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authorSrinivasarao P <spathi@codeaurora.org>2018-01-09 16:05:02 +0530
committerSrinivasarao P <spathi@codeaurora.org>2018-01-18 12:49:58 +0530
commit2d309c994df3624f59114edea6c03dd7cf3f334d (patch)
treedc435837f02d89571f8139262e796e46fa91f228 /kernel/kcov.c
parentdd4f1e35fa5f5a452d34e1fcc681472f2011f93d (diff)
parent79f138ac8c951ea1a06df9c869d16cc983613ac9 (diff)
Merge android-4.4.107 (79f138a) into msm-4.4
* refs/heads/tmp-79f138a Linux 4.4.107 ath9k: fix tx99 potential info leak IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop RDMA/cma: Avoid triggering undefined behavior macvlan: Only deliver one copy of the frame to the macvlan interface udf: Avoid overflow when session starts at large offset scsi: bfa: integer overflow in debugfs scsi: sd: change allow_restart to bool in sysfs interface scsi: sd: change manage_start_stop to bool in sysfs interface vt6655: Fix a possible sleep-in-atomic bug in vt6655_suspend scsi: scsi_devinfo: Add REPORTLUN2 to EMC SYMMETRIX blacklist entry raid5: Set R5_Expanded on parity devices as well as data. pinctrl: adi2: Fix Kconfig build problem usb: musb: da8xx: fix babble condition handling tty fix oops when rmmod 8250 powerpc/perf/hv-24x7: Fix incorrect comparison in memord scsi: hpsa: destroy sas transport properties before scsi_host scsi: hpsa: cleanup sas_phy structures in sysfs when unloading PCI: Detach driver before procfs & sysfs teardown on device remove xfs: fix incorrect extent state in xfs_bmap_add_extent_unwritten_real xfs: fix log block underflow during recovery cycle verification l2tp: cleanup l2tp_tunnel_delete calls bcache: fix wrong cache_misses statistics bcache: explicitly destroy mutex while exiting GFS2: Take inode off order_write list when setting jdata flag thermal/drivers/step_wise: Fix temperature regulation misbehavior ppp: Destroy the mutex when cleanup clk: tegra: Fix cclk_lp divisor register clk: imx6: refine hdmi_isfr's parent to make HDMI work on i.MX6 SoCs w/o VPU clk: mediatek: add the option for determining PLL source clock mm: Handle 0 flags in _calc_vm_trans() macro crypto: tcrypt - fix buffer lengths in test_aead_speed() arm-ccn: perf: Prevent module unload while PMU is in use target/file: Do not return error for UNMAP if length is zero target:fix condition return in core_pr_dump_initiator_port() iscsi-target: fix memory leak in lio_target_tiqn_addtpg() target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd() powerpc/ipic: Fix status get and status clear powerpc/opal: Fix EBUSY bug in acquiring tokens netfilter: ipvs: Fix inappropriate output of procfs powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo PCI/PME: Handle invalid data when reading Root Status dmaengine: ti-dma-crossbar: Correct am335x/am43xx mux value type rtc: pcf8563: fix output clock rate video: fbdev: au1200fb: Return an error code if a memory allocation fails video: fbdev: au1200fb: Release some resources if a memory allocation fails video: udlfb: Fix read EDID timeout fbdev: controlfb: Add missing modes to fix out of bounds access sfc: don't warn on successful change of MAC target: fix race during implicit transition work flushes target: fix ALUA transition timeout handling target: Use system workqueue for ALUA transitions btrfs: add missing memset while reading compressed inline extents NFSv4.1 respect server's max size in CREATE_SESSION efi/esrt: Cleanup bad memory map log messages perf symbols: Fix symbols__fixup_end heuristic for corner cases net/mlx4_core: Avoid delays during VF driver device shutdown afs: Fix afs_kill_pages() afs: Fix page leak in afs_write_begin() afs: Populate and use client modification time afs: Fix the maths in afs_fs_store_data() afs: Prevent callback expiry timer overflow afs: Migrate vlocation fields to 64-bit afs: Flush outstanding writes when an fd is closed afs: Adjust mode bits processing afs: Populate group ID from vnode status afs: Fix missing put_page() drm/radeon: reinstate oland workaround for sclk mmc: mediatek: Fixed bug where clock frequency could be set wrong sched/deadline: Use deadline instead of period when calculating overflow sched/deadline: Throttle a constrained deadline task activated after the deadline sched/deadline: Make sure the replenishment timer fires in the next period drm/radeon/si: add dpm quirk for Oland fjes: Fix wrong netdevice feature flags scsi: hpsa: limit outstanding rescans scsi: hpsa: update check for logical volume status openrisc: fix issue handling 8 byte get_user calls intel_th: pci: Add Gemini Lake support mlxsw: reg: Fix SPVMLR max record count mlxsw: reg: Fix SPVM max record count net: Resend IGMP memberships upon peer notification. dmaengine: Fix array index out of bounds warning in __get_unmap_pool() net: wimax/i2400m: fix NULL-deref at probe writeback: fix memory leak in wb_queue_work() netfilter: bridge: honor frag_max_size when refragmenting drm/omap: fix dmabuf mmap for dma_alloc'ed buffers Input: i8042 - add TUXEDO BU1406 (N24_25BU) to the nomux list NFSD: fix nfsd_reset_versions for NFSv4. NFSD: fix nfsd_minorversion(.., NFSD_AVAIL) net: bcmgenet: Power up the internal PHY before probing the MII net: bcmgenet: power down internal phy if open or resume fails net: bcmgenet: reserved phy revisions must be checked first net: bcmgenet: correct MIB access of UniMAC RUNT counters net: bcmgenet: correct the RBUF_OVFL_CNT and RBUF_ERR_CNT MIB values net: initialize msg.msg_flags in recvfrom userfaultfd: selftest: vm: allow to build in vm/ directory userfaultfd: shmem: __do_fault requires VM_FAULT_NOPAGE md-cluster: free md_cluster_info if node leave cluster usb: phy: isp1301: Add OF device ID table mac80211: Fix addition of mesh configuration element KEYS: add missing permission check for request_key() destination ext4: fix crash when a directory's i_size is too small ext4: fix fdatasync(2) after fallocate(2) operation dmaengine: dmatest: move callback wait queue to thread context sched/rt: Do not pull from current CPU if only one CPU to pull xhci: Don't add a virt_dev to the devs array before it's fully allocated Bluetooth: btusb: driver to enable the usb-wakeup feature ceph: drop negative child dentries before try pruning inode's alias usbip: fix stub_send_ret_submit() vulnerability to null transfer_buffer USB: core: prevent malicious bNumInterfaces overflow USB: uas and storage: Add US_FL_BROKEN_FUA for another JMicron JMS567 ID tracing: Allocate mask_str buffer dynamically autofs: fix careless error in recent commit crypto: salsa20 - fix blkcipher_walk API usage crypto: hmac - require that the underlying hash algorithm is unkeyed UPSTREAM: arm64: setup: introduce kaslr_offset() UPSTREAM: kcov: fix comparison callback signature UPSTREAM: kcov: support comparison operands collection UPSTREAM: kcov: remove pointless current != NULL check UPSTREAM: kcov: support compat processes UPSTREAM: kcov: simplify interrupt check UPSTREAM: kcov: make kcov work properly with KASLR enabled UPSTREAM: kcov: add more missing includes UPSTREAM: kcov: add missing #include <linux/sched.h> UPSTREAM: kcov: properly check if we are in an interrupt UPSTREAM: kcov: don't profile branches in kcov UPSTREAM: kcov: don't trace the code coverage code BACKPORT: kernel: add kcov code coverage Conflicts: Makefile mm/kasan/Makefile scripts/Makefile.lib Change-Id: Ic19953706ea2e700621b0ba94d1c90bbffa4f471 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
Diffstat (limited to 'kernel/kcov.c')
-rw-r--r--kernel/kcov.c431
1 files changed, 431 insertions, 0 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c
new file mode 100644
index 000000000000..5813e9375a93
--- /dev/null
+++ b/kernel/kcov.c
@@ -0,0 +1,431 @@
+#define pr_fmt(fmt) "kcov: " fmt
+
+#define DISABLE_BRANCH_PROFILING
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/preempt.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/kcov.h>
+#include <asm/setup.h>
+
+/* Number of 64-bit words written per one comparison: */
+#define KCOV_WORDS_PER_CMP 4
+
+/*
+ * kcov descriptor (one per opened debugfs file).
