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Message-ID: <517f3f820807020404u7dbe6dc9n7754209200827a97@mail.gmail.com>
Date: Wed, 2 Jul 2008 13:04:52 +0200
From: "Michael Kerrisk" <mtk.manpages@...il.com>
To: "eranian@...glemail.com" <eranian@...glemail.com>
Cc: linux-kernel@...r.kernel.org
Subject: Re: [patch 17/19] perfmon2 minimal v3: system calls
On 6/30/08, eranian@...glemail.com <eranian@...glemail.com> wrote:
> This patch adds the top level perfmon2 system calls.
>
> Signed-off-by: Stephane Eranian <eranian@...il.com>
Stephane,
Is their some documentation for these new system calls?
Cheers,
Michael
===================================================================
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ linux-next/perfmon/perfmon_syscalls.c 2008-06-30 13:48:28.000000000 +0200
> @@ -0,0 +1,719 @@
> +/*
> + * perfmon_syscalls.c: perfmon2 system call interface
> + *
> + * This file implements the perfmon2 interface which
> + * provides access to the hardware performance counters
> + * of the host processor.
> + *
> + * The initial version of perfmon.c was written by
> + * Ganesh Venkitachalam, IBM Corp.
> + *
> + * Then it was modified for perfmon-1.x by Stephane Eranian and
> + * David Mosberger, Hewlett Packard Co.
> + *
> + * Version Perfmon-2.x is a complete rewrite of perfmon-1.x
> + * by Stephane Eranian, Hewlett Packard Co.
> + *
> + * Copyright (c) 1999-2006 Hewlett-Packard Development Company, L.P.
> + * Contributed by Stephane Eranian <eranian@....hp.com>
> + * David Mosberger-Tang <davidm@....hp.com>
> + *
> + * More information about perfmon available at:
> + * http://perfmon2.sf.net
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> + * 02111-1307 USA
> + */
> +#include <linux/kernel.h>
> +#include <linux/fs.h>
> +#include <linux/ptrace.h>
> +#include <linux/perfmon_kern.h>
> +#include <linux/uaccess.h>
> +#include "perfmon_priv.h"
> +
> +/*
> + * Context locking rules:
> + * ---------------------
> + * - any thread with access to the file descriptor of a context can
> + * potentially issue perfmon calls
> + *
> + * - calls must be serialized to guarantee correctness
> + *
> + * - as soon as a context is attached to a thread or CPU, it may be
> + * actively monitoring. On some architectures, such as IA-64, this
> + * is true even though the pfm_start() call has not been made. This
> + * comes from the fact that on some architectures, it is possible to
> + * start/stop monitoring from userland.
> + *
> + * - If monitoring is active, then there can PMU interrupts. Because
> + * context accesses must be serialized, the perfmon system calls
> + * must mask interrupts as soon as the context is attached.
> + *
> + * - perfmon system calls that operate with the context unloaded cannot
> + * assume it is actually unloaded when they are called. They first need
> + * to check and for that they need interrupts masked. Then, if the
> + * context is actually unloaded, they can unmask interrupts.
> + *
> + * - interrupt masking holds true for other internal perfmon functions as
> + * well. Except for PMU interrupt handler because those interrupts
> + * cannot be nested.
> + *
> + * - we mask ALL interrupts instead of just the PMU interrupt because we
> + * also need to protect against timer interrupts which could trigger
> + * a set switch.
