whiterose

linux unikernel
Log | Files | Refs | README | LICENSE | git clone https://git.ne02ptzero.me/git/whiterose

commit 9bb9d4fdce9e6b351b7b905f150745a0fccccc06
parent adb6b2b2b59f7872322f255206583b4c3ce661a3
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 31 Oct 2018 15:46:16 -0700

Merge branch 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - removal of old and dead code

 - a bug fix for our tty driver

 - other minor cleanups across the code base

* 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Make line/tty semantics use true write IRQ
  um: trap: fix spelling mistake, EACCESS -> EACCES
  um: Don't hardcode path as it is architecture dependent
  um: NULL check before kfree is not needed
  um: remove unused AIO code
  um: Give start_idle_thread() a return code
  um: Remove update_debugregs()
  um: Drop own definition of PTRACE_SYSEMU/_SINGLESTEP

Diffstat:
March/um/drivers/line.c | 4++--
March/um/drivers/port_user.c | 2+-
March/um/drivers/vector_kern.c | 15+++++----------
March/um/drivers/vector_user.c | 6++----
Darch/um/include/shared/aio.h | 28----------------------------
March/um/kernel/irq.c | 3+--
March/um/kernel/trap.c | 2+-
March/um/os-Linux/Makefile | 8++------
Darch/um/os-Linux/aio.c | 390-------------------------------------------------------------------------------
March/um/os-Linux/skas/process.c | 5+++++
March/x86/um/shared/sysdep/ptrace_32.h | 12------------
11 files changed, 19 insertions(+), 456 deletions(-)

diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c @@ -261,7 +261,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data) if (err == 0) { spin_unlock(&line->lock); return IRQ_NONE; - } else if (err < 0) { + } else if ((err < 0) && (err != -EAGAIN)) { line->head = line->buffer; line->tail = line->buffer; } @@ -284,7 +284,7 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data) if (err) return err; if (output) - err = um_request_irq(driver->write_irq, fd, IRQ_NONE, + err = um_request_irq(driver->write_irq, fd, IRQ_WRITE, line_write_interrupt, IRQF_SHARED, driver->write_irq_name, data); return err; diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c @@ -168,7 +168,7 @@ int port_connection(int fd, int *socket, int *pid_out) { int new, err; char *argv[] = { "/usr/sbin/in.telnetd", "-L", - "/usr/lib/uml/port-helper", NULL }; + OS_LIB_PATH "/uml/port-helper", NULL }; struct port_pre_exec_data data; new = accept(fd, NULL, 0); diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c @@ -1118,16 +1118,11 @@ static int vector_net_close(struct net_device *dev) os_close_file(vp->fds->tx_fd); vp->fds->tx_fd = -1; } - if (vp->bpf != NULL) - kfree(vp->bpf); - if (vp->fds->remote_addr != NULL) - kfree(vp->fds->remote_addr); - if (vp->transport_data != NULL) - kfree(vp->transport_data); - if (vp->header_rxbuffer != NULL) - kfree(vp->header_rxbuffer); - if (vp->header_txbuffer != NULL) - kfree(vp->header_txbuffer); + kfree(vp->bpf); + kfree(vp->fds->remote_addr); + kfree(vp->transport_data); + kfree(vp->header_rxbuffer); + kfree(vp->header_txbuffer); if (vp->rx_queue != NULL) destroy_queue(vp->rx_queue); if (vp->tx_queue != NULL) diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c @@ -267,8 +267,7 @@ cleanup: os_close_file(rxfd); if (txfd >= 0) os_close_file(txfd); - if (result != NULL) - kfree(result); + kfree(result); return NULL; } @@ -434,8 +433,7 @@ cleanup: if (fd >= 0) os_close_file(fd); if (result != NULL) { - if (result->remote_addr != NULL) - kfree(result->remote_addr); + kfree(result->remote_addr); kfree(result); } return NULL; diff --git a/arch/um/include/shared/aio.h b/arch/um/include/shared/aio.h @@ -1,28 +0,0 @@ -/* - * Copyright (C) 2004 Jeff Dike (jdike@karaya.com) - * Licensed under the GPL - */ - -#ifndef AIO_H__ -#define AIO_H__ - -enum aio_type { AIO_READ, AIO_WRITE, AIO_MMAP }; - -struct aio_thread_reply { - void *data; - int err; -}; - -struct aio_context { - int reply_fd; - struct aio_context *next; -}; - -#define INIT_AIO_CONTEXT { .reply_fd = -1, \ - .next = NULL } - -extern int submit_aio(enum aio_type type, int fd, char *buf, int len, - unsigned long long offset, int reply_fd, - struct aio_context *aio); - -#endif diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c @@ -244,8 +244,7 @@ static void garbage_collect_irq_entries(void) to_free = NULL; } walk = walk->next; - if (to_free != NULL) - kfree(to_free); + kfree(to_free); } } diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c @@ -19,7 +19,7 @@ #include <skas.h> /* - * Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by + * Note this is constrained to return 0, -EFAULT, -EACCES, -ENOMEM by * segv(). */ int handle_page_fault(unsigned long address, unsigned long ip, diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile @@ -6,18 +6,14 @@ # Don't instrument UML-specific code KCOV_INSTRUMENT := n -obj-y = aio.o execvp.o file.o helper.o irq.o main.o mem.o process.o \ +obj-y = execvp.o file.o helper.o irq.o main.o mem.o process.o \ registers.o sigio.o signal.o start_up.o time.o tty.o \ umid.o user_syms.o util.o drivers/ skas/ obj-$(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA) += elf_aux.o -USER_OBJS := $(user-objs-y) aio.o elf_aux.o execvp.o file.o helper.o irq.o \ +USER_OBJS := $(user-objs-y) elf_aux.o execvp.o file.o helper.o irq.o \ main.o mem.o process.o registers.o sigio.o signal.o start_up.o time.o \ tty.o umid.o util.o -HAVE_AIO_ABI := $(shell [ -r /usr/include/linux/aio_abi.h ] && \ - echo -DHAVE_AIO_ABI ) -CFLAGS_aio.o += $(HAVE_AIO_ABI) - include arch/um/scripts/Makefile.rules diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c @@ -1,390 +0,0 @@ -/* - * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) - * Licensed under the GPL - */ - -#include <unistd.h> -#include <sched.h> -#include <signal.h> -#include <errno.h> -#include <sys/time.h> -#include <asm/unistd.h> -#include <aio.h> -#include <init.h> -#include <kern_util.h> -#include <os.h> - -struct aio_thread_req { - enum aio_type type; - int io_fd; - unsigned long long offset; - char *buf; - int len; - struct aio_context *aio; -}; - -#if defined(HAVE_AIO_ABI) -#include <linux/aio_abi.h> - -/* - * If we have the headers, we are going to build with AIO enabled. - * If we don't have