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
bus.c
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2020 Intel Corporation. All rights reserved. */
#include <linux/device.h>
#include <linux/module.h>

/**
 * DOC: cxl bus
 *
 * The CXL bus provides namespace for control devices and a rendezvous
 * point for cross-device interleave coordination.
 */
struct bus_type cxl_bus_type = {
	.name = "cxl",
};
EXPORT_SYMBOL_GPL(cxl_bus_type);

static __init int cxl_bus_init(void)
{
	return bus_register(&cxl_bus_type);
}

static void cxl_bus_exit(void)
{
	bus_unregister(&cxl_bus_type);
}

module_init(cxl_bus_init);
module_exit(cxl_bus_exit);
MODULE_LICENSE("GPL v2");
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