> + */
> +
> +/*
> + * upper limit for count in calls that take vector arguments. This is used
> + * to prevent for multiplication overflow when we compute actual storage size
> + */
> +#define PFM_MAX_ARG_COUNT(m) (INT_MAX/sizeof(*(m)))
> +
> +struct pfm_syscall_cookie {
> + struct file *filp;
> + int fput_needed;
> +};
> +
> +/*
> + * cannot attach if :
> + * - kernel task
> + * - task not owned by caller (checked by ptrace_may_attach())
> + * - task is dead or zombie
> + * - cannot use blocking notification when self-monitoring
> + */
> +static int pfm_task_incompatible(struct pfm_context *ctx,
> + struct task_struct *task)
> +{
> + /*
> + * cannot attach to a kernel thread
> + */
> + if (!task->mm) {
> + PFM_DBG("cannot attach to kernel thread [%d]", task->pid);
> + return -EPERM;
> + }
> +
> + /*
> + * cannot attach to a zombie task
> + */
> + if (task->exit_state == EXIT_ZOMBIE || task->exit_state == EXIT_DEAD) {
> + PFM_DBG("cannot attach to zombie/dead task [%d]", task->pid);
> + return -EBUSY;
> + }
> + return 0;
> +}
> +
> +/**
> + * pfm_get_task -- check permission and acquire task to monitor
> + * @ctx: perfmon context
> + * @pid: identification of the task to check
> + * @task: upon return, a pointer to the task to monitor
> + *
> + * This function is used in per-thread mode only AND when not
> + * self-monitoring. It finds the task to monitor and checks
> + * that the caller has permissions to attach. It also checks
> + * that the task is stopped via ptrace so that we can safely
> + * modify its state.
> + *
> + * task refcount is incremented when succesful.
> + */
> +static int pfm_get_task(struct pfm_context *ctx, pid_t pid,
> + struct task_struct **task)
> +{
> + struct task_struct *p;
> + int ret = 0, ret1 = 0;
> +
> + /*
> + * When attaching to another thread we must ensure
> + * that the thread is actually stopped. Just like with
> + * perfmon system calls, we enforce that the thread
> + * be ptraced and STOPPED by using ptrace_check_attach().
> + *
> + * As a consequence, only the ptracing parent can actually
> + * attach a context to a thread. Obviously, this constraint
> + * does not exist for self-monitoring threads.
> + *
> + * We use ptrace_may_attach() to check for permission.
> + */
> + read_lock(&tasklist_lock);
> +
> + p = find_task_by_pid(pid);
> + if (p)
> + get_task_struct(p);
> +
> + read_unlock(&tasklist_lock);
> +
> + if (!p) {
> + PFM_DBG("task not found %d", pid);
> + return -ESRCH;
> + }
> +
> + ret = -EPERM;
> +
> + /*
> + * returns 0 if cannot attach
> + */
> + ret1 = ptrace_may_access(p, PTRACE_MODE_ATTACH);
> + if (ret1)
> + ret = ptrace_check_attach(p, 0);
> +
> + PFM_DBG("may_attach=%d check_attach=%d", ret1, ret);
> +
> + if (ret || !ret1)
> + goto error;
> +
> + ret = pfm_task_incompatible(ctx, p);
> + if (ret)
> + goto error;
> +
> + *task = p;
> +
> + return 0;
> +error:
> + if (!(ret1 || ret))
> + ret = -EPERM;
> +
> + put_task_struct(p);
> +
> + return ret;
> +}
> +
> +/*
> + * context must be locked when calling this function
> + */
> +int __pfm_check_task_state(struct pfm_context *ctx, int check_mask,
> + unsigned long *flags)
> +{
> + struct task_struct *task;
> + unsigned long local_flags, new_flags;
> + int state, ret;
> +
> +recheck:
> + /*
> + * task is NULL for system-wide context
> + */
> + task = ctx->task;
> + state = ctx->state;
> + local_flags = *flags;
> +
> + PFM_DBG("state=%d check_mask=0x%x task=[%d]",
> + state, check_mask, task ? task->pid:-1);
> + /*
> + * if the context is detached, then we do not touch
> + * hardware, therefore there is not restriction on when we can
> + * access it.
> + */
> + if (state == PFM_CTX_UNLOADED)
> + return 0;
> + /*
> + * no command can operate on a zombie context.
> + * A context becomes zombie when the file that identifies
> + * it is closed while the context is still attached to the
> + * thread it monitors.
