Commit graph

68 commits

Author SHA1 Message Date
Greg Kroah-Hartman
588b1f9c92 Merge 4.19.133 into android-4.19-stable
Changes in 4.19.133
	KVM: s390: reduce number of IO pins to 1
	spi: spi-fsl-dspi: Adding shutdown hook
	spi: spi-fsl-dspi: Fix lockup if device is removed during SPI transfer
	spi: spi-fsl-dspi: use IRQF_SHARED mode to request IRQ
	spi: spi-fsl-dspi: Fix external abort on interrupt in resume or exit paths
	regmap: fix alignment issue
	ARM: dts: omap4-droid4: Fix spi configuration and increase rate
	drm/tegra: hub: Do not enable orphaned window group
	gpu: host1x: Detach driver on unregister
	spi: spidev: fix a race between spidev_release and spidev_remove
	spi: spidev: fix a potential use-after-free in spidev_release()
	ixgbe: protect ring accesses with READ- and WRITE_ONCE
	i40e: protect ring accesses with READ- and WRITE_ONCE
	drm: panel-orientation-quirks: Add quirk for Asus T101HA panel
	drm: panel-orientation-quirks: Use generic orientation-data for Acer S1003
	s390/kasan: fix early pgm check handler execution
	cifs: update ctime and mtime during truncate
	ARM: imx6: add missing put_device() call in imx6q_suspend_init()
	scsi: mptscsih: Fix read sense data size
	usb: dwc3: pci: Fix reference count leak in dwc3_pci_resume_work
	block: release bip in a right way in error path
	nvme-rdma: assign completion vector correctly
	x86/entry: Increase entry_stack size to a full page
	net: qrtr: Fix an out of bounds read qrtr_endpoint_post()
	drm/mediatek: Check plane visibility in atomic_update
	net: cxgb4: fix return error value in t4_prep_fw
	smsc95xx: check return value of smsc95xx_reset
	smsc95xx: avoid memory leak in smsc95xx_bind
	net: hns3: fix use-after-free when doing self test
	ALSA: compress: fix partial_drain completion state
	arm64: kgdb: Fix single-step exception handling oops
	nbd: Fix memory leak in nbd_add_socket
	cxgb4: fix all-mask IP address comparison
	bnxt_en: fix NULL dereference in case SR-IOV configuration fails
	net: macb: mark device wake capable when "magic-packet" property present
	mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON()
	ALSA: opl3: fix infoleak in opl3
	ALSA: hda - let hs_mic be picked ahead of hp_mic
	ALSA: usb-audio: add quirk for MacroSilicon MS2109
	KVM: arm64: Fix definition of PAGE_HYP_DEVICE
	KVM: arm64: Stop clobbering x0 for HVC_SOFT_RESTART
	KVM: x86: bit 8 of non-leaf PDPEs is not reserved
	KVM: x86: Inject #GP if guest attempts to toggle CR4.LA57 in 64-bit mode
	KVM: x86: Mark CR4.TSD as being possibly owned by the guest
	kallsyms: Refactor kallsyms_show_value() to take cred
	kernel: module: Use struct_size() helper
	module: Refactor section attr into bin attribute
	module: Do not expose section addresses to non-CAP_SYSLOG
	kprobes: Do not expose probe addresses to non-CAP_SYSLOG
	bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()
	Revert "ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb"
	btrfs: fix fatal extent_buffer readahead vs releasepage race
	drm/radeon: fix double free
	dm: use noio when sending kobject event
	ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE
	ARC: elf: use right ELF_ARCH
	s390/mm: fix huge pte soft dirty copying
	Linux 4.19.133

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I0a0198d501017d2bc701b653d75dc9cedd1ebbd9
2020-07-17 07:54:52 +02:00
Kees Cook
ebce5c1fb5 kallsyms: Refactor kallsyms_show_value() to take cred
commit 160251842cd35a75edfb0a1d76afa3eb674ff40a upstream.

In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.

Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.

Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:26 +02:00
Will Deacon
8e37367a32 FROMGIT: kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()
kallsyms_lookup_name() and kallsyms_on_each_symbol() are exported to
modules despite having no in-tree users and being wide open to abuse by
out-of-tree modules that can use them as a method to invoke arbitrary
non-exported kernel functions.

Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol().

Bug: 149978696
Change-Id: I8f3c1b5222939c46901f4d149d4c7bb63916ff04
Link: http://lkml.kernel.org/r/20200221114404.14641-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Quentin Perret <qperret@google.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit ab3e66797c7fddbf80fbba31c5bf4574ad52f320
 https://github.com/hnaz/linux-mm.git master)
Signed-off-by: Quentin Perret <qperret@google.com>
2020-03-12 11:18:50 +00:00
Sami Tolvanen
4596eee0c8 ANDROID: kallsyms: strip hashes from function names with ThinLTO
With CONFIG_THINLTO and CFI both enabled, LLVM appends a hash to the
names of all static functions. This breaks userspace tools, so strip
out the hash from output.

