Changes in 5.15.47
pcmcia: db1xxx_ss: restrict to MIPS_DB1XXX boards
staging: greybus: codecs: fix type confusion of list iterator variable
iio: adc: ad7124: Remove shift from scan_type
lkdtm/bugs: Check for the NULL pointer after calling kmalloc
lkdtm/bugs: Don't expect thread termination without CONFIG_UBSAN_TRAP
tty: goldfish: Use tty_port_destroy() to destroy port
tty: serial: owl: Fix missing clk_disable_unprepare() in owl_uart_probe
tty: n_tty: Restore EOF push handling behavior
serial: 8250_aspeed_vuart: Fix potential NULL dereference in aspeed_vuart_probe
tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_simple_get
remoteproc: imx_rproc: Ignore create mem entry for resource table
usb: usbip: fix a refcount leak in stub_probe()
usb: usbip: add missing device lock on tweak configuration cmd
USB: storage: karma: fix rio_karma_init return
usb: musb: Fix missing of_node_put() in omap2430_probe
staging: fieldbus: Fix the error handling path in anybuss_host_common_probe()
pwm: lp3943: Fix duty calculation in case period was clamped
pwm: raspberrypi-poe: Fix endianness in firmware struct
rpmsg: qcom_smd: Fix irq_of_parse_and_map() return value
usb: dwc3: gadget: Replace list_for_each_entry_safe() if using giveback
usb: dwc3: pci: Fix pm_runtime_get_sync() error checking
misc: fastrpc: fix an incorrect NULL check on list iterator
firmware: stratix10-svc: fix a missing check on list iterator
usb: typec: mux: Check dev_set_name() return value
rpmsg: virtio: Fix possible double free in rpmsg_probe()
rpmsg: virtio: Fix possible double free in rpmsg_virtio_add_ctrl_dev()
rpmsg: virtio: Fix the unregistration of the device rpmsg_ctrl
iio: adc: stmpe-adc: Fix wait_for_completion_timeout return value check
iio: proximity: vl53l0x: Fix return value check of wait_for_completion_timeout
iio: adc: sc27xx: fix read big scale voltage not right
iio: adc: sc27xx: Fine tune the scale calibration values
rpmsg: qcom_smd: Fix returning 0 if irq_of_parse_and_map() fails
pvpanic: Fix typos in the comments
misc/pvpanic: Convert regular spinlock into trylock on panic path
phy: qcom-qmp: fix pipe-clock imbalance on power-on failure
power: supply: axp288_fuel_gauge: Drop BIOS version check from "T3 MRD" DMI quirk
serial: sifive: Report actual baud base rather than fixed 115200
export: fix string handling of namespace in EXPORT_SYMBOL_NS
soundwire: intel: prevent pm_runtime resume prior to system suspend
coresight: cpu-debug: Replace mutex with mutex_trylock on panic notifier
ksmbd: fix reference count leak in smb_check_perm_dacl()
extcon: ptn5150: Add queue work sync before driver release
soc: rockchip: Fix refcount leak in rockchip_grf_init
clocksource/drivers/riscv: Events are stopped during CPU suspend
ARM: dts: aspeed: ast2600-evb: Enable RX delay for MAC0/MAC1
rtc: mt6397: check return value after calling platform_get_resource()
rtc: ftrtc010: Use platform_get_irq() to get the interrupt
rtc: ftrtc010: Fix error handling in ftrtc010_rtc_probe
staging: r8188eu: add check for kzalloc
tty: n_gsm: Don't ignore write return value in gsmld_output()
tty: n_gsm: Fix packet data hex dump output
serial: meson: acquire port->lock in startup()
serial: 8250_fintek: Check SER_RS485_RTS_* only with RS485
serial: cpm_uart: Fix build error without CONFIG_SERIAL_CPM_CONSOLE
serial: digicolor-usart: Don't allow CS5-6
serial: rda-uart: Don't allow CS5-6
serial: txx9: Don't allow CS5-6
serial: sh-sci: Don't allow CS5-6
serial: sifive: Sanitize CSIZE and c_iflag
serial: st-asc: Sanitize CSIZE and correct PARENB for CS7
serial: stm32-usart: Correct CSIZE, bits, and parity
firmware: dmi-sysfs: Fix memory leak in dmi_sysfs_register_handle
bus: ti-sysc: Fix warnings for unbind for serial
driver: base: fix UAF when driver_attach failed