> + */
> + if (state == PFM_CTX_ZOMBIE)
> + return -EINVAL;
> +
> + /*
> + * at this point, state is PFM_CTX_LOADED
> + */
> +
> + /*
> + * some commands require the context to be unloaded to operate
> + */
> + if (check_mask & PFM_CMD_UNLOADED) {
> + PFM_DBG("state=%d, cmd needs context unloaded", state);
> + return -EBUSY;
> + }
> +
> + /*
> + * self-monitoring always ok.
> + */
> + if (task == current)
> + return 0;
> +
> + /*
> + * at this point, monitoring another thread
> + */
> +
> + /*
> + * When we operate on another thread, we must wait for it to be
> + * stopped and completely off any CPU as we need to access the
> + * PMU state (or machine state).
> + *
> + * A thread can be put in the STOPPED state in various ways
> + * including PTRACE_ATTACH, or when it receives a SIGSTOP signal.
> + * We enforce that the thread must be ptraced, so it is stopped
> + * AND it CANNOT wake up while we operate on it because this
> + * would require an action from the ptracing parent which is the
> + * thread that is calling this function.
> + *
> + * The dependency on ptrace, imposes that only the ptracing
> + * parent can issue command on a thread. This is unfortunate
> + * but we do not know of a better way of doing this.
> + */
> + if (check_mask & PFM_CMD_STOPPED) {
> +
> + spin_unlock_irqrestore(&ctx->lock, local_flags);
> +
> + /*
> + * check that the thread is ptraced AND STOPPED
> + */
> + ret = ptrace_check_attach(task, 0);
> +
> + spin_lock_irqsave(&ctx->lock, new_flags);
> +
> + /*
> + * flags may be different than when we released the lock
> + */
> + *flags = new_flags;
> +
> + if (ret)
> + return ret;
> + /*
> + * we must recheck to verify if state has changed
> + */
> + if (unlikely(ctx->state != state)) {
> + PFM_DBG("old_state=%d new_state=%d",
> + state,
> + ctx->state);
> + goto recheck;
> + }
> + }
> + return 0;
> +}
> +
> +int pfm_check_task_state(struct pfm_context *ctx, int check_mask,
> + unsigned long *flags)
> +{
> + int ret;
> + ret = __pfm_check_task_state(ctx, check_mask, flags);
> + PFM_DBG("ret=%d",ret);
> + return ret;
> +}
> +
> +/*
> + * pfm_get_args - Function used to copy the syscall argument into kernel memory
> + * @ureq: user argument
> + * @sz: user argument size
> + * @lsz: size of stack buffer
> + * @laddr: stack buffer address
> + * @req: point to start of kernel copy of the argument
> + * @ptr_free: address of kernel copy to free
> + *
> + * There are two options:
> + * - use a stack buffer described by laddr (addresses) and lsz (size)
> + * - allocate memory
> + *
> + * return:
> + * < 0 : in case of error (ptr_free may not be updated)
> + * 0 : success
> + * - req: points to base of kernel copy of arguments
> + * - ptr_free: address of buffer to free by caller on exit.
> + * NULL if using the stack buffer
> + *
> + * when ptr_free is not NULL upon return, the caller must kfree()
> + */
> +int pfm_get_args(void __user *ureq, size_t sz, size_t lsz, void *laddr,
> + void **req, void **ptr_free)
> +{
> + void *addr;
> +
> + /*
> + * check syadmin argument limit
> + */
> + if (unlikely(sz > pfm_controls.arg_mem_max)) {
> + PFM_DBG("argument too big %zu max=%zu",
> + sz,
> + pfm_controls.arg_mem_max);
> + return -E2BIG;
> + }
> +
> + /*
> + * check if vector fits on stack buffer
> + */
> + if (sz > lsz) {
> + addr = kmalloc(sz, GFP_KERNEL);
> + if (unlikely(addr == NULL))
> + return -ENOMEM;
> + *ptr_free = addr;
> + } else {
> + addr = laddr;
> + *req = laddr;
> + *ptr_free = NULL;
> + }
> +
> + /*
> + * bring the data in
> + */
> + if (unlikely(copy_from_user(addr, ureq, sz))) {
> + if (addr != laddr)
> + kfree(addr);
> + return -EFAULT;
> + }
> +
> + /*
> + * base address of kernel buffer
> + */
> + *req = addr;
> +
> + return 0;
> +}
> +
> +/**
> + * pfm_acquire_ctx_from_fd -- get ctx from file descriptor
> + * @fd: file descriptor
> + * @ctx: pointer to pointer of context updated on return
> + * @cookie: opaque structure to use for release
> + *
> + * This helper function extracts the ctx from the file descriptor.