+ * State transitions of the descriptor:
+ * - initial state after open()
+ * - then there must be a single ioctl(KCOV_INIT_TRACE) call
+ * - then, mmap() call (several calls are allowed but not useful)
+ * - then, ioctl(KCOV_ENABLE, arg), where arg is
+ * KCOV_TRACE_PC - to trace only the PCs
+ * or
+ * KCOV_TRACE_CMP - to trace only the comparison operands
+ * - then, ioctl(KCOV_DISABLE) to disable the task.
+ * Enabling/disabling ioctls can be repeated (only one task a time allowed).
+ */
+struct kcov {
+ /*
+ * Reference counter. We keep one for:
+ * - opened file descriptor
+ * - task with enabled coverage (we can't unwire it from another task)
+ */
+ atomic_t refcount;
+ /* The lock protects mode, size, area and t. */
+ spinlock_t lock;
+ enum kcov_mode mode;
+ /* Size of arena (in long's for KCOV_MODE_TRACE). */
+ unsigned size;
+ /* Coverage buffer shared with user space. */
+ void *area;
+ /* Task for which we collect coverage, or NULL. */
+ struct task_struct *t;
+};
+
+static bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t)
+{
+ enum kcov_mode mode;
+
+ /*
+ * We are interested in code coverage as a function of a syscall inputs,
+ * so we ignore code executed in interrupts.
+ */
+ if (!in_task())
+ return false;
+ mode = READ_ONCE(t->kcov_mode);
+ /*
+ * There is some code that runs in interrupts but for which
+ * in_interrupt() returns false (e.g. preempt_schedule_irq()).
+ * READ_ONCE()/barrier() effectively provides load-acquire wrt
+ * interrupts, there are paired barrier()/WRITE_ONCE() in
+ * kcov_ioctl_locked().
+ */
+ barrier();
+ return mode == needed_mode;
+}
+
+static unsigned long canonicalize_ip(unsigned long ip)
+{
+#ifdef CONFIG_RANDOMIZE_BASE
+ ip -= kaslr_offset();
+#endif
+ return ip;
+}
+
+/*
+ * Entry point from instrumented code.
+ * This is called once per basic-block/edge.
+ */
+void notrace __sanitizer_cov_trace_pc(void)
+{
+ struct task_struct *t;
+ unsigned long *area;
+ unsigned long ip = canonicalize_ip(_RET_IP_);
+ unsigned long pos;
+
+ t = current;
+ if (!check_kcov_mode(KCOV_MODE_TRACE_PC, t))
+ return;
+
+ area = t->kcov_area;
+ /* The first 64-bit word is the number of subsequent PCs. */
+ pos = READ_ONCE(area[0]) + 1;
+ if (likely(pos < t->kcov_size)) {
+ area[pos] = ip;
+ WRITE_ONCE(area[0], pos);
+ }
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_pc);
+
+#ifdef CONFIG_KCOV_ENABLE_COMPARISONS
+static void write_comp_data(u64 type, u64 arg1, u64 arg2, u64 ip)
+{
+ struct task_struct *t;
+ u64 *area;
+ u64 count, start_index, end_pos, max_pos;
+
+ t = current;
+ if (!check_kcov_mode(KCOV_MODE_TRACE_CMP, t))
+ return;
+
+ ip = canonicalize_ip(ip);
+
+ /*
+ * We write all comparison arguments and types as u64.
+ * The buffer was allocated for t->kcov_size unsigned longs.
