https://github.com/torvalds/linux
Revision 4f74d72aa7067e75af92fbab077e6d7d0210be66 authored by Mark Rutland on 18 May 2018, 14:08:41 UTC, committed by Ingo Molnar on 19 May 2018, 06:07:56 UTC
When CONFIG_RANDOMIZE_TEXT_OFFSET=y, TEXT_OFFSET is an arbitrary
multiple of PAGE_SIZE in the interval [0, 2MB).

The EFI stub does not account for the potential misalignment of
TEXT_OFFSET relative to EFI_KIMG_ALIGN, and produces a randomized
physical offset which is always a round multiple of EFI_KIMG_ALIGN.
This may result in statically allocated objects whose alignment exceeds
PAGE_SIZE to appear misaligned in memory. This has been observed to
result in spurious stack overflow reports and failure to make use of
the IRQ stacks, and theoretically could result in a number of other
issues.

We can OR in the low bits of TEXT_OFFSET to ensure that we have the
necessary offset (and hence preserve the misalignment of TEXT_OFFSET
relative to EFI_KIMG_ALIGN), so let's do that.

Reported-by: Kim Phillips <kim.phillips@arm.com>
Tested-by: Kim Phillips <kim.phillips@arm.com>
[ardb: clarify comment and commit log, drop unneeded parens]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 6f26b3671184c36d ("arm64: kaslr: increase randomization granularity")
Link: http://lkml.kernel.org/r/20180518140841.9731-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent 0b3225a
Raw File
Tip revision: 4f74d72aa7067e75af92fbab077e6d7d0210be66 authored by Mark Rutland on 18 May 2018, 14:08:41 UTC
efi/libstub/arm64: Handle randomized TEXT_OFFSET
Tip revision: 4f74d72
trace.h
/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM dccp

#if !defined(_TRACE_DCCP_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_DCCP_H

#include <net/sock.h>
#include "dccp.h"
#include "ccids/ccid3.h"
#include <linux/tracepoint.h>
#include <trace/events/net_probe_common.h>

TRACE_EVENT(dccp_probe,

	TP_PROTO(struct sock *sk, size_t size),

	TP_ARGS(sk, size),

	TP_STRUCT__entry(
		/* sockaddr_in6 is always bigger than sockaddr_in */
		__array(__u8, saddr, sizeof(struct sockaddr_in6))
		__array(__u8, daddr, sizeof(struct sockaddr_in6))
		__field(__u16, sport)
		__field(__u16, dport)
		__field(__u16, size)
		__field(__u16, tx_s)
		__field(__u32, tx_rtt)
		__field(__u32, tx_p)
		__field(__u32, tx_x_calc)
		__field(__u64, tx_x_recv)
		__field(__u64, tx_x)
		__field(__u32, tx_t_ipi)
	),

	TP_fast_assign(
		const struct inet_sock *inet = inet_sk(sk);
		struct ccid3_hc_tx_sock *hc = NULL;

		if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
			hc = ccid3_hc_tx_sk(sk);

		memset(__entry->saddr, 0, sizeof(struct sockaddr_in6));
		memset(__entry->daddr, 0, sizeof(struct sockaddr_in6));

		TP_STORE_ADDR_PORTS(__entry, inet, sk);

		/* For filtering use */
		__entry->sport = ntohs(inet->inet_sport);
		__entry->dport = ntohs(inet->inet_dport);

		__entry->size = size;
		if (hc) {
			__entry->tx_s = hc->tx_s;
			__entry->tx_rtt = hc->tx_rtt;
			__entry->tx_p = hc->tx_p;
			__entry->tx_x_calc = hc->tx_x_calc;
			__entry->tx_x_recv = hc->tx_x_recv >> 6;
			__entry->tx_x = hc->tx_x >> 6;
			__entry->tx_t_ipi = hc->tx_t_ipi;
		} else {
			__entry->tx_s = 0;
			memset(&__entry->tx_rtt, 0, (void *)&__entry->tx_t_ipi -
			       (void *)&__entry->tx_rtt +
			       sizeof(__entry->tx_t_ipi));
		}
	),

	TP_printk("src=%pISpc dest=%pISpc size=%d tx_s=%d tx_rtt=%d "
		  "tx_p=%d tx_x_calc=%u tx_x_recv=%llu tx_x=%llu tx_t_ipi=%d",
		  __entry->saddr, __entry->daddr, __entry->size,
		  __entry->tx_s, __entry->tx_rtt, __entry->tx_p,
		  __entry->tx_x_calc, __entry->tx_x_recv, __entry->tx_x,
		  __entry->tx_t_ipi)
);

#endif /* _TRACE_TCP_H */

/* This part must be outside protection */
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH .
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_FILE trace
#include <trace/define_trace.h>
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