> + * It also increments the refcount of the file structure. Thus
> + * it updates the cookie so the refcount can be decreased when
> + * leaving the perfmon syscall via pfm_release_ctx_from_fd
> + */
> +static int pfm_acquire_ctx_from_fd(int fd, struct pfm_context **ctx,
> + struct pfm_syscall_cookie *cookie)
> +{
> + struct file *filp;
> + int fput_needed;
> +
> + filp = fget_light(fd, &fput_needed);
> + if (unlikely(filp == NULL)) {
> + PFM_DBG("invalid fd %d", fd);
> + return -EBADF;
> + }
> +
> + *ctx = filp->private_data;
> +
> + if (unlikely(!*ctx || filp->f_op != &pfm_file_ops)) {
> + PFM_DBG("fd %d not related to perfmon", fd);
> + return -EBADF;
> + }
> + cookie->filp = filp;
> + cookie->fput_needed = fput_needed;
> +
> + return 0;
> +}
> +
> +/**
> + * pfm_release_ctx_from_fd -- decrease refcount of file associated with context
> + * @cookie: the cookie structure initialized by pfm_acquire_ctx_from_fd
> + */
> +static inline void pfm_release_ctx_from_fd(struct pfm_syscall_cookie *cookie)
> +{
> + fput_light(cookie->filp, cookie->fput_needed);
> +}
> +
> +/*
> + * unlike the other perfmon system calls, this one returns a file descriptor
> + * or a value < 0 in case of error, very much like open() or socket()
> + */
> +asmlinkage long sys_pfm_create_context(struct pfarg_ctx __user *ureq,
> + char __user *fmt_name,
> + void __user *fmt_uarg, size_t fmt_size)
> +{
> + struct pfarg_ctx req;
> +
> + PFM_DBG("req=%p fmt=%p fmt_arg=%p size=%zu",
> + ureq, fmt_name, fmt_uarg, fmt_size);
> +
> + if (perfmon_disabled)
> + return -ENOSYS;
> +
> + if (copy_from_user(&req, ureq, sizeof(req)))
> + return -EFAULT;
> +
> + if (fmt_name || fmt_uarg || fmt_size)
> + return -EINVAL;
> +
> + return __pfm_create_context(req.ctx_flags);
> +}
> +
> +asmlinkage long sys_pfm_write_pmcs(int fd, struct pfarg_pmc __user *ureq,
> + int count)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + struct pfarg_pmc pmcs[PFM_PMC_STK_ARG];
> + struct pfarg_pmc *req;
> + void *fptr;
> + unsigned long flags;
> + size_t sz;
> + int ret;
> +
> + PFM_DBG("fd=%d req=%p count=%d", fd, ureq, count);
> +
> + if (count < 0 || count >= PFM_MAX_ARG_COUNT(ureq)) {
> + PFM_DBG("invalid arg count %d", count);
> + return -EINVAL;
> + }
> +
> + sz = count*sizeof(*ureq);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + ret = pfm_get_args(ureq, sz, sizeof(pmcs), pmcs, (void **)&req, &fptr);
> + if (ret)
> + goto error;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED, &flags);
> + if (!ret)
> + ret = __pfm_write_pmcs(ctx, req, count);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + /*
> + * This function may be on the critical path.
> + * We want to avoid the branch if unecessary.