Bug: 147422318
Change-Id: Ibea6be089d530e92dcd191481cb02549041203f6
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2020-01-31 16:50:06 +00:00
Greg Kroah-Hartman
de5730eaef This is the 4.19.75 stable release
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Merge 4.19.75 into android-4.19

Changes in 4.19.75
	netfilter: nf_flow_table: set default timeout after successful insertion
	HID: wacom: generic: read HID_DG_CONTACTMAX from any feature report
	RDMA/restrack: Release task struct which was hold by CM_ID object
	Input: elan_i2c - remove Lenovo Legion Y7000 PnpID
	powerpc/mm/radix: Use the right page size for vmemmap mapping
	USB: usbcore: Fix slab-out-of-bounds bug during device reset
	media: tm6000: double free if usb disconnect while streaming
	phy: renesas: rcar-gen3-usb2: Disable clearing VBUS in over-current
	ip6_gre: fix a dst leak in ip6erspan_tunnel_xmit
	udp: correct reuseport selection with connected sockets
	xen-netfront: do not assume sk_buff_head list is empty in error handling
	net_sched: let qdisc_put() accept NULL pointer
	KVM: coalesced_mmio: add bounds checking
	firmware: google: check if size is valid when decoding VPD data
	serial: sprd: correct the wrong sequence of arguments
	tty/serial: atmel: reschedule TX after RX was started
	mwifiex: Fix three heap overflow at parsing element in cfg80211_ap_settings
	nl80211: Fix possible Spectre-v1 for CQM RSSI thresholds
	ieee802154: hwsim: Fix error handle path in hwsim_init_module
	ieee802154: hwsim: unregister hw while hwsim_subscribe_all_others fails
	ARM: dts: am57xx: Disable voltage switching for SD card
	ARM: OMAP2+: Fix missing SYSC_HAS_RESET_STATUS for dra7 epwmss
	bus: ti-sysc: Fix using configured sysc mask value
	s390/bpf: fix lcgr instruction encoding
	ARM: OMAP2+: Fix omap4 errata warning on other SoCs
	ARM: dts: dra74x: Fix iodelay configuration for mmc3
	ARM: OMAP1: ams-delta-fiq: Fix missing irq_ack
	bus: ti-sysc: Simplify cleanup upon failures in sysc_probe()
	s390/bpf: use 32-bit index for tail calls
	selftests/bpf: fix "bind{4, 6} deny specific IP & port" on s390
	tools: bpftool: close prog FD before exit on showing a single program
	fpga: altera-ps-spi: Fix getting of optional confd gpio
	netfilter: ebtables: Fix argument order to ADD_COUNTER
	netfilter: nft_flow_offload: missing netlink attribute policy
	netfilter: xt_nfacct: Fix alignment mismatch in xt_nfacct_match_info
	NFSv4: Fix return values for nfs4_file_open()
	NFSv4: Fix return value in nfs_finish_open()
	NFS: Fix initialisation of I/O result struct in nfs_pgio_rpcsetup
	Kconfig: Fix the reference to the IDT77105 Phy driver in the description of ATM_NICSTAR_USE_IDT77105
	xdp: unpin xdp umem pages in error path
	qed: Add cleanup in qed_slowpath_start()
	ARM: 8874/1: mm: only adjust sections of valid mm structures
	batman-adv: Only read OGM2 tvlv_len after buffer len check
	bpf: allow narrow loads of some sk_reuseport_md fields with offset > 0
	r8152: Set memory to all 0xFFs on failed reg reads
	x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines
	netfilter: xt_physdev: Fix spurious error message in physdev_mt_check
	netfilter: nf_conntrack_ftp: Fix debug output
	NFSv2: Fix eof handling
	NFSv2: Fix write regression
	kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol
	cifs: set domainName when a domain-key is used in multiuser
	cifs: Use kzfree() to zero out the password
	usb: host: xhci-tegra: Set DMA mask correctly
	ARM: 8901/1: add a criteria for pfn_valid of arm
	ibmvnic: Do not process reset during or after device removal
	sky2: Disable MSI on yet another ASUS boards (P6Xxxx)
	i2c: designware: Synchronize IRQs when unregistering slave client
	perf/x86/intel: Restrict period on Nehalem
	perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops
	amd-xgbe: Fix error path in xgbe_mod_init()
	tools/power x86_energy_perf_policy: Fix "uninitialized variable" warnings at -O2
	tools/power x86_energy_perf_policy: Fix argument parsing
	tools/power turbostat: fix buffer overrun
	net: aquantia: fix out of memory condition on rx side
	net: seeq: Fix the function used to release some memory in an error handling path
	dmaengine: ti: dma-crossbar: Fix a memory leak bug
	dmaengine: ti: omap-dma: Add cleanup in omap_dma_probe()
	x86/uaccess: Don't leak the AC flags into __get_user() argument evaluation
	x86/hyper-v: Fix overflow bug in fill_gva_list()
	keys: Fix missing null pointer check in request_key_auth_describe()
	iommu/amd: Flush old domains in kdump kernel
	iommu/amd: Fix race in increase_address_space()
	PCI: kirin: Fix section mismatch warning
	ovl: fix regression caused by overlapping layers detection
	floppy: fix usercopy direction
	binfmt_elf: move brk out of mmap when doing direct loader exec
	arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field
	media: technisat-usb2: break out of loop at end of buffer
	Linux 4.19.75

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I1dd841f112ee81497cd085b102979f45ee5e6b9d
2019-09-21 07:55:26 +02:00
Marc Zyngier
9a74f799b9 kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol
[ Upstream commit 2a1a3fa0f29270583f0e6e3100d609e09697add1 ]

An arm64 kernel configured with

  CONFIG_KPROBES=y
  CONFIG_KALLSYMS=y
  # CONFIG_KALLSYMS_ALL is not set
  CONFIG_KALLSYMS_BASE_RELATIVE=y

reports the following kprobe failure:

  [    0.032677] kprobes: failed to populate blacklist: -22
  [    0.033376] Please take care of using kprobes.

