Re: [PATCH] perf: fix panic by disable ftrace on fault.c
From: 王贇
Date: Mon Sep 13 2021 - 21:52:37 EST
Hi, Dave, Peter
Nice to have you guys digging the root cause, please allow me to paste whole
trace and the way of reproduce here firstly before checking the details:
Below is the full trace, triggered with the latest linux-next master branch:
[ 58.999453][ C0] traps: PANIC: double fault, error_code: 0x0
[ 58.999472][ C0] double fault: 0000 [#1] SMP PTI
[ 58.999478][ C0] CPU: 0 PID: 799 Comm: a.out Not tainted 5.14.0+ #107
[ 58.999485][ C0] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 58.999488][ C0] RIP: 0010:perf_swevent_get_recursion_context+0x0/0x70
[ 58.999505][ C0] Code: 48 03 43 28 48 8b 0c 24 bb 01 00 00 00 4c 29 f0 48 39 c8 48 0f 47 c1 49 89 45 08 e9 48 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 <55> 53 e8 89 18 f2 ff 48 c7 c2 20 4d 03 00 65 48 03 15 5a 34 d2 7e
[ 58.999511][ C0] RSP: 0018:fffffe000000b000 EFLAGS: 00010046
[ 58.999517][ C0] RAX: 0000000080120005 RBX: fffffe000000b050 RCX: 0000000000000000
[ 58.999522][ C0] RDX: ffff888106f5a180 RSI: ffffffff812696d1 RDI: 000000000000001c
[ 58.999526][ C0] RBP: 000000000000001c R08: 0000000000000001 R09: 0000000000000000
[ 58.999530][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 58.999533][ C0] R13: fffffe000000b044 R14: 0000000000000001 R15: 0000000000000001
[ 58.999537][ C0] FS: 00007f21fc62c740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
[ 58.999543][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 58.999547][ C0] CR2: fffffe000000aff8 CR3: 0000000106e2e001 CR4: 00000000003606f0
[ 58.999551][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 58.999555][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 58.999559][ C0] Call Trace:
[ 58.999562][ C0] <NMI>
[ 58.999565][ C0] perf_trace_buf_alloc+0x26/0xd0
[ 58.999579][ C0] ? is_prefetch.isra.25+0x260/0x260
[ 58.999586][ C0] ? __bad_area_nosemaphore+0x1b8/0x280
[ 58.999592][ C0] perf_ftrace_function_call+0x18f/0x2e0
[ 58.999604][ C0] ? perf_trace_buf_alloc+0xbf/0xd0
[ 58.999642][ C0] ? 0xffffffffa00ba083
[ 58.999669][ C0] 0xffffffffa00ba083
[ 58.999688][ C0] ? 0xffffffffa00ba083
[ 58.999708][ C0] ? kernelmode_fixup_or_oops+0x5/0x120
[ 58.999721][ C0] kernelmode_fixup_or_oops+0x5/0x120
[ 58.999728][ C0] __bad_area_nosemaphore+0x1b8/0x280
[ 58.999747][ C0] do_user_addr_fault+0x410/0x920
[ 58.999763][ C0] ? 0xffffffffa00ba083
[ 58.999780][ C0] exc_page_fault+0x92/0x300
[ 58.999796][ C0] asm_exc_page_fault+0x1e/0x30
[ 58.999805][ C0] RIP: 0010:__get_user_nocheck_8+0x6/0x13
[ 58.999814][ C0] Code: 01 ca c3 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 8b 10 31 c0 0f 01 ca c3 66 90 0f 01 cb 0f ae e8 <48> 8b 10 31 c0 0f 01 ca c3 90 0f 01 ca 31 d2 48 c7 c0 f2 ff ff ff
[ 58.999819][ C0] RSP: 0018:fffffe000000b370 EFLAGS: 00050046
[ 58.999825][ C0] RAX: 0000000000000000 RBX: fffffe000000b3d0 RCX: 0000000000000000
[ 58.999828][ C0] RDX: ffff888106f5a180 RSI: ffffffff8100a91e RDI: fffffe000000b3d0