driver core: fix deadlock in __device_attach
watchdog: rti-wdt: Fix pm_runtime_get_sync() error checking
watchdog: ts4800_wdt: Fix refcount leak in ts4800_wdt_probe
blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx
ASoC: fsl_sai: Fix FSL_SAI_xDR/xFR definition
clocksource/drivers/oxnas-rps: Fix irq_of_parse_and_map() return value
s390/crypto: fix scatterwalk_unmap() callers in AES-GCM
net: sched: fixed barrier to prevent skbuff sticking in qdisc backlog
net: ethernet: mtk_eth_soc: out of bounds read in mtk_hwlro_get_fdir_entry()
net: ethernet: ti: am65-cpsw-nuss: Fix some refcount leaks
net: dsa: mv88e6xxx: Fix refcount leak in mv88e6xxx_mdios_register
modpost: fix removing numeric suffixes
jffs2: fix memory leak in jffs2_do_fill_super
ubi: fastmap: Fix high cpu usage of ubi_bgt by making sure wl_pool not empty
ubi: ubi_create_volume: Fix use-after-free when volume creation failed
selftests/bpf: fix selftest after random: Urandom_read tracepoint removal
selftests/bpf: fix stacktrace_build_id with missing kprobe/urandom_read
bpf: Fix probe read error in ___bpf_prog_run()
block: take destination bvec offsets into account in bio_copy_data_iter
riscv: read-only pages should not be writable
net/smc: fixes for converting from "struct smc_cdc_tx_pend **" to "struct smc_wr_tx_pend_priv *"
tcp: add accessors to read/set tp->snd_cwnd
nfp: only report pause frame configuration for physical device
sfc: fix considering that all channels have TX queues
sfc: fix wrong tx channel offset with efx_separate_tx_channels
block: make bioset_exit() fully resilient against being called twice
vdpa: Fix error logic in vdpa_nl_cmd_dev_get_doit
virtio: pci: Fix an error handling path in vp_modern_probe()
net/mlx5: Don't use already freed action pointer
net/mlx5e: TC NIC mode, fix tc chains miss table
net/mlx5: CT: Fix header-rewrite re-use for tupels
net/mlx5: correct ECE offset in query qp output
net/mlx5e: Update netdev features after changing XDP state
net: sched: add barrier to fix packet stuck problem for lockless qdisc
tcp: tcp_rtx_synack() can be called from process context
vdpa: ifcvf: set pci driver data in probe
octeontx2-af: fix error code in is_valid_offset()
s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flag
regulator: mt6315-regulator: fix invalid allowed mode
gpio: pca953x: use the correct register address to do regcache sync
afs: Fix infinite loop found by xfstest generic/676
scsi: sd: Fix potential NULL pointer dereference
tipc: check attribute length for bearer name
driver core: Fix wait_for_device_probe() & deferred_probe_timeout interaction
perf c2c: Fix sorting in percent_rmt_hitm_cmp()
dmaengine: idxd: set DMA_INTERRUPT cap bit
mips: cpc: Fix refcount leak in mips_cpc_default_phys_base
bootconfig: Make the bootconfig.o as a normal object file
tracing: Make tp_printk work on syscall tracepoints
tracing: Fix sleeping function called from invalid context on RT kernel
tracing: Avoid adding tracer option before update_tracer_options
iommu/arm-smmu: fix possible null-ptr-deref in arm_smmu_device_probe()
iommu/arm-smmu-v3: check return value after calling platform_get_resource()
f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
i2c: cadence: Increase timeout per message if necessary
m68knommu: set ZERO_PAGE() to the allocated zeroed page
m68knommu: fix undefined reference to `_init_sp'
dmaengine: zynqmp_dma: In struct zynqmp_dma_chan fix desc_size data type
NFSv4: Don't hold the layoutget locks across multiple RPC calls
video: fbdev: hyperv_fb: Allow resolutions with size > 64 MB for Gen1
video: fbdev: pxa3xx-gcu: release the resources correctly in pxa3xx_gcu_probe/remove()
RISC-V: use memcpy for kexec_file mode
m68knommu: fix undefined reference to `mach_get_rtc_pll'
