Sysret_check system_call_after_swapgs
WebNov 19, 2024 · 0.78% presto-server [kernel.kallsyms] [k] system_call_after_swapgs 0.68% presto-server [kernel.kallsyms] [k] sysret_check 0.65% presto-server libzip.so [.] … WebMany operating systems use the GS segment register to reference application and kernel data that is specific to a thread or processor. In such cases, the operating system …
Sysret_check system_call_after_swapgs
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WebCore part is calling *sys_call_table(, %rax, 8). sys_call_table is an array of addresses of system calls, and rax has system call number and 8 is size of one entry of the table. The entry point of all system calls are the same but call *sys_call_table(, %rax, 8) instruction jumps to corresponding system call. Where is sys_call_table? Web* after an interrupt and after each system call. * * Normal syscalls and interrupts don't save a full stack frame, this is ... * after the swapgs, so that it can do the swapgs * for the guest and jump here on syscall. */ ... sysret_check: LOCKDEP_SYS_EXIT: DISABLE_INTERRUPTS(CLBR_NONE)
WebNMI watchdog: BUG: soft lockup - CPU#2 stuck for 40s! [kworker/2:2:66033] [] system_call_fastpath+0x25/0x2a [] ? … I also see that sysret_check is very high. I bet if you run general exploration, then extend frontend bound/frontend latency, you'll see high % of branch resteers. If so, this is likely a performance side effects of u-code patches against Spectre attacks, that clear BTB on system calls/returns to user mode.
Webnext prev parent reply other threads:[~2015-01-14 21:49 UTC newest] Thread overview: 130+ messages / expand[flat nested] mbox.gz Atom feed top 2015-01-14 21:48 [PATCH 01/11] x86: entry_64.S: always allocate complete "struct pt_regs" Denys Vlasenko 2015-01-14 21:48 ` [PATCH 02/11] x86: code shrink in paranoid_exit Denys Vlasenko 2015-02-11 20:36 ` … WebNov 7, 2024 · Linux kernel for Nexus 5 (hammerhead) Toggle navigation Toggle navigation pinning
WebApr 19, 2012 · Well, we can take SYSCALL as an example. After the processor saves the RFLAGS and the next instruction after the call, it has to get the ring0 privileged code to be executed, ie the target instruction and stack ptr.
WebLKML Archive on lore.kernel.org help / color / mirror / Atom feed * [RFC] sched, x86: Prevent resched interrupts if task in kernel mode and !CONFIG_PREEMPT @ 2015-01-23 15:53 Kirill Tkhai 2015-01-23 16:07 ` Peter Zijlstra 0 siblings, 1 reply; 7+ messages in thread From: Kirill Tkhai @ 2015-01-23 15:53 UTC (permalink / raw) To: linux-kernel; +Cc: Peter Zijlstra, … tithe houseWebAfter frequent oom, kernel crashed with below logs: [12581201.985136] [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name [12581201.985655] [ 9720] 0 9720 44153 389 47 140 985 su [12581201.985665] [ 9827] 0 9827 28811 343 15 67 985 bash [12581201.985673] [ 9856] 0 9856 12611759 909872 5224 1074492 985 java … tithe house horsforthWebSpectre is a class of side channel attacks that exploit branch prediction and speculative execution on modern CPUs to read memory, possibly bypassing access controls. Speculative execution side channel exploits do not modify memory but attempt to infer privileged data in the memory. This document covers Spectre variant 1 and Spectre … tithe holyWebAfter reviewing through the top log, you can see the system load average is high, with 32 cores on the machine. .D state code code means that the process is in uninterruptible sleep, and that may mean different things, but it is usually I/O. System load averages is the average number of processes that are either in a runnable or uninterruptable ... tithe how muchWebApr 14, 2024 · Just looking at the info perf top is currently giving me, the top two are system_call_after_swapgs, and sysret_check. Doing a bit of googling, it sounds like an … tithe holly black summaryWebSystem crashes with one of the following errors and stack traces BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: [] xfs_bmap_longest_free_extent+0x2f/0xb0 [xfs] ... Call Kernel panic following XFS filesystem corruption on RHEL - Red Hat Customer Portal tithe illustrationWebsystem_call: syscall instruction from 64-bit code. entry_INT80_compat: int 0x80 from 32-bit or 64-bit code; compat syscall either way. ... , which might have triggered right after a normal entry wrote CS to the stack but before we executed SWAPGS, then the only safe way to check for GS is the slower method: the RDMSR. Therefore, super-atomic ... tithe hvac