[ 58.999832][ C0] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[ 58.999836][ C0] R10: 0000000000000000 R11: 0000000000000014 R12: 00007fffffffeff0
[ 58.999839][ C0] R13: ffff888106f5a180 R14: 000000000000007f R15: 000000000000007f
[ 58.999867][ C0] ? perf_callchain_user+0x25e/0x2f0
[ 58.999886][ C0] perf_callchain_user+0x266/0x2f0
[ 58.999907][ C0] get_perf_callchain+0x194/0x210
[ 58.999938][ C0] perf_callchain+0xa3/0xc0
[ 58.999956][ C0] perf_prepare_sample+0xa5/0xa60
[ 58.999984][ C0] perf_event_output_forward+0x7b/0x1b0
[ 58.999996][ C0] ? perf_swevent_get_recursion_context+0x62/0x70
[ 59.000008][ C0] ? perf_trace_buf_alloc+0xbf/0xd0
[ 59.000026][ C0] __perf_event_overflow+0x67/0x120
[ 59.000042][ C0] perf_swevent_overflow+0xcb/0x110
[ 59.000065][ C0] perf_swevent_event+0xb0/0xf0
[ 59.000078][ C0] perf_tp_event+0x292/0x410
[ 59.000085][ C0] ? 0xffffffffa00ba083
[ 59.000120][ C0] ? tracing_gen_ctx_irq_test+0x8f/0xa0
[ 59.000129][ C0] ? perf_swevent_event+0x28/0xf0
[ 59.000142][ C0] ? perf_tp_event+0x2d7/0x410
[ 59.000150][ C0] ? tracing_gen_ctx_irq_test+0x8f/0xa0
[ 59.000157][ C0] ? perf_swevent_event+0x28/0xf0
[ 59.000171][ C0] ? perf_tp_event+0x2d7/0x410
[ 59.000179][ C0] ? tracing_gen_ctx_irq_test+0x8f/0xa0
[ 59.000198][ C0] ? tracing_gen_ctx_irq_test+0x8f/0xa0
[ 59.000206][ C0] ? perf_swevent_event+0x28/0xf0
[ 59.000233][ C0] ? perf_trace_run_bpf_submit+0x87/0xc0
[ 59.000244][ C0] ? perf_trace_buf_alloc+0x86/0xd0
[ 59.000250][ C0] perf_trace_run_bpf_submit+0x87/0xc0
[ 59.000276][ C0] perf_trace_lock_acquire+0x12b/0x170
[ 59.000308][ C0] lock_acquire+0x1bf/0x2e0
[ 59.000317][ C0] ? perf_output_begin+0x5/0x4b0
[ 59.000348][ C0] perf_output_begin+0x70/0x4b0
[ 59.000356][ C0] ? perf_output_begin+0x5/0x4b0
[ 59.000394][ C0] perf_log_throttle+0xe2/0x1a0
[ 59.000431][ C0] ? 0xffffffffa00ba083
[ 59.000447][ C0] ? perf_event_update_userpage+0x135/0x2d0
[ 59.000462][ C0] ? 0xffffffffa00ba083
[ 59.000471][ C0] ? 0xffffffffa00ba083
[ 59.000495][ C0] ? perf_event_update_userpage+0x135/0x2d0
[ 59.000506][ C0] ? rcu_read_lock_held_common+0x5/0x40
[ 59.000519][ C0] ? rcu_read_lock_held_common+0xe/0x40
[ 59.000528][ C0] ? rcu_read_lock_sched_held+0x23/0x80
[ 59.000539][ C0] ? lock_release+0xc7/0x2b0
[ 59.000560][ C0] ? __perf_event_account_interrupt+0x116/0x160
[ 59.000576][ C0] __perf_event_account_interrupt+0x116/0x160
[ 59.000589][ C0] __perf_event_overflow+0x3e/0x120
[ 59.000604][ C0] handle_pmi_common+0x30f/0x400
[ 59.000611][ C0] ? perf_ftrace_function_call+0x268/0x2e0
[ 59.000620][ C0] ? perf_ftrace_function_call+0x53/0x2e0
[ 59.000663][ C0] ? 0xffffffffa00ba083
[ 59.000689][ C0] ? 0xffffffffa00ba083
[ 59.000729][ C0] ? intel_pmu_handle_irq+0x120/0x620
[ 59.000737][ C0] ? handle_pmi_common+0x5/0x400
[ 59.000743][ C0] intel_pmu_handle_irq+0x120/0x620
[ 59.000767][ C0] perf_event_nmi_handler+0x30/0x50
[ 59.000779][ C0] nmi_handle+0xba/0x2a0
[ 59.000806][ C0] default_do_nmi+0x45/0xf0
[ 59.000819][ C0] exc_nmi+0x155/0x170