+ */
+ area = (u64 *)t->kcov_area;
+ max_pos = t->kcov_size * sizeof(unsigned long);
+
+ count = READ_ONCE(area[0]);
+
+ /* Every record is KCOV_WORDS_PER_CMP 64-bit words. */
+ start_index = 1 + count * KCOV_WORDS_PER_CMP;
+ end_pos = (start_index + KCOV_WORDS_PER_CMP) * sizeof(u64);
+ if (likely(end_pos <= max_pos)) {
+ area[start_index] = type;
+ area[start_index + 1] = arg1;
+ area[start_index + 2] = arg2;
+ area[start_index + 3] = ip;
+ WRITE_ONCE(area[0], count + 1);
+ }
+}
+
+void notrace __sanitizer_cov_trace_cmp1(u8 arg1, u8 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(0), arg1, arg2, _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_cmp1);
+
+void notrace __sanitizer_cov_trace_cmp2(u16 arg1, u16 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(1), arg1, arg2, _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_cmp2);
+
+void notrace __sanitizer_cov_trace_cmp4(u32 arg1, u32 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(2), arg1, arg2, _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_cmp4);
+
+void notrace __sanitizer_cov_trace_cmp8(u64 arg1, u64 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(3), arg1, arg2, _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_cmp8);
+
+void notrace __sanitizer_cov_trace_const_cmp1(u8 arg1, u8 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(0) | KCOV_CMP_CONST, arg1, arg2,
+ _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp1);
+
+void notrace __sanitizer_cov_trace_const_cmp2(u16 arg1, u16 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(1) | KCOV_CMP_CONST, arg1, arg2,
+ _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp2);
+
+void notrace __sanitizer_cov_trace_const_cmp4(u32 arg1, u32 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(2) | KCOV_CMP_CONST, arg1, arg2,
+ _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp4);
+
+void notrace __sanitizer_cov_trace_const_cmp8(u64 arg1, u64 arg2)
+{
+ write_comp_data(KCOV_CMP_SIZE(3) | KCOV_CMP_CONST, arg1, arg2,
+ _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp8);
+
+void notrace __sanitizer_cov_trace_switch(u64 val, u64 *cases)
+{
+ u64 i;
+ u64 count = cases[0];
+ u64 size = cases[1];
+ u64 type = KCOV_CMP_CONST;
+
+ switch (size) {
+ case 8:
+ type |= KCOV_CMP_SIZE(0);
+ break;
+ case 16:
+ type |= KCOV_CMP_SIZE(1);
+ break;
+ case 32:
+ type |= KCOV_CMP_SIZE(2);
+ break;
+ case 64:
+ type |= KCOV_CMP_SIZE(3);
+ break;
+ default:
+ return;
+ }
+ for (i = 0; i < count; i++)
+ write_comp_data(type, cases[i + 2], val, _RET_IP_);
+}
+EXPORT_SYMBOL(__sanitizer_cov_trace_switch);
+#endif /* ifdef CONFIG_KCOV_ENABLE_COMPARISONS */
+
+static void kcov_get(struct kcov *kcov)
+{
+ atomic_inc(&kcov->refcount);
+}
+
+static void kcov_put(struct kcov *kcov)
+{
+ if (atomic_dec_and_test(&kcov->refcount)) {
+ vfree(kcov->area);
+ kfree(kcov);
+ }
+}
+
+void kcov_task_init(struct task_struct *t)
+{
+ t->kcov_mode = KCOV_MODE_DISABLED;
+ t->kcov_size = 0;
+ t->kcov_area = NULL;
+ t->kcov = NULL;
+}
+
+void kcov_task_exit(struct task_struct *t)
+{
+ struct kcov *kcov;
+
+ kcov = t->kcov;
+ if (kcov == NULL)
+ return;
+ spin_lock(&kcov->lock);
+ if (WARN_ON(kcov->t != t)) {
+ spin_unlock(&kcov->lock);
+ return;
+ }
+ /* Just to not leave dangling references behind. */
+ kcov_task_init(t);
+ kcov->t = NULL;
+ kcov->mode = KCOV_MODE_INIT;
+ spin_unlock(&kcov->lock);
+ kcov_put(kcov);
+}
+
+static int kcov_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+ int res = 0;
+ void *area;
+ struct kcov *kcov = vma->vm_file->private_data;
+ unsigned long size, off;
+ struct page *page;
+
+ area = vmalloc_user(vma->vm_end - vma->vm_start);
+ if (!area)
+ return -ENOMEM;
+
+ spin_lock(&kcov->lock);
+ size = kcov->size * sizeof(unsigned long);
+ if (kcov->mode != KCOV_MODE_INIT || vma->vm_pgoff != 0 ||
+ vma->vm_end - vma->vm_start != size) {
+ res = -EINVAL;
+ goto exit;
+ }
+ if (!kcov->area) {
+ kcov->area = area;
+ vma->vm_flags |= VM_DONTEXPAND;
+ spin_unlock(&kcov->lock);
+ for (off = 0; off < size; off += PAGE_SIZE) {
+ page = vmalloc_to_page(kcov->area + off);
+ if (vm_insert_page(vma, vma->vm_start + off, page))
+ WARN_ONCE(1, "vm_insert_page() failed");
+ }
+ return 0;
+ }
+exit:
+ spin_unlock(&kcov->lock);
+ vfree(area);
+ return res;
+}
+
+static int kcov_open(struct inode *inode, struct file *filep)
+{
+ struct kcov *kcov;
+
+ kcov = kzalloc(sizeof(*kcov), GFP_KERNEL);
+ if (!kcov)
+ return -ENOMEM;
+ kcov->mode = KCOV_MODE_DISABLED;
+ atomic_set(&kcov->refcount, 1);
+ spin_lock_init(&kcov->lock);
+ filep->private_data = kcov;
+ return nonseekable_open(inode, filep);
+}
+
+static int kcov_close(struct inode *inode, struct file *filep)
+{
+ kcov_put(filep->private_data);
+ return 0;
+}
+
+static int kcov_ioctl_locked(struct kcov *kcov, unsigned int cmd,
+ unsigned long arg)
+{
+ struct task_struct *t;
+ unsigned long size, unused;
+
+ switch (cmd) {
+ case KCOV_INIT_TRACE:
+ /*
+ * Enable kcov in trace mode and setup buffer size.
