Revision be65e2595b4c1fbeceba336d8ee83406726b1d8d authored by Linus Torvalds on 06 September 2018, 16:06:49 UTC, committed by Linus Torvalds on 06 September 2018, 16:06:49 UTC
Pull tracing fixes from Steven Rostedt:
"This fixes two annoying bugs:
- The first one is a side effect caused by using SRCU for rcuidle
tracepoints. It seems that the perf was depending on the rcuidle
tracepoints to make RCU watch when it wasn't.
The real fix will be to have perf use SRCU instead of depending on
RCU watching, but that can't be done until SRCU is safe to use in
NMI context (Paul's working on that).
- The second bug fix is for a bug that's been periodically making my
tests fail randomly for some time. I haven't had time to track it
down, but finally have. It has to do with stressing NMIs (via perf)
while enabling or disabling ftrace function handling with lockdep
enabled.
If an interrupt happens and just as it returns, it sets lockdep
back to "interrupts enabled" but before it returns an NMI is
triggered, and if this happens while printk_nmi_enter has a
breakpoint attached to it (because ftrace is converting it to or
from nop to call fentry), the breakpoint trap also calls into
lockdep, and since returning from the NMI to a interrupt handler,
interrupts were disabled when the NMI went off, lockdep keeps its
state as interrupts disabled when it returns back from the
interrupt handler where interrupts are enabled.
This causes lockdep_assert_irqs_enabled() to trigger a false
positive"
* tag 'trace-v4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
printk/tracing: Do not trace printk_nmi_enter()
tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle tracepoints
ptp_classifier.c
/* PTP classifier
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
/* The below program is the bpf_asm (tools/net/) representation of
* the opcode array in the ptp_filter structure.
*
* For convenience, this can easily be altered and reviewed with
* bpf_asm and bpf_dbg, e.g. `./bpf_asm -c prog` where prog is a
* simple file containing the below program:
*
* ldh [12] ; load ethertype
*
* ; PTP over UDP over IPv4 over Ethernet
* test_ipv4:
* jneq #0x800, test_ipv6 ; ETH_P_IP ?
* ldb [23] ; load proto
* jneq #17, drop_ipv4 ; IPPROTO_UDP ?
* ldh [20] ; load frag offset field
* jset #0x1fff, drop_ipv4 ; don't allow fragments
* ldxb 4*([14]&0xf) ; load IP header len
* ldh [x + 16] ; load UDP dst port
* jneq #319, drop_ipv4 ; is port PTP_EV_PORT ?
* ldh [x + 22] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x10 ; PTP_CLASS_IPV4
* ret a ; return PTP class
* drop_ipv4: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over UDP over IPv6 over Ethernet
* test_ipv6:
* jneq #0x86dd, test_8021q ; ETH_P_IPV6 ?
* ldb [20] ; load proto
* jneq #17, drop_ipv6 ; IPPROTO_UDP ?
* ldh [56] ; load UDP dst port
* jneq #319, drop_ipv6 ; is port PTP_EV_PORT ?
* ldh [62] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x20 ; PTP_CLASS_IPV6
* ret a ; return PTP class
* drop_ipv6: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over 802.1Q over Ethernet
* test_8021q:
* jneq #0x8100, test_ieee1588 ; ETH_P_8021Q ?
* ldh [16] ; load inner type
* jneq #0x88f7, test_8021q_ipv4 ; ETH_P_1588 ?
* ldb [18] ; load payload
* and #0x8 ; as we don't have ports here, test
* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
* ldh [18] ; reload payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0xc0 ; PTP_CLASS_VLAN|PTP_CLASS_L2
* ret a ; return PTP class
*
* ; PTP over UDP over IPv4 over 802.1Q over Ethernet
* test_8021q_ipv4:
* jneq #0x800, test_8021q_ipv6 ; ETH_P_IP ?
* ldb [27] ; load proto
* jneq #17, drop_8021q_ipv4 ; IPPROTO_UDP ?