[ 59.000838][ C0] end_repeat_nmi+0x16/0x55
[ 59.000845][ C0] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60
[ 59.000853][ C0] Code: 00 75 10 65 48 8b 04 25 c0 71 01 00 48 8b 80 88 15 00 00 f3 c3 0f 1f 84 00 00 00 00 00 65 8b 05 09 77 e0 7e 89 c1 48 8b 34 24 <65> 48 8b 14 25 c0 71 01 00 81 e1 00 01 00 00 a9 00 01 ff 00 74 10
[ 59.000858][ C0] RSP: 0000:ffffc90000003dd0 EFLAGS: 00000046
[ 59.000863][ C0] RAX: 0000000080010001 RBX: ffffffff82a1db40 RCX: 0000000080010001
[ 59.000867][ C0] RDX: ffff888106f5a180 RSI: ffffffff81009613 RDI: 0000000000000000
[ 59.000871][ C0] RBP: ffff88813bc40d08 R08: ffff888106f5abb8 R09: 00000000fffffffe
[ 59.000875][ C0] R10: ffffc90000003be0 R11: 00000000ffd17b4b R12: ffff88813bc118a0
[ 59.000878][ C0] R13: ffff88813bc40c00 R14: 0000000000000000 R15: ffffffff82a1db40
[ 59.000906][ C0] ? x86_pmu_enable+0x383/0x440
[ 59.000924][ C0] ? __sanitizer_cov_trace_pc+0xd/0x60
[ 59.000942][ C0] ? intel_pmu_handle_irq+0x284/0x620
[ 59.000954][ C0] </NMI>
[ 59.000957][ C0] WARNING: stack recursion on stack type 6
[ 59.000960][ C0] Modules linked in:
[ 59.120070][ C0] ---[ end trace 07eb1e3908914794 ]---
[ 59.120075][ C0] RIP: 0010:perf_swevent_get_recursion_context+0x0/0x70
[ 59.120087][ C0] Code: 48 03 43 28 48 8b 0c 24 bb 01 00 00 00 4c 29 f0 48 39 c8 48 0f 47 c1 49 89 45 08 e9 48 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 <55> 53 e8 89 18 f2 ff 48 c7 c2 20 4d 03 00 65 48 03 15 5a 34 d2 7e
[ 59.120092][ C0] RSP: 0018:fffffe000000b000 EFLAGS: 00010046
[ 59.120098][ C0] RAX: 0000000080120005 RBX: fffffe000000b050 RCX: 0000000000000000
[ 59.120102][ C0] RDX: ffff888106f5a180 RSI: ffffffff812696d1 RDI: 000000000000001c
[ 59.120106][ C0] RBP: 000000000000001c R08: 0000000000000001 R09: 0000000000000000
[ 59.120110][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 59.120114][ C0] R13: fffffe000000b044 R14: 0000000000000001 R15: 0000000000000001
[ 59.120118][ C0] FS: 00007f21fc62c740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
[ 59.120125][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 59.120129][ C0] CR2: fffffe000000aff8 CR3: 0000000106e2e001 CR4: 00000000003606f0
[ 59.120133][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 59.120137][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 59.120141][ C0] Kernel panic - not syncing: Fatal exception in interrupt
[ 59.120540][ C0] Kernel Offset: disabled
And below is the way of reproduce:
// autogenerated by syzkaller (https://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
static void sleep_ms(uint64_t ms)
{
usleep(ms * 1000);
}
static uint64_t current_time_ms(void)
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts))
exit(1);
return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}
#define BITMASK(bf_off,bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type,htobe,addr,val,bf_off,bf_len) *(type*)(addr) = htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))
static bool write_file(const char* file, const char* what, ...)