> + */
> + if (fptr)
> + kfree(fptr);
> +error:
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_write_pmds(int fd, struct pfarg_pmd __user *ureq,
> + int count)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + struct pfarg_pmd pmds[PFM_PMD_STK_ARG];
> + struct pfarg_pmd *req;
> + void *fptr;
> + unsigned long flags;
> + size_t sz;
> + int ret;
> +
> + PFM_DBG("fd=%d req=%p count=%d", fd, ureq, count);
> +
> + if (count < 0 || count >= PFM_MAX_ARG_COUNT(ureq)) {
> + PFM_DBG("invalid arg count %d", count);
> + return -EINVAL;
> + }
> +
> + sz = count*sizeof(*ureq);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + ret = pfm_get_args(ureq, sz, sizeof(pmds), pmds, (void **)&req, &fptr);
> + if (ret)
> + goto error;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED, &flags);
> + if (!ret)
> + ret = __pfm_write_pmds(ctx, req, count);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + if (fptr)
> + kfree(fptr);
> +error:
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_read_pmds(int fd, struct pfarg_pmd __user *ureq,
> + int count)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + struct pfarg_pmd pmds[PFM_PMD_STK_ARG];
> + struct pfarg_pmd *req;
> + void *fptr;
> + unsigned long flags;
> + size_t sz;
> + int ret;
> +
> + PFM_DBG("fd=%d req=%p count=%d", fd, ureq, count);
> +
> + if (count < 0 || count >= PFM_MAX_ARG_COUNT(ureq))
> + return -EINVAL;
> +
> + sz = count*sizeof(*ureq);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + ret = pfm_get_args(ureq, sz, sizeof(pmds), pmds, (void **)&req, &fptr);
> + if (ret)
> + goto error;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED, &flags);
> + if (!ret)
> + ret = __pfm_read_pmds(ctx, req, count);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + if (copy_to_user(ureq, req, sz))
> + ret = -EFAULT;
> +
> + if (fptr)
> + kfree(fptr);
> +error:
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_stop(int fd)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + unsigned long flags;
> + int ret;
> +
> + PFM_DBG("fd=%d", fd);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED, &flags);
> + if (!ret)
> + ret = __pfm_stop(ctx);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_start(int fd)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + unsigned long flags;
> + int ret;
> +
> + PFM_DBG("fd=%d", fd);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED, &flags);
> + if (!ret)
> + ret = __pfm_start(ctx);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_load_context(int fd, struct pfarg_load __user *ureq)
> +{
> + struct pfarg_load req;
> + struct pfm_context *ctx;
> + struct task_struct *task;
> + struct pfm_syscall_cookie cookie;
> + unsigned long flags;
> + int ret;
> +
> + PFM_DBG("fd=%d ureq=%p", fd, ureq);
> +
> + if (copy_from_user(&req, ureq, sizeof(req)))
> + return -EFAULT;
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + task = current;
> +
> + /*
> + * in per-thread mode (not self-monitoring), get a reference
> + * on task to monitor. This must be done with interrupts enabled
> + * Upon succesful return, refcount on task is increased.
> + *
> + * fget_light() is protecting the context.