It appears that kprobe fails to retrieve the symbol at address
0xffff000010081000, despite this symbol being in System.map:

  ffff000010081000 T __exception_text_start

This symbol is part of the first group of aliases in the
kallsyms_offsets array (symbol names generated using ugly hacks in
scripts/kallsyms.c):

  kallsyms_offsets:
          .long   0x1000 // do_undefinstr
          .long   0x1000 // efi_header_end
          .long   0x1000 // _stext
          .long   0x1000 // __exception_text_start
          .long   0x12b0 // do_cp15instr

Looking at the implementation of get_symbol_pos(), it returns the
lowest index for aliasing symbols. In this case, it return 0.

But kallsyms_lookup_size_offset() considers 0 as a failure, which
is obviously wrong (there is definitely a valid symbol living there).
In turn, the kprobe blacklisting stops abruptly, hence the original
error.

A CONFIG_KALLSYMS_ALL kernel wouldn't fail as there is always
some random symbols at the beginning of this array, which are never
looked up via kallsyms_lookup_size_offset.

Fix it by considering that get_symbol_pos() is always successful
(which is consistent with the other uses of this function).

Fixes: ffc5089196 ("[PATCH] Create kallsyms_lookup_size_offset()")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21 07:17:02 +02:00
Sami Tolvanen
05fb7fe5f3 ANDROID: kallsyms: strip the .cfi postfix from symbols with CONFIG_CFI_CLANG
With CFI enabled, LLVM appends .cfi to most function names, which
potentially breaks user space tools. While stripping the postfix is
not optimal either, this should at least create less confusion.

Bug: 67506682
Bug: 73328469
Bug: 133186739
Change-Id: I253f34a562629032ddd792b8498e171109ea7cbc
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2019-05-20 17:46:32 -07:00
Alexander Shishkin
d83212d5dd kallsyms, x86: Export addresses of PTI entry trampolines
Currently, the addresses of PTI entry trampolines are not exported to
user space. Kernel profiling tools need these addresses to identify the
kernel code, so add a symbol and address for each CPU's PTI entry
trampoline.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1528289651-4113-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-14 19:12:29 -03:00
Adrian Hunter
b966794220 kallsyms: Simplify update_iter_mod()
The logic in update_iter_mod() is overcomplicated and gets worse every
time another get_ksymbol_* function is added.

In preparation for adding another get_ksymbol_* function, simplify logic
in update_iter_mod().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: (ftrace changes only) Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1528289651-4113-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-14 19:10:23 -03:00
Linus Torvalds
ab486bc9a5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:

 - Add a console_msg_format command line option:

     The value "default" keeps the old "[time stamp] text\n" format. The
     value "syslog" allows to see the syslog-like "<log
     level>[timestamp] text" format.

     This feature was requested by people doing regression tests, for
     example, 0day robot. They want to have both filtered and full logs
     at hands.

 - Reduce the risk of softlockup:

     Pass the console owner in a busy loop.

     This is a new approach to the old problem. It was first proposed by
     Steven Rostedt on Kernel Summit 2017. It marks a context in which
     the console_lock owner calls console drivers and could not sleep.
     On the other side, printk() callers could detect this state and use
     a busy wait instead of a simple console_trylock(). Finally, the
     console_lock owner checks if there is a busy waiter at the end of
     the special context and eventually passes the console_lock to the
     waiter.

     The hand-off works surprisingly well and helps in many situations.
     Well, there is still a possibility of the softlockup, for example,
     when the flood of messages stops and the last owner still has too
     much to flush.

     There is increasing number of people having problems with
     printk-related softlockups. We might eventually need to get better
     solution. Anyway, this looks like a good start and promising
     direction.

 - Do not allow to schedule in console_unlock() called from printk():

     This reverts an older controversial commit. The reschedule helped
     to avoid softlockups. But it also slowed down the console output.
     This patch is obsoleted by the new console waiter logic described
     above. In fact, the reschedule made the hand-off less effective.

 - Deprecate "%pf" and "%pF" format specifier:

     It was needed on ia64, ppc64 and parisc64 to dereference function
     descriptors and show the real function address. It is done
     transparently by "%ps" and "pS" format specifier now.

     Sergey Senozhatsky found that all the function descriptors were in
     a special elf section and could be easily detected.

 - Remove printk_symbol() API:

     It has been obsoleted by "%pS" format specifier, and this change
     helped to remove few continuous lines and a less intuitive old API.

 - Remove redundant memsets:

     Sergey removed unnecessary memset when processing printk.devkmsg
     command line option.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
  printk: drop redundant devkmsg_log_str memsets
  printk: Never set console_may_schedule in console_trylock()
  printk: Hide console waiter logic into helpers
  printk: Add console owner and waiter logic to load balance console writes
  kallsyms: remove print_symbol() function
  checkpatch: add pF/pf deprecation warning
  symbol lookup: introduce dereference_symbol_descriptor()
  parisc64: Add .opd based function descriptor dereference
  powerpc64: Add .opd based function descriptor dereference
  ia64: Add .opd based function descriptor dereference
  sections: split dereference_function_descriptor()
  openrisc: Fix conflicting types for _exext and _stext
  lib: do not use print_symbol()
  irq debug: do not use print_symbol()
  sysfs: do not use print_symbol()
  drivers: do not use print_symbol()
  x86: do not use print_symbol()
  unicore32: do not use print_symbol()
  sh: do not use print_symbol()
  mn10300: do not use print_symbol()
  ...
2018-02-01 13:36:15 -08:00
Petr Mladek
51ccbb0ae8 Merge branch 'for-4.16-print-symbol' into for-4.16 2018-01-22 10:40:50 +01:00
Sergey Senozhatsky
d2279c9d7f kallsyms: remove print_symbol() function
No more print_symbol()/__print_symbol() users left, remove these
symbols.