+ * Must happen before anything else.
+ */
+ if (kcov->mode != KCOV_MODE_DISABLED)
+ return -EBUSY;
+ /*
+ * Size must be at least 2 to hold current position and one PC.
+ * Later we allocate size * sizeof(unsigned long) memory,
+ * that must not overflow.
+ */
+ size = arg;
+ if (size < 2 || size > INT_MAX / sizeof(unsigned long))
+ return -EINVAL;
+ kcov->size = size;
+ kcov->mode = KCOV_MODE_INIT;
+ return 0;
+ case KCOV_ENABLE:
+ /*
+ * Enable coverage for the current task.
+ * At this point user must have been enabled trace mode,
+ * and mmapped the file. Coverage collection is disabled only
+ * at task exit or voluntary by KCOV_DISABLE. After that it can
+ * be enabled for another task.
+ */
+ if (kcov->mode != KCOV_MODE_INIT || !kcov->area)
+ return -EINVAL;
+ if (kcov->t != NULL)
+ return -EBUSY;
+ if (arg == KCOV_TRACE_PC)
+ kcov->mode = KCOV_MODE_TRACE_PC;
+ else if (arg == KCOV_TRACE_CMP)
+#ifdef CONFIG_KCOV_ENABLE_COMPARISONS
+ kcov->mode = KCOV_MODE_TRACE_CMP;
+#else
+ return -ENOTSUPP;
+#endif
+ else
+ return -EINVAL;
+ t = current;
+ /* Cache in task struct for performance. */
+ t->kcov_size = kcov->size;
+ t->kcov_area = kcov->area;
+ /* See comment in check_kcov_mode(). */
+ barrier();
+ WRITE_ONCE(t->kcov_mode, kcov->mode);
+ t->kcov = kcov;
+ kcov->t = t;
+ /* This is put either in kcov_task_exit() or in KCOV_DISABLE. */
+ kcov_get(kcov);
+ return 0;
+ case KCOV_DISABLE:
+ /* Disable coverage for the current task. */
+ unused = arg;
+ if (unused != 0 || current->kcov != kcov)
+ return -EINVAL;
+ t = current;
+ if (WARN_ON(kcov->t != t))
+ return -EINVAL;
+ kcov_task_init(t);
+ kcov->t = NULL;
+ kcov->mode = KCOV_MODE_INIT;
+ kcov_put(kcov);
+ return 0;
+ default:
+ return -ENOTTY;
+ }
+}
+
+static long kcov_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+ struct kcov *kcov;
+ int res;
+
+ kcov = filep->private_data;
+ spin_lock(&kcov->lock);
+ res = kcov_ioctl_locked(kcov, cmd, arg);
+ spin_unlock(&kcov->lock);
+ return res;
+}
+
+static const struct file_operations kcov_fops = {
+ .open = kcov_open,
+ .unlocked_ioctl = kcov_ioctl,
+ .compat_ioctl = kcov_ioctl,
+ .mmap = kcov_mmap,
+ .release = kcov_close,
+};
+
+static int __init kcov_init(void)
+{
+ if (!debugfs_create_file("kcov", 0600, NULL, NULL, &kcov_fops)) {
+ pr_err("failed to create kcov in debugfs\n");
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+device_initcall(kcov_init);