https://github.com/torvalds/linux
Revision 573b3aa6940661dc50c383213d428c27df78be7c authored by Yonghong Song on 30 July 2018, 15:49:03 UTC, committed by Daniel Borkmann on 30 July 2018, 22:37:09 UTC
I hit the following problem when I tried to use bpftool to dump a percpu array. $ sudo ./bpftool map show 61: percpu_array name stub flags 0x0 key 4B value 4B max_entries 1 memlock 4096B ... $ sudo ./bpftool map dump id 61 bpftool: malloc.c:2406: sysmalloc: Assertion `(old_top == initial_top (av) && old_size == 0) || \ ((unsigned long) (old_size) >= MINSIZE && \ prev_inuse (old_top) && \ ((unsigned long) old_end & (pagesize - 1)) == 0)' failed. Aborted Further debugging revealed that this is due to miscommunication between bpftool and kernel. For example, for the above percpu_array with value size of 4B. The map info returned to user space has value size of 4B. In bpftool, the values array for lookup is allocated like: info->value_size * get_possible_cpus() = 4 * get_possible_cpus() In kernel (kernel/bpf/syscall.c), the values array size is rounded up to multiple of 8. round_up(map->value_size, 8) * num_possible_cpus() = 8 * num_possible_cpus() So when kernel copies the values to user buffer, the kernel will overwrite beyond user buffer boundary. This patch fixed the issue by allocating and stepping through percpu map value array properly in bpftool. Fixes: 71bb428fe2c19 ("tools: bpf: add bpftool") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1 parent 61f4b23
Tip revision: 573b3aa6940661dc50c383213d428c27df78be7c authored by Yonghong Song on 30 July 2018, 15:49:03 UTC
tools/bpftool: fix a percpu_array map dump problem
tools/bpftool: fix a percpu_array map dump problem
Tip revision: 573b3aa
acpi_io.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ACPI_IO_H_
#define _ACPI_IO_H_
#include <linux/io.h>
#include <asm/acpi.h>
#ifndef acpi_os_ioremap
static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
acpi_size size)
{
return ioremap_cache(phys, size);
}
#endif
extern bool acpi_permanent_mmap;
void __iomem *__ref
acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
int acpi_os_map_generic_address(struct acpi_generic_address *addr);
void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
#endif
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