It was a very old API that encouraged people use continuous lines.
It had been obsoleted by %pS format specifier in a normal printk()
call.

Link: http://lkml.kernel.org/r/20180105102538.GC471@jagdpanzerIV
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-am33-list@redhat.com
Cc: linux-sh@vger.kernel.org
Cc: linux-edac@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
[pmladek@suse.com: updated commit message]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-16 16:59:55 +01:00
Sergey Senozhatsky
04b8eb7a4c symbol lookup: introduce dereference_symbol_descriptor()
dereference_symbol_descriptor() invokes appropriate ARCH specific
function descriptor dereference callbacks:
- dereference_kernel_function_descriptor() if the pointer is a
  kernel symbol;

- dereference_module_function_descriptor() if the pointer is a
  module symbol.

This is the last step needed to make '%pS/%ps' smart enough to
handle function descriptor dereference on affected ARCHs and
to retire '%pF/%pf'.

To refresh it:
  Some architectures (ia64, ppc64, parisc64) use an indirect pointer
  for C function pointers - the function pointer points to a function
  descriptor and we need to dereference it to get the actual function
  pointer.

  Function descriptors live in .opd elf section and all affected
  ARCHs (ia64, ppc64, parisc64) handle it properly for kernel and
  modules. So we, technically, can decide if the dereference is
  needed by simply looking at the pointer: if it belongs to .opd
  section then we need to dereference it.

  The kernel and modules have their own .opd sections, obviously,
  that's why we need to split dereference_function_descriptor()
  and use separate kernel and module dereference arch callbacks.

Link: http://lkml.kernel.org/r/20171206043649.GB15885@jagdpanzerIV
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com> #ia64
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Tested-by: Helge Deller <deller@gmx.de> #parisc64
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-09 10:45:38 +01:00
Linus Torvalds
668533dc07 kallsyms: take advantage of the new '%px' format
The conditional kallsym hex printing used a special fixed-width '%lx'
output (KALLSYM_FMT) in preparation for the hashing of %p, but that
series ended up adding a %px specifier to help with the conversions.

Use it, and avoid the "print pointer as an unsigned long" code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29 10:30:13 -08:00
Linus Torvalds
2dcd9c71c1 Tracing updates for 4.15:
- Now allow module init functions to be traced
 
  - Clean up some unused or not used by config events (saves space)
 
  - Clean up of trace histogram code
 
  - Add support for preempt and interrupt enabled/disable events
 
  - Other various clean ups
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Merge tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from

 - allow module init functions to be traced

 - clean up some unused or not used by config events (saves space)

 - clean up of trace histogram code

 - add support for preempt and interrupt enabled/disable events

 - other various clean ups

* tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits)
  tracing, thermal: Hide cpu cooling trace events when not in use
  tracing, thermal: Hide devfreq trace events when not in use
  ftrace: Kill FTRACE_OPS_FL_PER_CPU
  perf/ftrace: Small cleanup
  perf/ftrace: Fix function trace events
  perf/ftrace: Revert ("perf/ftrace: Fix double traces of perf on ftrace:function")
  tracing, dma-buf: Remove unused trace event dma_fence_annotate_wait_on
  tracing, memcg, vmscan: Hide trace events when not in use
  tracing/xen: Hide events that are not used when X86_PAE is not defined
  tracing: mark trace_test_buffer as __maybe_unused
  printk: Remove superfluous memory barriers from printk_safe
  ftrace: Clear hashes of stale ips of init memory
  tracing: Add support for preempt and irq enable/disable events
  tracing: Prepare to add preempt and irq trace events
  ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions
  ftrace: Add freeing algorithm to free ftrace_mod_maps
  ftrace: Save module init functions kallsyms symbols for tracing
  ftrace: Allow module init functions to be traced
  ftrace: Add a ftrace_free_mem() function for modules to use
  tracing: Reimplement log2
  ...
2017-11-17 14:58:01 -08:00
Linus Torvalds
516fb7f2e7 /proc/module: use the same logic as /proc/kallsyms for address exposure
The (alleged) users of the module addresses are the same: kernel
profiling.

So just expose the same helper and format macros, and unify the logic.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-12 19:01:23 -08:00
Linus Torvalds
c0f3ea1589 stop using '%pK' for /proc/kallsyms pointer values
Not only is it annoying to have one single flag for all pointers, as if
that was a global choice and all kernel pointers are the same, but %pK
can't get the 'access' vs 'open' time check right anyway.

So make the /proc/kallsyms pointer value code use logic specific to that
particular file.  We do continue to honor kptr_restrict, but the default
(which is unrestricted) is changed to instead take expected users into
account, and restrict access by default.

Right now the only actual expected user is kernel profiling, which has a
separate sysctl flag for kernel profile access.  There may be others.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-08 12:51:04 -08:00
Steven Rostedt (VMware)
6171a0310a ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions
If a module is loaded while tracing is enabled, then there's a possibility
that the module init functions were traced. These functions have their name
and address stored by ftrace such that it can translate the function address
that is written into the buffer into a human readable function name.