f2fs: fix to tag gcing flag on page during file defragment
xprtrdma: treat all calls not a bcall when bc_serv is NULL
drm/bridge: sn65dsi83: Fix an error handling path in sn65dsi83_probe()
drm/bridge: ti-sn65dsi83: Handle dsi_lanes == 0 as invalid
netfilter: nat: really support inet nat without l3 address
netfilter: nf_tables: use kfree_rcu(ptr, rcu) to release hooks in clean_net path
netfilter: nf_tables: delete flowtable hooks via transaction list
powerpc/kasan: Force thread size increase with KASAN
SUNRPC: Trap RDMA segment overflows
netfilter: nf_tables: always initialize flowtable hook list in transaction
ata: pata_octeon_cf: Fix refcount leak in octeon_cf_probe
netfilter: nf_tables: release new hooks on unsupported flowtable flags
netfilter: nf_tables: memleak flow rule from commit path
netfilter: nf_tables: bail out early if hardware offload is not supported
xen: unexport __init-annotated xen_xlate_map_ballooned_pages()
stmmac: intel: Fix an error handling path in intel_eth_pci_probe()
af_unix: Fix a data-race in unix_dgram_peer_wake_me().
bpf, arm64: Clear prog->jited_len along prog->jited
net: dsa: lantiq_gswip: Fix refcount leak in gswip_gphy_fw_list
net/mlx4_en: Fix wrong return value on ioctl EEPROM query failure
i40e: xsk: Move tmp desc array from driver to pool
xsk: Fix handling of invalid descriptors in XSK TX batching API
SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()
net: mdio: unexport __init-annotated mdio_bus_init()
net: xfrm: unexport __init-annotated xfrm4_protocol_init()
net: ipv6: unexport __init-annotated seg6_hmac_init()
net/mlx5: Lag, filter non compatible devices
net/mlx5: Fix mlx5_get_next_dev() peer device matching
net/mlx5: Rearm the FW tracer after each tracer event
net/mlx5: fs, fail conflicting actions
ip_gre: test csum_start instead of transport header
net: altera: Fix refcount leak in altera_tse_mdio_create
net: dsa: mv88e6xxx: use BMSR_ANEGCOMPLETE bit for filling an_complete
tcp: use alloc_large_system_hash() to allocate table_perturb
drm: imx: fix compiler warning with gcc-12
nfp: flower: restructure flow-key for gre+vlan combination
iov_iter: Fix iter_xarray_get_pages{,_alloc}()
iio: dummy: iio_simple_dummy: check the return value of kstrdup()
staging: rtl8712: fix a potential memory leak in r871xu_drv_init()
iio: st_sensors: Add a local lock for protecting odr
lkdtm/usercopy: Expand size of "out of frame" object
drivers: staging: rtl8723bs: Fix deadlock in rtw_surveydone_event_callback()
drivers: staging: rtl8192bs: Fix deadlock in rtw_joinbss_event_prehandle()
tty: synclink_gt: Fix null-pointer-dereference in slgt_clean()
tty: Fix a possible resource leak in icom_probe
thunderbolt: Use different lane for second DisplayPort tunnel
drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()
drivers: staging: rtl8192e: Fix deadlock in rtllib_beacons_stop()
USB: host: isp116x: check return value after calling platform_get_resource()
drivers: tty: serial: Fix deadlock in sa1100_set_termios()
drivers: usb: host: Fix deadlock in oxu_bus_suspend()
USB: hcd-pci: Fully suspend across freeze/thaw cycle
char: xillybus: fix a refcount leak in cleanup_dev()
sysrq: do not omit current cpu when showing backtrace of all active CPUs
usb: dwc2: gadget: don't reset gadget's driver->bus
soundwire: qcom: adjust autoenumeration timeout
misc: rtsx: set NULL intfdata when probe fails
extcon: Fix extcon_get_extcon_dev() error handling
extcon: Modify extcon device to be created after driver data is set
clocksource/drivers/sp804: Avoid error on multiple instances
staging: rtl8712: fix uninit-value in usb_read8() and friends
staging: rtl8712: fix uninit-value in r871xu_drv_init()
serial: msm_serial: disable interrupts in __msm_console_write()
kernfs: Separate kernfs_pr_cont_buf and rename_lock.