{
char buf[1024];
va_list args;
va_start(args, what);
vsnprintf(buf, sizeof(buf), what, args);
va_end(args);
buf[sizeof(buf) - 1] = 0;
int len = strlen(buf);
int fd = open(file, O_WRONLY | O_CLOEXEC);
if (fd == -1)
return false;
if (write(fd, buf, len) != len) {
int err = errno;
close(fd);
errno = err;
return false;
}
close(fd);
return true;
}
static void kill_and_wait(int pid, int* status)
{
kill(-pid, SIGKILL);
kill(pid, SIGKILL);
for (int i = 0; i < 100; i++) {
if (waitpid(-1, status, WNOHANG | __WALL) == pid)
return;
usleep(1000);
}
DIR* dir = opendir("/sys/fs/fuse/connections");
if (dir) {
for (;;) {
struct dirent* ent = readdir(dir);
if (!ent)
break;
if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
continue;
char abort[300];
snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name);
int fd = open(abort, O_WRONLY);
if (fd == -1) {
continue;
}
if (write(fd, abort, 1) < 0) {
}
close(fd);
}
closedir(dir);
} else {
}
while (waitpid(-1, status, __WALL) != pid) {
}
}
static void setup_test()
{
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
setpgrp();
write_file("/proc/self/oom_score_adj", "1000");
}
static void execute_one(void);
#define WAIT_FLAGS __WALL
static void loop(void)
{
int iter = 0;
for (;; iter++) {
int pid = fork();
if (pid < 0)
exit(1);
if (pid == 0) {
setup_test();
execute_one();
exit(0);
}
int status = 0;
uint64_t start = current_time_ms();
for (;;) {
if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
break;
sleep_ms(1);
if (current_time_ms() - start < 5000) {
continue;
}
kill_and_wait(pid, &status);
break;
}
}
}
void execute_one(void)
{
*(uint32_t*)0x20000380 = 2;
*(uint32_t*)0x20000384 = 0x70;
*(uint8_t*)0x20000388 = 1;
*(uint8_t*)0x20000389 = 0;
*(uint8_t*)0x2000038a = 0;
*(uint8_t*)0x2000038b = 0;
*(uint32_t*)0x2000038c = 0;
*(uint64_t*)0x20000390 = 0;
*(uint64_t*)0x20000398 = 0;
*(uint64_t*)0x200003a0 = 0;
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 0, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 1, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 2, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 3, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 4, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 5, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 6, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 7, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 8, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 9, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 10, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 11, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 12, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 13, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 14, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 15, 2);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 17, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 18, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 19, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 20, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 21, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 22, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 23, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 24, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 25, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 26, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 27, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 28, 1);
STORE_BY_BITMASK(uint64_t, , 0x200003a8, 0, 29, 35);
*(uint32_t*)0x200003b0 = 0;
*(uint32_t*)0x200003b4 = 0;
*(uint64_t*)0x200003b8 = 0;
*(uint64_t*)0x200003c0 = 0;
*(uint64_t*)0x200003c8 = 0;
*(uint64_t*)0x200003d0 = 0;
*(uint32_t*)0x200003d8 = 0;
*(uint32_t*)0x200003dc = 0;
*(uint64_t*)0x200003e0 = 0;
*(uint32_t*)0x200003e8 = 0;
*(uint16_t*)0x200003ec = 0;
*(uint16_t*)0x200003ee = 0;
syscall(__NR_perf_event_open, 0x20000380ul, -1, 0ul, -1, 0ul);
*(uint32_t*)0x20000080 = 0;
*(uint32_t*)0x20000084 = 0x70;
*(uint8_t*)0x20000088 = 0;
*(uint8_t*)0x20000089 = 0;
*(uint8_t*)0x2000008a = 0;
*(uint8_t*)0x2000008b = 0;
*(uint32_t*)0x2000008c = 0;
*(uint64_t*)0x20000090 = 0x9c;
*(uint64_t*)0x20000098 = 0;
*(uint64_t*)0x200000a0 = 0;
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 0, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 1, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 2, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 3, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 4, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 5, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 6, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 7, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 8, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 9, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 10, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 11, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 12, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 13, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 14, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 15, 2);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 17, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 18, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 19, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 20, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 21, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 22, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 23, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 24, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 25, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 26, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 27, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 28, 1);