As userspace tools may be doing the same, they need a way to map function
names to their address as well. This is done through reading /proc/kallsyms.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-10-05 23:10:42 -04:00
Steven Rostedt (VMware)
aba4b5c22c ftrace: Save module init functions kallsyms symbols for tracing
If function tracing is active when the module init functions are freed, then
store them to be referenced by kallsyms. As module init functions can now be
traced on module load, they were useless:

 ># echo ':mod:snd_seq' > set_ftrace_filter
 ># echo function > current_tracer
 ># modprobe snd_seq
 ># cat trace
 # tracer: function
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
         modprobe-2786  [000] ....  3189.037874: 0xffffffffa0860000 <-do_one_initcall
         modprobe-2786  [000] ....  3189.037876: 0xffffffffa086004d <-0xffffffffa086000f
         modprobe-2786  [000] ....  3189.037876: 0xffffffffa086010d <-0xffffffffa0860018
         modprobe-2786  [000] ....  3189.037877: 0xffffffffa086011a <-0xffffffffa0860021
         modprobe-2786  [000] ....  3189.037877: 0xffffffffa0860080 <-0xffffffffa086002a
         modprobe-2786  [000] ....  3189.039523: 0xffffffffa0860400 <-0xffffffffa0860033
         modprobe-2786  [000] ....  3189.039523: 0xffffffffa086038a <-0xffffffffa086041c
         modprobe-2786  [000] ....  3189.039591: 0xffffffffa086038a <-0xffffffffa0860436
         modprobe-2786  [000] ....  3189.039657: 0xffffffffa086038a <-0xffffffffa0860450
         modprobe-2786  [000] ....  3189.039719: 0xffffffffa0860127 <-0xffffffffa086003c
         modprobe-2786  [000] ....  3189.039742: snd_seq_create_kernel_client <-0xffffffffa08601f6

When the output is shown, the kallsyms for the module init functions have
already been freed, and the output of the trace can not convert them to
their function names.

Now this looks like this:

 # tracer: function
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
         modprobe-2463  [002] ....   174.243237: alsa_seq_init <-do_one_initcall
         modprobe-2463  [002] ....   174.243239: client_init_data <-alsa_seq_init
         modprobe-2463  [002] ....   174.243240: snd_sequencer_memory_init <-alsa_seq_init
         modprobe-2463  [002] ....   174.243240: snd_seq_queues_init <-alsa_seq_init
         modprobe-2463  [002] ....   174.243240: snd_sequencer_device_init <-alsa_seq_init
         modprobe-2463  [002] ....   174.244860: snd_seq_info_init <-alsa_seq_init
         modprobe-2463  [002] ....   174.244861: create_info_entry <-snd_seq_info_init
         modprobe-2463  [002] ....   174.244936: create_info_entry <-snd_seq_info_init
         modprobe-2463  [002] ....   174.245003: create_info_entry <-snd_seq_info_init
         modprobe-2463  [002] ....   174.245072: snd_seq_system_client_init <-alsa_seq_init
         modprobe-2463  [002] ....   174.245094: snd_seq_create_kernel_client <-snd_seq_system_client_init

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-10-05 17:57:33 -04:00
Masahiro Yamada
63b23e2cbc kernel/kallsyms.c: replace all_var with IS_ENABLED(CONFIG_KALLSYMS_ALL)
'all_var' looks like a variable, but is actually a macro.  Use
IS_ENABLED(CONFIG_KALLSYMS_ALL) for clarification.

Link: http://lkml.kernel.org/r/1497577591-3434-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10 16:32:34 -07:00
Daniel Borkmann
74451e66d5 bpf: make jited programs visible in traces
Long standing issue with JITed programs is that stack traces from
function tracing check whether a given address is kernel code
through {__,}kernel_text_address(), which checks for code in core
kernel, modules and dynamically allocated ftrace trampolines. But
what is still missing is BPF JITed programs (interpreted programs
are not an issue as __bpf_prog_run() will be attributed to them),
thus when a stack trace is triggered, the code walking the stack
won't see any of the JITed ones. The same for address correlation
done from user space via reading /proc/kallsyms. This is read by
tools like perf, but the latter is also useful for permanent live
tracing with eBPF itself in combination with stack maps when other
eBPF types are part of the callchain. See offwaketime example on
dumping stack from a map.

This work tries to tackle that issue by making the addresses and
symbols known to the kernel. The lookup from *kernel_text_address()
is implemented through a latched RB tree that can be read under
RCU in fast-path that is also shared for symbol/size/offset lookup
for a specific given address in kallsyms. The slow-path iteration
through all symbols in the seq file done via RCU list, which holds
a tiny fraction of all exported ksyms, usually below 0.1 percent.
Function symbols are exported as bpf_prog_<tag>, in order to aide
debugging and attribution. This facility is currently enabled for
root-only when bpf_jit_kallsyms is set to 1, and disabled if hardening
is active in any mode. The rationale behind this is that still a lot
of systems ship with world read permissions on kallsyms thus addresses
should not get suddenly exposed for them. If that situation gets
much better in future, we always have the option to change the
default on this. Likewise, unprivileged programs are not allowed
to add entries there either, but that is less of a concern as most
such programs types relevant in this context are for root-only anyway.
If enabled, call graphs and stack traces will then show a correct
attribution; one example is illustrated below, where the trace is
now visible in tooling such as perf script --kallsyms=/proc/kallsyms
and friends.