watchdog: wdat_wdt: Stop watchdog when rebooting the system
md: protect md_unregister_thread from reentrancy
scsi: myrb: Fix up null pointer access on myrb_cleanup()
Revert "net: af_key: add check for pfkey_broadcast in function pfkey_process"
ceph: allow ceph.dir.rctime xattr to be updatable
ceph: flush the mdlog for filesystem sync
drm/amd/display: Check if modulo is 0 before dividing.
drm/radeon: fix a possible null pointer dereference
drm/amd/pm: Fix missing thermal throttler status
um: line: Use separate IRQs per line
modpost: fix undefined behavior of is_arm_mapping_symbol()
x86/cpu: Elide KCSAN for cpu_has() and friends
jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds
nbd: call genl_unregister_family() first in nbd_cleanup()
nbd: fix race between nbd_alloc_config() and module removal
nbd: fix io hung while disconnecting device
s390/gmap: voluntarily schedule during key setting
cifs: version operations for smb20 unneeded when legacy support disabled
drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate
nodemask: Fix return values to be unsigned
vringh: Fix loop descriptors check in the indirect cases
scripts/gdb: change kernel config dumping method
ALSA: usb-audio: Skip generic sync EP parse for secondary EP
ALSA: usb-audio: Set up (implicit) sync for Saffire 6
ALSA: hda/conexant - Fix loopback issue with CX20632
ALSA: hda/realtek: Fix for quirk to enable speaker output on the Lenovo Yoga DuetITL 2021
ALSA: hda/realtek: Add quirk for HP Dev One
cifs: return errors during session setup during reconnects
cifs: fix reconnect on smb3 mount types
KEYS: trusted: tpm2: Fix migratable logic
ata: libata-transport: fix {dma|pio|xfer}_mode sysfs files
mmc: block: Fix CQE recovery reset success
net: phy: dp83867: retrigger SGMII AN when link change
net: openvswitch: fix misuse of the cached connection on tuple changes
writeback: Fix inode->i_io_list not be protected by inode->i_lock error
nfc: st21nfca: fix incorrect validating logic in EVT_TRANSACTION
nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling
nfc: st21nfca: fix incorrect sizing calculations in EVT_TRANSACTION
ixgbe: fix bcast packets Rx on VF after promisc removal
ixgbe: fix unexpected VLAN Rx in promisc mode on VF
Input: bcm5974 - set missing URB_NO_TRANSFER_DMA_MAP urb flag
vduse: Fix NULL pointer dereference on sysfs access
powerpc: Don't select HAVE_IRQ_EXIT_ON_IRQ_STACK
drm/bridge: analogix_dp: Support PSR-exit to disable transition
drm/atomic: Force bridge self-refresh-exit on CRTC switch
drm/amdgpu: update VCN codec support for Yellow Carp
powerpc/32: Fix overread/overwrite of thread_struct via ptrace
powerpc/mm: Switch obsolete dssall to .long
drm/ast: Create threshold values for AST2600
random: avoid checking crng_ready() twice in random_init()
random: mark bootloader randomness code as __init
random: account for arch randomness in bits
md/raid0: Ignore RAID0 layout if the second zone has only one device
net/sched: act_police: more accurate MTU policing
PCI: qcom: Fix pipe clock imbalance
zonefs: fix handling of explicit_open option on mount
iov_iter: fix build issue due to possible type mis-match
dmaengine: idxd: add missing callback function to support DMA_INTERRUPT
tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd
xsk: Fix possible crash when multiple sockets are created
Linux 5.15.47
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I40e7672edf2bd713fee775919d062e2934d9103d
The CRC calculation done by genksyms is triggered when the parser hits
EXPORT_SYMBOL*() macros. At this point, genksyms recursively expands the
types, and uses that as the input for the CRC calculation. In the case
of forward-declared structs, the type expands to 'UNKNOWN'. Next, the
result of the expansion of each type is cached, and is re-used when/if
the same type is seen again for another exported symbol in the file.
