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Revision b90d72a6bfdb5e5c62cd223a8cdf4045bfbcb94d authored by Will Deacon on 12 January 2021, 22:18:55 UTC, committed by Catalin Marinas on 13 January 2021, 15:08:41 UTC 
Revert "arm64: Enable perf events based hard lockup detector"
 
This reverts commit 367c820ef08082e68df8a3bc12e62393af21e4b5.

lockup_detector_init() makes heavy use of per-cpu variables and must be
called with preemption disabled. Usually, it's handled early during boot
in kernel_init_freeable(), before SMP has been initialised.

Since we do not know whether or not our PMU interrupt can be signalled
as an NMI until considerably later in the boot process, the Arm PMU
driver attempts to re-initialise the lockup detector off the back of a
device_initcall(). Unfortunately, this is called from preemptible
context and results in the following splat:

  | BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
  | caller is debug_smp_processor_id+0x20/0x2c
  | CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.0+ #276
  | Hardware name: linux,dummy-virt (DT)
  | Call trace:
  |   dump_backtrace+0x0/0x3c0
  |   show_stack+0x20/0x6c
  |   dump_stack+0x2f0/0x42c
  |   check_preemption_disabled+0x1cc/0x1dc
  |   debug_smp_processor_id+0x20/0x2c
  |   hardlockup_detector_event_create+0x34/0x18c
  |   hardlockup_detector_perf_init+0x2c/0x134
  |   watchdog_nmi_probe+0x18/0x24
  |   lockup_detector_init+0x44/0xa8
  |   armv8_pmu_driver_init+0x54/0x78
  |   do_one_initcall+0x184/0x43c
  |   kernel_init_freeable+0x368/0x380
  |   kernel_init+0x1c/0x1cc
  |   ret_from_fork+0x10/0x30

Rather than bodge this with raw_smp_processor_id() or randomly disabling
preemption, simply revert the culprit for now until we figure out how to
do this properly.

Reported-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20201221162249.3119-1-lecopzer.chen@mediatek.com
Link: https://lore.kernel.org/r/20210112221855.10666-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
1 parent df06824
Raw File
ecc_curve_defs.h 
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _CRYTO_ECC_CURVE_DEFS_H
#define _CRYTO_ECC_CURVE_DEFS_H

/* NIST P-192: a = p - 3 */
static u64 nist_p192_g_x[] = { 0xF4FF0AFD82FF1012ull, 0x7CBF20EB43A18800ull,
				0x188DA80EB03090F6ull };
static u64 nist_p192_g_y[] = { 0x73F977A11E794811ull, 0x631011ED6B24CDD5ull,
				0x07192B95FFC8DA78ull };
static u64 nist_p192_p[] = { 0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFEull,
				0xFFFFFFFFFFFFFFFFull };
static u64 nist_p192_n[] = { 0x146BC9B1B4D22831ull, 0xFFFFFFFF99DEF836ull,
				0xFFFFFFFFFFFFFFFFull };
static u64 nist_p192_a[] = { 0xFFFFFFFFFFFFFFFCull, 0xFFFFFFFFFFFFFFFEull,
				0xFFFFFFFFFFFFFFFFull };
static u64 nist_p192_b[] = { 0xFEB8DEECC146B9B1ull, 0x0FA7E9AB72243049ull,
				0x64210519E59C80E7ull };
static struct ecc_curve nist_p192 = {
	.name = "nist_192",
	.g = {
		.x = nist_p192_g_x,
		.y = nist_p192_g_y,
		.ndigits = 3,
	},
	.p = nist_p192_p,
	.n = nist_p192_n,
	.a = nist_p192_a,
	.b = nist_p192_b
};

/* NIST P-256: a = p - 3 */
static u64 nist_p256_g_x[] = { 0xF4A13945D898C296ull, 0x77037D812DEB33A0ull,
				0xF8BCE6E563A440F2ull, 0x6B17D1F2E12C4247ull };
static u64 nist_p256_g_y[] = { 0xCBB6406837BF51F5ull, 0x2BCE33576B315ECEull,
				0x8EE7EB4A7C0F9E16ull, 0x4FE342E2FE1A7F9Bull };
static u64 nist_p256_p[] = { 0xFFFFFFFFFFFFFFFFull, 0x00000000FFFFFFFFull,
				0x0000000000000000ull, 0xFFFFFFFF00000001ull };
static u64 nist_p256_n[] = { 0xF3B9CAC2FC632551ull, 0xBCE6FAADA7179E84ull,
				0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFF00000000ull };
static u64 nist_p256_a[] = { 0xFFFFFFFFFFFFFFFCull, 0x00000000FFFFFFFFull,
				0x0000000000000000ull, 0xFFFFFFFF00000001ull };
static u64 nist_p256_b[] = { 0x3BCE3C3E27D2604Bull, 0x651D06B0CC53B0F6ull,
				0xB3EBBD55769886BCull, 0x5AC635D8AA3A93E7ull };
static struct ecc_curve nist_p256 = {
	.name = "nist_256",
	.g = {
		.x = nist_p256_g_x,
		.y = nist_p256_g_y,
		.ndigits = 4,
	},
	.p = nist_p256_p,
	.n = nist_p256_n,
	.a = nist_p256_a,
	.b = nist_p256_b
};

#endif
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