> + */
> + if (req.load_pid != current->pid) {
> + ret = pfm_get_task(ctx, req.load_pid, &task);
> + if (ret)
> + goto error;
> + }
> +
> + /*
> + * irqsave is required to avoid race in case context is already
> + * loaded or with switch timeout in the case of self-monitoring
> + */
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_UNLOADED, &flags);
> + if (!ret)
> + ret = __pfm_load_context(ctx, task);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + /*
> + * in per-thread mode (not self-monitoring), we need
> + * to decrease refcount on task to monitor:
> + * - load successful: we have a reference to the task in ctx->task
> + * - load failed : undo the effect of pfm_get_task()
> + */
> + if (task != current)
> + put_task_struct(task);
> +error:
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> +
> +asmlinkage long sys_pfm_unload_context(int fd)
> +{
> + struct pfm_context *ctx;
> + struct pfm_syscall_cookie cookie;
> + unsigned long flags;
> + int ret;
> +
> + PFM_DBG("fd=%d", fd);
> +
> + ret = pfm_acquire_ctx_from_fd(fd, &ctx, &cookie);
> + if (ret)
> + return ret;
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> +
> + ret = pfm_check_task_state(ctx, PFM_CMD_STOPPED|PFM_CMD_UNLOAD,
> + &flags);
> + if (!ret)
> + ret = __pfm_unload_context(ctx);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +
> + /*
> + * if unload was successful, then release the session
> + * must be called with interrupts enabled, thus we need
> + * to defer until are out of __pfm_unload_context()
> + */
> + if (!ret)
> + pfm_session_release();
> +
> + pfm_release_ctx_from_fd(&cookie);
> + return ret;
> +}
> Index: linux-next/include/linux/perfmon.h
> ===================================================================
> --- linux-next.orig/include/linux/perfmon.h 2008-06-26 20:06:58.000000000 +0200
> +++ linux-next/include/linux/perfmon.h 2008-06-30 13:48:29.000000000 +0200
> @@ -46,6 +46,16 @@
> #define PFM_PMC_BV PFM_BVSIZE(PFM_MAX_PMCS)
>
> /*
> + * argument to pfm_create_context() system call
> + * structure shared with user level
> + */
> +struct pfarg_ctx {
> + __u32 ctx_flags; /* context flags */
> + __u32 ctx_reserved1; /* for future use */
> + __u64 ctx_reserved2[7]; /* for future use */
> +};
> +
> +/*
> * argument to pfm_write_pmcs() system call.
> * structure shared with user level
> */
> @@ -70,6 +80,17 @@
> };
>
> /*
> + * argument to pfm_load_context() system call.
> + * structure shared with user level
> + */
> +struct pfarg_load {
> + __u32 load_pid; /* thread or CPU to attach to */
> + __u16 load_reserved0; /* for future use */
> + __u16 load_reserved1; /* for future use */
> + __u64 load_reserved2[3]; /* for future use */
> +};
> +
> +/*
> * default value for the user and group security parameters in
> * /proc/sys/kernel/perfmon/sys_group
> * /proc/sys/kernel/perfmon/task_group
> Index: linux-next/kernel/sys_ni.c
> ===================================================================
> --- linux-next.orig/kernel/sys_ni.c 2008-06-26 17:46:28.000000000 +0200
> +++ linux-next/kernel/sys_ni.c 2008-06-26 20:07:41.000000000 +0200
> @@ -161,3 +161,13 @@
> cond_syscall(compat_sys_timerfd_settime);
> cond_syscall(compat_sys_timerfd_gettime);
> cond_syscall(sys_eventfd);
> +
> +/* perfmon */
> +cond_syscall(sys_pfm_create_context);
> +cond_syscall(sys_pfm_write_pmcs);
> +cond_syscall(sys_pfm_write_pmds);
> +cond_syscall(sys_pfm_read_pmds);
> +cond_syscall(sys_pfm_start);
> +cond_syscall(sys_pfm_stop);
> +cond_syscall(sys_pfm_load_context);
> +cond_syscall(sys_pfm_unload_context);
> Index: linux-next/perfmon/Makefile
> ===================================================================
> --- linux-next.orig/perfmon/Makefile 2008-06-26 20:07:01.000000000 +0200
> +++ linux-next/perfmon/Makefile 2008-06-30 13:48:28.000000000 +0200
> @@ -7,4 +7,5 @@
> perfmon_init.o perfmon_ctxsw.o \
> perfmon_intr.o perfmon_pmu.o \
> perfmon_sysfs.o perfmon_rw.o \
> - perfmon_activate.o perfmon_attach.o
> + perfmon_activate.o perfmon_attach.o \
> + perfmon_syscalls.o
>
> --
>
>
> --
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>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html
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