Unfortunately, this can cause CRC 'stability' issues when a struct
definition becomes visible in the middle of a C file. For example, let's
assume code with the following pattern:
struct foo;
int bar(struct foo *arg)
{
/* Do work ... */
}
EXPORT_SYMBOL_GPL(bar);
/* This contains struct foo's definition */
#include "foo.h"
int baz(struct foo *arg)
{
/* Do more work ... */
}
EXPORT_SYMBOL_GPL(baz);
Here, baz's CRC will be computed using the expansion of struct foo that
was cached after bar's CRC calculation ('UNKOWN' here). But if
EXPORT_SYMBOL_GPL(bar) is removed from the file (because of e.g. symbol
trimming using CONFIG_TRIM_UNUSED_KSYMS), struct foo will be expanded
late, during baz's CRC calculation, which now has visibility over the
full struct definition, hence resulting in a different CRC for baz.
This can cause annoying issues for distro kernel (such as the Android
Generic Kernel Image) which use CONFIG_UNUSED_KSYMS_WHITELIST. Indeed,
as per the above, adding a symbol to the whitelist can change the CRC of
symbols that are already kept exported. As such, modules built against a
kernel with a trimmed ABI may not load against the same kernel built
with an extended whitelist, even though they are still strictly binary
compatible. While rebuilding the modules would obviously solve the
issue, I believe this classifies as an odd genksyms corner case, and it
gets in the way of kernel updates in the GKI context.
To work around the issue, make sure to keep issuing the
__GENKSYMS_EXPORT_SYMBOL macros for all trimmed symbols, hence making
the genksyms parsing insensitive to symbol trimming.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210408180105.2496212-1-qperret@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The CRC calculation done by genksyms is triggered when the parser hits
EXPORT_SYMBOL*() macros. At this point, genksyms recursively expands the
types, and uses that as the input for the CRC calculation. In the case
of forward-declared structs, the type expands to 'UNKNOWN'. Next, the
result of the expansion of each type is cached, and is re-used when/if
the same type is seen again for another exported symbol in the file.
Unfortunately, this can cause CRC 'stability' issues when a struct
definition becomes visible in the middle of a C file. For example, let's
assume code with the following pattern:
struct foo;
int bar(struct foo *arg)
{
/* Do work ... */
}
EXPORT_SYMBOL_GPL(bar);
/* This contains struct foo's definition */
#include "foo.h"
int baz(struct foo *arg)
{
/* Do more work ... */
}
EXPORT_SYMBOL_GPL(baz);
Here, baz's CRC will be computed using the expansion of struct foo that
was cached after bar's CRC calculation ('UNKOWN' here). But if
EXPORT_SYMBOL_GPL(bar) is removed from the file (because of e.g. symbol
trimming using CONFIG_TRIM_UNUSED_KSYMS), struct foo will be expanded
late, during baz's CRC calculation, which now has visibility over the
full struct definition, hence resulting in a different CRC for baz.
This can cause annoying issues for distro kernel (such as the Android
Generic Kernel Image) which use CONFIG_UNUSED_KSYMS_WHITELIST. Indeed,
as per the above, adding a symbol to the whitelist can change the CRC of
symbols that are already kept exported. As such, modules built against a
kernel with a trimmed ABI may not load against the same kernel built
with an extended whitelist, even though they are still strictly binary
compatible. While rebuilding the modules would obviously solve the
issue, I believe this classifies as an odd genksyms corner case, and it
gets in the way of kernel updates in the GKI context.
To work around the issue, make sure to keep issuing the
__GENKSYMS_EXPORT_SYMBOL macros for all trimmed symbols, hence making
the genksyms parsing insensitive to symbol trimming.
Bug: 184275771
Bug: 167230325
Signed-off-by: Quentin Perret <qperret@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210408180105.2496212-1-qperret@google.com
Change-Id: Id94085d446d5648943d4fe4f79e3177bc4f98093
Steps on the way to 5.12-rc1
Resolves conflicts in:
include/linux/module.h
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I44772d65a5d6b1c5f4c33905554092c2cdc5b210
EXPORT_UNUSED_SYMBOL* is not actually used anywhere. Remove the
unused functionality as we generally just remove unused code anyway.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
As far as I can tell this has never been used at all, and certainly
not any time recently.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Trimming non-whitelisted symbols from modules will be useful once we
introduce GKI modules, but in the meantime it causes pain downstream for
out-of-tree modules as vendors will have to whitelist the symbols they
need.
