on 13 March 2021, 05:08:27 UTC, committed by Linus Torvalds on 13 March 2021, 19:27:31 UTC
In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not return error sign properly.

The bug is in mismatch between get/set errors:

static inline long syscall_get_error(struct task_struct *task,
                                     struct pt_regs *regs)
{
        return regs->r10 == -1 ? regs->r8:0;
}

static inline long syscall_get_return_value(struct task_struct *task,
                                            struct pt_regs *regs)
{
        return regs->r8;
}

static inline void syscall_set_return_value(struct task_struct *task,
                                            struct pt_regs *regs,
                                            int error, long val)
{
        if (error) {
                /* error < 0, but ia64 uses > 0 return value */
                regs->r8 = -error;
                regs->r10 = -1;
        } else {
                regs->r8 = val;
                regs->r10 = 0;
        }
}

Tested on v5.10 on rx3600 machine (ia64 9040 CPU).

Link: https://lkml.kernel.org/r/20210221002554.333076-2-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 0ceb1ac
Raw File
gntdev-dmabuf.h
/* SPDX-License-Identifier: GPL-2.0 */

/*
 * Xen dma-buf functionality for gntdev.
 *
 * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
 */

#ifndef _GNTDEV_DMABUF_H
#define _GNTDEV_DMABUF_H

#include <xen/gntdev.h>

struct gntdev_dmabuf_priv;
struct gntdev_priv;

struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp);

void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv);

long gntdev_ioctl_dmabuf_exp_from_refs(struct gntdev_priv *priv, int use_ptemod,
				       struct ioctl_gntdev_dmabuf_exp_from_refs __user *u);

long gntdev_ioctl_dmabuf_exp_wait_released(struct gntdev_priv *priv,
					   struct ioctl_gntdev_dmabuf_exp_wait_released __user *u);

long gntdev_ioctl_dmabuf_imp_to_refs(struct gntdev_priv *priv,
				     struct ioctl_gntdev_dmabuf_imp_to_refs __user *u);

long gntdev_ioctl_dmabuf_imp_release(struct gntdev_priv *priv,
				     struct ioctl_gntdev_dmabuf_imp_release __user *u);

#endif
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