* ldh [24] ; load frag offset field
* jset #0x1fff, drop_8021q_ipv4; don't allow fragments
* ldxb 4*([18]&0xf) ; load IP header len
* ldh [x + 20] ; load UDP dst port
* jneq #319, drop_8021q_ipv4 ; is port PTP_EV_PORT ?
* ldh [x + 26] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x90 ; PTP_CLASS_VLAN|PTP_CLASS_IPV4
* ret a ; return PTP class
* drop_8021q_ipv4: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over UDP over IPv6 over 802.1Q over Ethernet
* test_8021q_ipv6:
* jneq #0x86dd, drop_8021q_ipv6 ; ETH_P_IPV6 ?
* ldb [24] ; load proto
* jneq #17, drop_8021q_ipv6 ; IPPROTO_UDP ?
* ldh [60] ; load UDP dst port
* jneq #319, drop_8021q_ipv6 ; is port PTP_EV_PORT ?
* ldh [66] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0xa0 ; PTP_CLASS_VLAN|PTP_CLASS_IPV6
* ret a ; return PTP class
* drop_8021q_ipv6: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over Ethernet
* test_ieee1588:
* jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
* ldb [14] ; load payload
* and #0x8 ; as we don't have ports here, test
* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
* ldh [14] ; reload payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x40 ; PTP_CLASS_L2
* ret a ; return PTP class
* drop_ieee1588: ret #0x0 ; PTP_CLASS_NONE
*/
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/ptp_classify.h>
static struct bpf_prog *ptp_insns __read_mostly;
unsigned int ptp_classify_raw(const struct sk_buff *skb)
{
return BPF_PROG_RUN(ptp_insns, skb);
}
EXPORT_SYMBOL_GPL(ptp_classify_raw);
void __init ptp_classifier_init(void)
{
static struct sock_filter ptp_filter[] __initdata = {
{ 0x28, 0, 0, 0x0000000c },
{ 0x15, 0, 12, 0x00000800 },
{ 0x30, 0, 0, 0x00000017 },
{ 0x15, 0, 9, 0x00000011 },
{ 0x28, 0, 0, 0x00000014 },
{ 0x45, 7, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x0000000e },
{ 0x48, 0, 0, 0x00000010 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x48, 0, 0, 0x00000016 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000010 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 9, 0x000086dd },
{ 0x30, 0, 0, 0x00000014 },
{ 0x15, 0, 6, 0x00000011 },
{ 0x28, 0, 0, 0x00000038 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x28, 0, 0, 0x0000003e },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000020 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 32, 0x00008100 },
{ 0x28, 0, 0, 0x00000010 },
{ 0x15, 0, 7, 0x000088f7 },
{ 0x30, 0, 0, 0x00000012 },
{ 0x54, 0, 0, 0x00000008 },
{ 0x15, 0, 35, 0x00000000 },
{ 0x28, 0, 0, 0x00000012 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x000000c0 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x15, 0, 12, 0x00000800 },
{ 0x30, 0, 0, 0x0000001b },
{ 0x15, 0, 9, 0x00000011 },
{ 0x28, 0, 0, 0x00000018 },
{ 0x45, 7, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x00000012 },
{ 0x48, 0, 0, 0x00000014 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x48, 0, 0, 0x0000001a },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000090 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 8, 0x000086dd },
{ 0x30, 0, 0, 0x00000018 },
{ 0x15, 0, 6, 0x00000011 },
{ 0x28, 0, 0, 0x0000003c },
{ 0x15, 0, 4, 0x0000013f },
{ 0x28, 0, 0, 0x00000042 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x000000a0 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 7, 0x000088f7 },
{ 0x30, 0, 0, 0x0000000e },
{ 0x54, 0, 0, 0x00000008 },
{ 0x15, 0, 4, 0x00000000 },
{ 0x28, 0, 0, 0x0000000e },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000040 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
};
struct sock_fprog_kern ptp_prog = {
.len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter,
};
BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog));
}
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