Before:

  7fff8166889d bpf_clone_redirect+0x80007f0020ed (/lib/modules/4.9.0-rc8+/build/vmlinux)
         f5d80 __sendmsg_nocancel+0xffff006451f1a007 (/usr/lib64/libc-2.18.so)

After:

  7fff816688b7 bpf_clone_redirect+0x80007f002107 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fffa0575728 bpf_prog_33c45a467c9e061a+0x8000600020fb (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fffa07ef1fc cls_bpf_classify+0x8000600020dc (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff81678b68 tc_classify+0x80007f002078 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8164d40b __netif_receive_skb_core+0x80007f0025fb (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8164d718 __netif_receive_skb+0x80007f002018 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8164e565 process_backlog+0x80007f002095 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8164dc71 net_rx_action+0x80007f002231 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff81767461 __softirqentry_text_start+0x80007f0020d1 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff817658ac do_softirq_own_stack+0x80007f00201c (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff810a2c20 do_softirq+0x80007f002050 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff810a2cb5 __local_bh_enable_ip+0x80007f002085 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8168d452 ip_finish_output2+0x80007f002152 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8168ea3d ip_finish_output+0x80007f00217d (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff8168f2af ip_output+0x80007f00203f (/lib/modules/4.9.0-rc8+/build/vmlinux)
  [...]
  7fff81005854 do_syscall_64+0x80007f002054 (/lib/modules/4.9.0-rc8+/build/vmlinux)
  7fff817649eb return_from_SYSCALL_64+0x80007f002000 (/lib/modules/4.9.0-rc8+/build/vmlinux)
         f5d80 __sendmsg_nocancel+0xffff01c484812007 (/usr/lib64/libc-2.18.so)

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17 13:40:05 -05:00
Ard Biesheuvel
2213e9a66b kallsyms: add support for relative offsets in kallsyms address table
Similar to how relative extables are implemented, it is possible to emit
the kallsyms table in such a way that it contains offsets relative to
some anchor point in the kernel image rather than absolute addresses.

On 64-bit architectures, it cuts the size of the kallsyms address table
in half, since offsets between kernel symbols can typically be expressed
in 32 bits.  This saves several hundreds of kilobytes of permanent
.rodata on average.  In addition, the kallsyms address table is no
longer subject to dynamic relocation when CONFIG_RELOCATABLE is in
effect, so the relocation work done after decompression now doesn't have
to do relocation updates for all these values.  This saves up to 24
bytes (i.e., the size of a ELF64 RELA relocation table entry) per value,
which easily adds up to a couple of megabytes of uncompressed __init
data on ppc64 or arm64.  Even if these relocation entries typically
compress well, the combined size reduction of 2.8 MB uncompressed for a
ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500
KB space saving in the compressed image.

Since it is useful for some architectures (like x86) to retain the
ability to emit absolute values as well, this patch also adds support
for capturing both absolute and relative values when
KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu
addresses as positive 32-bit values, and addresses relative to the
lowest encountered relative symbol as negative values, which are
subtracted from the runtime address of this base symbol to produce the
actual address.

Support for the above is enabled by default for all architectures except
IA-64 and Tile-GX, whose symbols are too far apart to capture in this
manner.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Rob Jones
0049f26ae0 kernel/kallsyms.c: use __seq_open_private()
Reduce boilerplate code by using __seq_open_private() instead of
seq_open() in kallsyms_open().

Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
Cc: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:16 +02:00
Namhyung Kim
b86280aa48 kernel/kallsyms.c: fix %pB when there's no symbol at the address
__sprint_symbol() should restore original address when kallsyms_lookup()
failed to find a symbol.  It's reported when dumpstack shows an address in
a dynamically allocated trampoline for ftrace.

  [ 1314.612287]  [<ffffffff81700312>] dump_stack+0x45/0x56
  [ 1314.612290]  [<ffffffff8125f5b0>] ? meminfo_proc_open+0x30/0x30
  [ 1314.612293]  [<ffffffffa080a494>] kpatch_ftrace_handler+0x14/0xf0 [kpatch]
  [ 1314.612306]  [<ffffffffa00160c4>] 0xffffffffa00160c3

You can see a difference in the hex address - c4 and c3.  Fix it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:18 -07:00
Gideon Israel Dsouza
52f5684c8e kernel: use macros from compiler.h instead of __attribute__((...))
To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs.  Eg: __weak for
__attribute__((weak)).  I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.

Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:11 -07:00
Chen Gang
e3f26752f0 kernel: kallsyms: memory override issue, need check destination buffer length
We don't export any symbols > 128 characters, but if we did then
  kallsyms_expand_symbol() would overflow the buffer handed to it.
  So we need check destination buffer length when copying.

  the related test:
    if we define an EXPORT function which name more than 128.
    will panic when call kallsyms_lookup_name by init_kprobes on booting.
    after check the length (provide this patch), it is ok.

  Implementaion:
    add additional destination buffer length parameter (maxlen)
    if uncompressed string is too long (>= maxlen), it will be truncated.
    not check the parameters whether valid, since it is a static function.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-15 15:17:26 +09:30
Stephen Boyd
4796dd200d vsprintf: fix %ps on non symbols when using kallsyms
Using %ps in a printk format will sometimes fail silently and print the
empty string if the address passed in does not match a symbol that
kallsyms knows about.  But using %pS will fall back to printing the full
address if kallsyms can't find the symbol.  Make %ps act the same as %pS
by falling back to printing the address.