STORE_BY_BITMASK(uint64_t, , 0x200000a8, 0, 29, 35);
*(uint32_t*)0x200000b0 = 0;
*(uint32_t*)0x200000b4 = 0;
*(uint64_t*)0x200000b8 = 0;
*(uint64_t*)0x200000c0 = 0;
*(uint64_t*)0x200000c8 = 0;
*(uint64_t*)0x200000d0 = 0;
*(uint32_t*)0x200000d8 = 0;
*(uint32_t*)0x200000dc = 0;
*(uint64_t*)0x200000e0 = 0;
*(uint32_t*)0x200000e8 = 0;
*(uint16_t*)0x200000ec = 0;
*(uint16_t*)0x200000ee = 0;
syscall(__NR_perf_event_open, 0x20000080ul, -1, 0ul, -1, 0ul);
*(uint32_t*)0x20000140 = 2;
*(uint32_t*)0x20000144 = 0x70;
*(uint8_t*)0x20000148 = 0x47;
*(uint8_t*)0x20000149 = 1;
*(uint8_t*)0x2000014a = 0;
*(uint8_t*)0x2000014b = 0;
*(uint32_t*)0x2000014c = 0;
*(uint64_t*)0x20000150 = 9;
*(uint64_t*)0x20000158 = 0x61220;
*(uint64_t*)0x20000160 = 0;
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 0, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 1, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 2, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 3, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 4, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 5, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 6, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 7, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 8, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 9, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 10, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 11, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 12, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 13, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 14, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 15, 2);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 17, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 18, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 19, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 20, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 21, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 22, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 23, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 24, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 25, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 26, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 27, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 28, 1);
STORE_BY_BITMASK(uint64_t, , 0x20000168, 0, 29, 35);
*(uint32_t*)0x20000170 = 0;
*(uint32_t*)0x20000174 = 0;
*(uint64_t*)0x20000178 = 0;
*(uint64_t*)0x20000180 = 0;
*(uint64_t*)0x20000188 = 0;
*(uint64_t*)0x20000190 = 1;
*(uint32_t*)0x20000198 = 0;
*(uint32_t*)0x2000019c = 0;
*(uint64_t*)0x200001a0 = 2;
*(uint32_t*)0x200001a8 = 0;
*(uint16_t*)0x200001ac = 0;
*(uint16_t*)0x200001ae = 0;
syscall(__NR_perf_event_open, 0x20000140ul, 0, -1ul, -1, 0ul);
}
int main(void)
{
syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
loop();
return 0;
}
Regards,
Michael Wang
On 2021/9/13 下午10:49, Dave Hansen wrote:
> On 9/12/21 8:30 PM, 王贇 wrote:
>> According to the trace we know the story is like this, the NMI
>> triggered perf IRQ throttling and call perf_log_throttle(),
>> which triggered the swevent overflow, and the overflow process
>> do perf_callchain_user() which triggered a user PF, and the PF
>> process triggered perf ftrace which finally lead into a suspected
>> stack overflow.
>>
>> This patch disable ftrace on fault.c, which help to avoid the panic.
> ...
>> +# Disable ftrace to avoid stack overflow.
>> +CFLAGS_REMOVE_fault.o = $(CC_FLAGS_FTRACE)
>
> Was this observed on a mainline kernel?
>
> How reproducible is this?
>
> I suspect we're going into do_user_addr_fault(), then falling in here:
>
>> if (unlikely(faulthandler_disabled() || !mm)) {
>> bad_area_nosemaphore(regs, error_code, address);
>> return;
>> }
>
> Then something double faults in perf_swevent_get_recursion_context().
> But, you snipped all of the register dump out so I can't quite see
> what's going on and what might have caused *that* fault. But, in my
> kernel perf_swevent_get_recursion_context+0x0/0x70 is:
>
> mov $0x27d00,%rdx
>
> which is rather unlikely to fault.
>
> Either way, we don't want to keep ftrace out of fault.c. This patch is
> just a hack, and doesn't really try to fix the underlying problem. This
> situation *should* be handled today. There's code there to handle it.
>
> Something else really funky is going on.
>