aio in libc, we define the necessary stubs here. - */ - -#if !defined(HAVE_AIO_LIBC) - -static long io_setup(int n, aio_context_t *ctxp) -{ - return syscall(__NR_io_setup, n, ctxp); -} - -static long io_submit(aio_context_t ctx, long nr, struct iocb **iocbpp) -{ - return syscall(__NR_io_submit, ctx, nr, iocbpp); -} - -static long io_getevents(aio_context_t ctx_id, long min_nr, long nr, - struct io_event *events, struct timespec *timeout) -{ - return syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout); -} - -#endif - -/* - * The AIO_MMAP cases force the mmapped page into memory here - * rather than in whatever place first touches the data. I used - * to do this by touching the page, but that's delicate because - * gcc is prone to optimizing that away. So, what's done here - * is we read from the descriptor from which the page was - * mapped. The caller is required to pass an offset which is - * inside the page that was mapped. Thus, when the read - * returns, we know that the page is in the page cache, and - * that it now backs the mmapped area. - */ - -static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf, - int len, unsigned long long offset, struct aio_context *aio) -{ - struct iocb *iocbp = & ((struct iocb) { - .aio_data = (unsigned long) aio, - .aio_fildes = fd, - .aio_buf = (unsigned long) buf, - .aio_nbytes = len, - .aio_offset = offset - }); - char c; - - switch (type) { - case AIO_READ: - iocbp->aio_lio_opcode = IOCB_CMD_PREAD; - break; - case AIO_WRITE: - iocbp->aio_lio_opcode = IOCB_CMD_PWRITE; - break; - case AIO_MMAP: - iocbp->aio_lio_opcode = IOCB_CMD_PREAD; - iocbp->aio_buf = (unsigned long) &c; - iocbp->aio_nbytes = sizeof(c); - break; - default: - printk(UM_KERN_ERR "Bogus op in do_aio - %d\n", type); - return -EINVAL; - } - - return (io_submit(ctx, 1, &iocbp) > 0) ? 0 : -errno; -} - -/* Initialized in an initcall and unchanged thereafter */ -static aio_context_t ctx = 0; - -static int aio_thread(void *arg) -{ - struct aio_thread_reply reply; - struct io_event event; - int err, n, reply_fd; - - os_fix_helper_signals(); - while (1) { - n = io_getevents(ctx, 1, 1, &event, NULL); - if (n < 0) { - if (errno == EINTR) - continue; - printk(UM_KERN_ERR "aio_thread - io_getevents failed, " - "errno = %d\n", errno); - } - else { - reply = ((struct aio_thread_reply) - { .data = (void *) (long) event.data, - .err = event.res }); - reply_fd = ((struct aio_context *) reply.data)->reply_fd; - err = write(reply_fd, &reply, sizeof(reply)); - if (err != sizeof(reply)) - printk(UM_KERN_ERR "aio_thread - write failed, " - "fd = %d, err = %d\n", reply_fd, errno); - } - } - return 0; -} - -#endif - -static int do_not_aio(struct aio_thread_req *req) -{ - char c; - unsigned long long actual; - int n; - - actual = lseek64(req->io_fd, req->offset, SEEK_SET); - if (actual != req->offset) - return -errno; - - switch (req->type) { - case AIO_READ: - n = read(req->io_fd, req->buf, req->len); - break; - case AIO_WRITE: - n = write(req->io_fd, req->buf, req->len); - break; - case AIO_MMAP: - n = read(req->io_fd, &c, sizeof(c)); - break; - default: - printk(UM_KERN_ERR "do_not_aio - bad request type : %d\n", - req->type); - return -EINVAL; - } - - if (n < 0) - return -errno; - return 0; -} - -/* These are initialized in initcalls and not changed */ -static int aio_req_fd_r = -1; -static int aio_req_fd_w = -1; -static int aio_pid = -1; -static unsigned long aio_stack; - -static int not_aio_thread(void *arg) -{ - struct aio_thread_req req; - struct aio_thread_reply reply; - int err; - - os_fix_helper_signals(); - while (1) { - err = read(aio_req_fd_r, &req, sizeof(req)); - if (err != sizeof(req)) { - if (err < 0) - printk(UM_KERN_ERR "not_aio_thread - " - "read failed, fd = %d, err = %d\n", - aio_req_fd_r, - errno); - else { - printk(UM_KERN_ERR "not_aio_thread - short " - "read, fd = %d, length = %d\n", - aio_req_fd_r, err); - } - continue; - } - err = do_not_aio(&req); - reply = ((struct aio_thread_reply) { .data = req.aio, - .err = err }); - err = write(req.aio->reply_fd, &reply, sizeof(reply)); - if (err != sizeof(reply)) - printk(UM_KERN_ERR "not_aio_thread - write failed, " - "fd = %d, err = %d\n", req.aio->reply_fd, errno); - } - - return 0; -} - -static int init_aio_24(void) -{ - int fds[2], err; - - err = os_pipe(fds, 1, 1); - if (err) - goto out; - - aio_req_fd_w = fds[0]; - aio_req_fd_r = fds[1]; - - err = os_set_fd_block(aio_req_fd_w, 0); - if (err) - goto out_close_pipe; - - err = run_helper_thread(not_aio_thread, NULL, - CLONE_FILES | CLONE_VM, &aio_stack); - if (err < 0) - goto out_close_pipe; - - aio_pid = err; - goto out; - -out_close_pipe: - close(fds[0]); - close(fds[1]); - aio_req_fd_w = -1; - aio_req_fd_r = -1; -out: -#ifndef HAVE_AIO_ABI - printk(UM_KERN_INFO "/usr/include/linux/aio_abi.h not present during " - "build\n"); -#endif - printk(UM_KERN_INFO "2.6 host AIO support not used - falling back to " - "I/O thread\n"); - return 0; -} - -#ifdef HAVE_AIO_ABI -#define DEFAULT_24_AIO 0 -static int init_aio_26(void) -{ - int err; - - if (io_setup(256, &ctx)) { - err = -errno; - printk(UM_KERN_ERR "aio_thread failed to initialize context, " - "err = %d\n", errno); - return err; - } - - err = run_helper_thread(aio_thread, NULL, - CLONE_FILES | CLONE_VM, &aio_stack); - if (err < 0) - return err; - - aio_pid = err; - - printk(UM_KERN_INFO "Using 2.6 host AIO\n"); - return 0; -} - -static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len, - unsigned long long offset, struct aio_context *aio) -{ - struct aio_thread_reply reply; - int err; - - err = do_aio(ctx, type, io_fd, buf, len, offset, aio); - if (err) { - reply = ((struct aio_thread_reply) { .data = aio, - .err = err }); - err = write(aio->reply_fd, &reply, sizeof(reply)); - if (err != sizeof(reply)) { - err = -errno; - printk(UM_KERN_ERR "submit_aio_26 - write failed, " - "fd = %d, err = %d\n", aio->reply_fd, -err); - } - else err = 0; - } - - return err; -} - -#else -#define DEFAULT_24_AIO 1 -static int init_aio_26(void) -{ - return -ENOSYS; -} - -static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len, - unsigned long long offset, struct aio_context *aio) -{ - return -ENOSYS; -} -#endif - -/* Initialized in an initcall and unchanged thereafter */ -static int aio_24 = DEFAULT_24_AIO; - -static int __init set_aio_24(char *name, int *add) -{ - aio_24 = 1; - return 0; -} - -__uml_setup("aio=2.4", set_aio_24, -"aio=2.4\n" -" This is used to force UML to use 2.4-style AIO even when 2.6 AIO is\n" -" available. 2.4 AIO is a single thread that handles one request at a\n" -" time, synchronously. 2.6 AIO is a thread which uses the 2.6 AIO \n" -" interface to handle an arbitrary number of pending requests. 2.6 AIO \n" -" is not available in tt mode, on 2.4 hosts, or when UML is built with\n" -" /usr/include/linux/aio_abi.h not available. Many distributions don't\n" -" include aio_abi.h, so you will need to copy it from a kernel tree to\n" -" your /usr/include/linux in order to build an AIO-capable UML\n\n" -); - -static int init_aio(void) -{ - int err; - - if (!aio_24) { - err = init_aio_26(); - if (err && (errno == ENOSYS)) { - printk(UM_KERN_INFO "2.6 AIO not supported on the " - "host - reverting to 2.4 AIO\n"); - aio_24 = 1; - } - else return err; - } - - if (aio_24) - return init_aio_24(); - - return 0; -} - -/* - * The reason for the __initcall/__uml_exitcall asymmetry is that init_aio - * needs to be called when the kernel is running because it calls run_helper, - * which needs get_free_page. exit_aio is a __uml_exitcall because the generic - * kernel does not run __exitcalls on shutdown, and can't because many of them - * break when called outside of module unloading. - */ -__initcall(init_aio); - -static void exit_aio(void) -{ - if (aio_pid != -1) { - os_kill_process(aio_pid, 1); - free_stack(aio_stack, 0); - } -} - -__uml_exitcall(exit_aio); - -static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len, - unsigned long long offset, struct aio_context *aio) -{ - struct aio_thread_req req = { .type = type, - .io_fd = io_fd, - .offset = offset, - .buf = buf, - .len = len, - .aio = aio, - }; - int err; - - err = write(aio_req_fd_w, &req, sizeof(req)); - if (err == sizeof(req)) - err = 0; - else err = -errno; - - return err; -} - -int submit_aio(enum aio_type type, int io_fd, char *buf, int len, - unsigned long long offset, int reply_fd, - struct aio_context *aio) -{ - aio->reply_fd = reply_fd; - if (aio_24) - return submit_aio_24(type, io_fd, buf, len, offset, aio); - else - return submit_aio_26(type, io_fd, buf, len, offset, aio); -} diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c @@ -610,6 +610,11 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf) fatal_sigsegv(); } longjmp(*switch_buf, 1); + + /* unreachable */ + printk(UM_KERN_ERR "impossible long jump!"); + fatal_sigsegv(); + return 0; } void initial_thread_cb_skas(void (*proc)(void *), void *arg) diff --git a/arch/x86/um/shared/sysdep/ptrace_32.h b/arch/x86/um/shared/sysdep/ptrace_32.h @@ -8,22 +8,10 @@ #define MAX_FP_NR HOST_FPX_SIZE -static inline void update_debugregs(int seq) {} - -/* syscall emulation path in ptrace */ - -#ifndef PTRACE_SYSEMU -#define PTRACE_SYSEMU 31 -#endif - void set_using_sysemu(int value); int get_using_sysemu(void); extern int sysemu_supported; -#ifndef PTRACE_SYSEMU_SINGLESTEP -#define PTRACE_SYSEMU_SINGLESTEP 32 -#endif - #define UPT_SYSCALL_ARG1(r) UPT_BX(r) #define UPT_SYSCALL_ARG2(r) UPT_CX(r) #define UPT_SYSCALL_ARG3(r) UPT_DX(r)