While we're here also make %ps print the module that a symbol comes from
so that it matches what %pS already does.  Take this simple function for
example (in a module):

	static void test_printk(void)
	{
		int test;
		pr_info("with pS: %pS\n", &test);
		pr_info("with ps: %ps\n", &test);
	}

Before this patch:

 with pS: 0xdff7df44
 with ps:

After this patch:

 with pS: 0xdff7df44
 with ps: 0xdff7df44

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:32 -07:00
Linus Torvalds
94df491c4a Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix WARN_ON() test for UP
  WARN_ON_SMP(): Allow use in if() statements on UP
  x86, dumpstack: Use %pB format specifier for stack trace
  vsprintf: Introduce %pB format specifier
  lockdep: Remove unused 'factor' variable from lockdep_stats_show()
2011-03-25 17:52:22 -07:00
Namhyung Kim
0f77a8d378 vsprintf: Introduce %pB format specifier
The %pB format specifier is for stack backtrace. Its handler
sprint_backtrace() does symbol lookup using (address-1) to
ensure the address will not point outside of the function.

If there is a tail-call to the function marked "noreturn",
gcc optimized out the code after the call then causes saved
return address points outside of the function (i.e. the start
of the next function), so pollutes call trace somewhat.

This patch adds the %pB printk mechanism that allows architecture
call-trace printout functions to improve backtrace printouts.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
LKML-Reference: <1300934550-21394-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-24 08:36:10 +01:00
Linus Torvalds
b81a618dcd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  deal with races in /proc/*/{syscall,stack,personality}
  proc: enable writing to /proc/pid/mem
  proc: make check_mem_permission() return an mm_struct on success
  proc: hold cred_guard_mutex in check_mem_permission()
  proc: disable mem_write after exec
  mm: implement access_remote_vm
  mm: factor out main logic of access_process_vm
  mm: use mm_struct to resolve gate vma's in __get_user_pages
  mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
  mm: arch: make in_gate_area take an mm_struct instead of a task_struct
  mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
  x86: mark associated mm when running a task in 32 bit compatibility mode
  x86: add context tag to mark mm when running a task in 32-bit compatibility mode
  auxv: require the target to be tracable (or yourself)
  close race in /proc/*/environ
  report errors in /proc/*/*map* sanely
  pagemap: close races with suid execve
  make sessionid permissions in /proc/*/task/* match those in /proc/*
  fix leaks in path_lookupat()

Fix up trivial conflicts in fs/proc/base.c
2011-03-23 20:51:42 -07:00
Stephen Wilson
cae5d39032 mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
Now that gate vma's are referenced with respect to a particular mm and not a
particular task it only makes sense to propagate the change to this predicate as
well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-23 16:36:55 -04:00
Kees Cook
9f36e2c448 printk: use %pK for /proc/kallsyms and /proc/modules
In an effort to reduce kernel address leaks that might be used to help
target kernel privilege escalation exploits, this patch uses %pK when
displaying addresses in /proc/kallsyms, /proc/modules, and
/sys/module/*/sections/*.

Note that this changes %x to %p, so some legitimately 0 values in
/proc/kallsyms would have changed from 00000000 to "(null)".  To avoid
this, "(null)" is not used when using the "K" format.  Anything that was
already successfully parsing "(null)" in addition to full hex digits
should have no problem with this change.  (Thanks to Joe Perches for the
suggestion.) Due to the %x to %p, "void *" casts are needed since these
addresses are already "unsigned long" everywhere internally, due to their
starting life as ELF section offsets.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Cc: Eugene Teo <eugene@redhat.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:12 -07:00
Linus Torvalds
33e0d57f5d Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"
This reverts commit 59365d136d.

It turns out that this can break certain existing user land setups.
Quoth Sarah Sharp:

 "On Wednesday, I updated my branch to commit 460781b from linus' tree,
  and my box would not boot.  klogd segfaulted, which stalled the whole
  system.

  At first I thought it actually hung the box, but it continued booting
  after 5 minutes, and I was able to log in.  It dropped back to the
  text console instead of the graphical bootup display for that period
  of time.  dmesg surprisingly still works.  I've bisected the problem
  down to this commit (commit 59365d136d)

  The box is running klogd 1.5.5ubuntu3 (from Jaunty).  Yes, I know
  that's old.  I read the bit in the commit about changing the
  permissions of kallsyms after boot, but if I can't boot that doesn't
  help."

So let's just keep the old default, and encourage distributions to do
the "chmod -r /proc/kallsyms" in their bootup scripts.  This is not
worth a kernel option to change default behavior, since it's so easily
done in user space.

Reported-and-bisected-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-19 11:54:40 -08:00
Marcus Meissner
59365d136d kernel: make /proc/kallsyms mode 400 to reduce ease of attacking
Making /proc/kallsyms readable only for root by default makes it
slightly harder for attackers to write generic kernel exploits by
removing one source of knowledge where things are in the kernel.

This is the second submit, discussion happened on this on first submit
and mostly concerned that this is just one hole of the sieve ...  but
one of the bigger ones.

Changing the permissions of at least System.map and vmlinux is also
required to fix the same set, but a packaging issue.

Target of this starter patch and follow ups is removing any kind of
kernel space address information leak from the kernel.

[ Side note: the default of root-only reading is the "safe" value, and
  it's easy enough to then override at any time after boot.  The /proc
  filesystem allows root to change the permissions with a regular
  chmod, so you can "revert" this at run-time by simply doing

    chmod og+r /proc/kallsyms

  as root if you really want regular users to see the kernel symbols.
  It does help some tools like "perf" figure them out without any
  setup, so it may well make sense in some situations.  - Linus ]

Signed-off-by: Marcus Meissner <meissner@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16 19:06:01 -08:00
Jason Wessel
67fc4e0cb9 kdb: core for kgdb back end (2 of 2)
This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...

CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
2010-05-20 21:04:21 -05:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Frederic Weisbecker
f60d24d2ad hw-breakpoints: Fix broken hw-breakpoint sample module
The hw-breakpoint sample module has been broken during the
hw-breakpoint internals refactoring. Propagate the changes
to it.

Reported-by: "K. Prasad" <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-11-10 11:23:29 +01:00
Mike Frysinger
128e8db38e kallsyms: use new arch_is_kernel_text()
This allows kallsyms to locate symbols that are in arch-specific text
sections (such as text in Blackfin on-chip SRAM regions).

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:30 -07:00
Manish Katiyar
ad6ccfad6f kernel/kallsyms.c: replace deprecated __initcall with device_initcall and fix whitespace
Fix coding style whitespace issues and replace __initcall with
device_initcall.  Fixed multi-line comments as per coding style.

Errors as reported by checkpatch.pl :-
Before:
total: 14 errors, 14 warnings, 487 lines checked
After :
total: 0 errors, 8 warnings, 507 lines checked

Compile tested binary verified as :-
Before:
 text    data     bss     dec     hex filename
 2405       4       0    2409     969 kernel/kallsyms.o
After :
 text     data     bss     dec     hex filename
 2405       4       0    2409     969 kernel/kallsyms.o

Signed-off-by: Manish Katiyar <mkatiyar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-06-09 22:37:52 +02:00
Anders Kaseorg
75a66614db Ksplice: Add functions for walking kallsyms symbols
Impact: New API

kallsyms_lookup_name only returns the first match that it finds.  Ksplice
needs information about all symbols with a given name in order to correctly
resolve local symbols.

kallsyms_on_each_symbol provides a generic mechanism for iterating over the
kallsyms table.

Cc: Jeff Arnold <jbarnold@mit.edu>
Cc: Tim Abbott <tabbott@mit.edu>
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-31 13:05:32 +10:30
Sam Ravnborg
2ea038917b Revert "kbuild: strip generated symbols from *.ko"
This reverts commit ad7a953c52.

And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL")
            9bb482476c

These stripping patches has caused a set of issues:

1) People have reported compatibility issues with binutils due to
   lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2
   Reported by: Wenji
2) ccache and distcc no longer works as expeced
   Reported by: Ted, Roland, + others
3) The installed modules increased a lot in size
   Reported by: Ted, Davej + others

Reported-by: Wenji Huang <wenji.huang@oracle.com>
Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-01-14 21:38:20 +01:00
Jan Beulich
9bb482476c allow stripping of generated symbols under CONFIG_KALLSYMS_ALL
Building upon parts of the module stripping patch, this patch
introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
kernels I tested with.

The patch also does away with the need to special case the kallsyms-
internal symbols by making them available even in the first linking
stage.

While it is a generated file, the patch includes the changes to
scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
here is.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-19 22:47:10 +01:00
Hugh Dickins
966c8c12dc sprint_symbol(): use less stack
sprint_symbol(), itself used when dumping stacks, has been wasting 128
bytes of stack: lookup the symbol directly into the buffer supplied by the
caller, instead of using a locally declared namebuf.

I believe the name != buffer strcpy() is obsolete: the design here dates
from when module symbol lookup pointed into a supposedly const but sadly
volatile table; nowadays it copies, but an uncalled strcpy() looks better
here than the risk of a recursive BUG_ON().

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-19 18:49:58 -08:00
WANG Cong
7968b3d9a6 kernel/kallsyms.c: fix double return
Commit 6dd06c9fbe ("module: make
module_address_lookup safe") introduced double returns in the function
kallsyms_lookup(), it's weird.  The second one should be removed.

Signed-off-by: WANG Cong <wangcong@zeuux.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:32 -07:00
Vegard Nossum
2fc9c4e18f kallsyms: fix potential overflow in binary search
This will probably never trigger... but it won't hurt to be careful.

http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Joshua Bloch <jjb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:27 -07:00
Denis V. Lunev
c33fff0afb kernel: use non-racy method for proc entries creation
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:22 -07:00
Robin Getz
a3b81113fb remove support for un-needed _extratext section
When passing a zero address to kallsyms_lookup(), the kernel thought it was
a valid kernel address, even if it is not.  This is because is_ksym_addr()
called is_kernel_extratext() and checked against labels that don't exist on
many archs (which default as zero).  Since PPC was the only kernel which
defines _extra_text, (in 2005), and no longer needs it, this patch removes
_extra_text support.

For some history (provided by Jon):
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019734.html
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019736.html
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019751.html

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jon Loeliger <jdl@freescale.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:01 -08:00
Rusty Russell
6dd06c9fbe module: make module_address_lookup safe
module_address_lookup releases preemption then returns a pointer into
the module space.  The only user (kallsyms) copies the result, so just
do that under the preempt disable.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-29 17:13:23 +11:00
David Howells
9e6c1e6333 FRV: fix the extern declaration of kallsyms_num_syms
Fix the extern declaration of kallsyms_num_syms to indicate that the symbol
does not reside in the small-data storage space, and so may not be accessed
relative to the small data base register.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:54 -08:00
Tejun Heo
9281acea6a kallsyms: make KSYM_NAME_LEN include space for trailing '\0'
KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer.  This is nonsense and error-prone.  Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.

This patch increments KSYM_NAME_LEN by one and updates code accordingly.

* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
  is fixed.

* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
  MODULE_NAME_LEN was treated as if it didn't include space for the
  trailing '\0'.  Fix it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00