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Revision 66cb3a2d7ad0d0e9af4d3430a4f2a32ffb9ac098 authored by David Arcari on 26 May 2022, 20:31:40 UTC, committed by Hans de Goede on 10 June 2022, 19:59:08 UTC 
platform/x86/intel: Fix pmt_crashlog array reference
 
The probe function pmt_crashlog_probe() may incorrectly reference
the 'priv->entry array' as it uses 'i' to reference the array instead
of 'priv->num_entries' as it should.  This is similar to the problem
that was addressed in pmt_telemetry_probe via commit 2cdfa0c20d58
("platform/x86/intel: Fix 'rmmod pmt_telemetry' panic").

Cc: "David E. Box" <david.e.box@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mark Gross <markgross@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David Arcari <darcari@redhat.com>
Reviewed-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20220526203140.339120-1-darcari@redhat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
1 parent b9c29f3
Raw File
tracex4_kern.c 
/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>

struct pair {
	u64 val;
	u64 ip;
};

struct {
	__uint(type, BPF_MAP_TYPE_HASH);
	__type(key, long);
	__type(value, struct pair);
	__uint(max_entries, 1000000);
} my_map SEC(".maps");

/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
 * example will no longer be meaningful
 */
SEC("kprobe/kmem_cache_free")
int bpf_prog1(struct pt_regs *ctx)
{
	long ptr = PT_REGS_PARM2(ctx);

	bpf_map_delete_elem(&my_map, &ptr);
	return 0;
}

SEC("kretprobe/kmem_cache_alloc_node")
int bpf_prog2(struct pt_regs *ctx)
{
	long ptr = PT_REGS_RC(ctx);
	long ip = 0;

	/* get ip address of kmem_cache_alloc_node() caller */
	BPF_KRETPROBE_READ_RET_IP(ip, ctx);

	struct pair v = {
		.val = bpf_ktime_get_ns(),
		.ip = ip,
	};

	bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
	return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
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