/* * Controller of read/write threads for virtio-trace * * Copyright (C) 2012 Hitachi, Ltd. * Created by Yoshihiro Yunomae * Masami Hiramatsu * * Licensed under GPL version 2 only. * */ #define _GNU_SOURCE #include #include #include #include #include #include #include "trace-agent.h" #define HOST_MSG_SIZE 256 #define EVENT_WAIT_MSEC 100 static volatile sig_atomic_t global_signal_val; bool global_sig_receive; /* default false */ bool global_run_operation; /* default false*/ /* Handle SIGTERM/SIGINT/SIGQUIT to exit */ static void signal_handler(int sig) { global_signal_val = sig; } int rw_ctl_init(const char *ctl_path) { int ctl_fd; ctl_fd = open(ctl_path, O_RDONLY); if (ctl_fd == -1) { pr_err("Cannot open ctl_fd\n"); goto error; } return ctl_fd; error: exit(EXIT_FAILURE); } static int wait_order(int ctl_fd) { struct pollfd poll_fd; int ret = 0; while (!global_sig_receive) { poll_fd.fd = ctl_fd; poll_fd.events = POLLIN; ret = poll(&poll_fd, 1, EVENT_WAIT_MSEC); if (global_signal_val) { global_sig_receive = true; pr_info("Receive interrupt %d\n", global_signal_val); /* Wakes rw-threads when they are sleeping */ if (!global_run_operation) pthread_cond_broadcast(&cond_wakeup); ret = -1; break; } if (ret < 0) { pr_err("Polling error\n"); goto error; } if (ret) break; }; return ret; error: exit(EXIT_FAILURE); } /* * contol read/write threads by handling global_run_operation */ void *rw_ctl_loop(int ctl_fd) { ssize_t rlen; char buf[HOST_MSG_SIZE]; int ret; /* Setup signal handlers */ signal(SIGTERM, signal_handler); signal(SIGINT, signal_handler); signal(SIGQUIT, signal_handler); while (!global_sig_receive) { ret = wait_order(ctl_fd); if (ret < 0) break; rlen = read(ctl_fd, buf, sizeof(buf)); if (rlen < 0) { pr_err("read data error in ctl thread\n"); goto error; } if (rlen == 2 && buf[0] == '1') { /* * If host writes '1' to a control path, * this controller wakes all read/write threads. */ global_run_operation = true; pthread_cond_broadcast(&cond_wakeup); pr_debug("Wake up all read/write threads\n"); } else if (rlen == 2 && buf[0] == '0') { /* * If host writes '0' to a control path, read/write * threads will wait for notification from Host. */ global_run_operation = false; pr_debug("Stop all read/write threads\n"); } else pr_info("Invalid host notification: %s\n", buf); } return NULL; error: exit(EXIT_FAILURE); } /select>
path: root/tools/testing/selftests/powerpc/stringloops/asm
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authorDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
commit54791b276b4000b307339f269d3bf7db877d536f (patch)
tree1c2616bd373ce5ea28aac2a53e32f5b5834901ce /tools/testing/selftests/powerpc/stringloops/asm
parent5d0e7705774dd412a465896d08d59a81a345c1e4 (diff)
parent047487241ff59374fded8c477f21453681f5995c (diff)
Merge branch 'sparc64-non-resumable-user-error-recovery'
Liam R. Howlett says: ==================== sparc64: Recover from userspace non-resumable PIO & MEM errors A non-resumable error from userspace is able to cause a kernel panic or trap loop due to the setup and handling of the queued traps once in the kernel. This patch series addresses both of these issues. The queues are fixed by simply zeroing the memory before use. PIO errors from userspace will result in a SIGBUS being sent to the user process. The MEM errors form userspace will result in a SIGKILL and also cause the offending pages to be claimed so they are no longer used in future tasks. SIGKILL is used to ensure that the process does not try to coredump and result in an attempt to read the memory again from within kernel space. Although there is a HV call to scrub the memory (mem_scrub), there is no easy way to guarantee that the real memory address(es) are not used by other tasks. Clearing the error with mem_scrub would zero the memory and cause the other processes to proceed with bad data. The handling of other non-resumable errors remain unchanged and will cause a panic. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools/testing/selftests/powerpc/stringloops/asm')