The right solution would be to apply the trimming or not to a module
based on an explicit list of GKI modules, but as we currently don't have
any (nor we have a good way to differentiate them in the kernel build
system), let's simply disable the trimming for all modules altogether,
and get things unblocked for GKI 1.0.
Bug: 148277666
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I2513d85c46eefc62c59883b724b6153dd27b3671
Commit c3a6cf19e6 ("export: avoid code duplication in
include/linux/export.h") refactors export.h quite nicely, but introduces
a slight increase in memory usage due to using the empty string ""
instead of NULL to indicate that an exported symbol has no namespace. As
mentioned in that commit, this meant an increase of 1 byte per exported
symbol without a namespace. For example, if a kernel configuration has
about 10k exported symbols, this would mean that the size of
__ksymtab_strings would increase by roughly 10kB.
We can alleviate this situation by utilizing the SHF_MERGE and
SHF_STRING section flags. SHF_MERGE|SHF_STRING indicate to the linker
that the data in the section are null-terminated strings that can be
merged to eliminate duplication. More specifically, from the binutils
documentation - "for sections with both M and S, a string which is a
suffix of a larger string is considered a duplicate. Thus "def" will be
merged with "abcdef"; A reference to the first "def" will be changed to
a reference to "abcdef"+3". Thus, all the empty strings would be merged
as well as any strings that can be merged according to the cited method
above. For example, "memset" and "__memset" would be merged to just
"__memset" in __ksymtab_strings.
As of v5.4-rc5, the following statistics were gathered with x86
defconfig with approximately 10.7k exported symbols.
Size of __ksymtab_strings in vmlinux:
-------------------------------------
v5.4-rc5: 213834 bytes
v5.4-rc5 with commit c3a6cf19e6: 224455 bytes
v5.4-rc5 with this patch: 205759 bytes
So, we already see memory savings of ~8kB compared to vanilla -rc5 and
savings of nearly 18.7kB compared to -rc5 with commit c3a6cf19e6 on top.
Unfortunately, as of this writing, strings will not get deduplicated for
kernel modules, as ld does not do the deduplication for
SHF_MERGE|SHF_STRINGS sections for relocatable files (ld -r), which
kernel modules are. A patch for ld is currently being worked on to
hopefully allow for string deduplication in relocatable files in the
future.
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Pull modules updates from Jessica Yu:
"Summary of modules changes for the 5.5 merge window:
- Refactor include/linux/export.h and remove code duplication between
EXPORT_SYMBOL and EXPORT_SYMBOL_NS to make it more readable.
The most notable change is that no namespace is represented by an
empty string "" rather than NULL.
- Fix a module load/unload race where waiter(s) trying to load the
same module weren't being woken up when a module finally goes away"
* tag 'modules-for-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
kernel/module.c: wakeup processes in module_wq on module unload
moduleparam: fix parameter description mismatch
export: avoid code duplication in include/linux/export.h
Commit b24413180f ("License cleanup: add SPDX GPL-2.0 license
identifier to files with no license") took care of a lot of files
without any license information.
These headers were not processed by the tool perhaps because they
contain "GPL" in the code.
I do not see any license boilerplate in them, so they fall back to
GPL version 2 only, which is the project default.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/r/20191018045053.8424-1-yamada.masahiro@socionext.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/linux/export.h has lots of code duplication between
EXPORT_SYMBOL and EXPORT_SYMBOL_NS.
To improve the maintainability and readability, unify the
implementation.
When the symbol has no namespace, pass the empty string "" to
the 'ns' parameter.
The drawback of this change is, it grows the code size.
When the symbol has no namespace, sym->namespace was previously
NULL, but it is now an empty string "". So, it increases 1 byte
for every no namespace EXPORT_SYMBOL.
A typical kernel configuration has 10K exported symbols, so it
increases 10KB in rough estimation.
I did not come up with a good idea to refactor it without increasing
the code size.
I am not sure how big a deal it is, but at least include/linux/export.h
looks nicer.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[maennich: rebase on top of 3 fixes for the namespace feature]
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The introduction of Symbol Namespaces changed the naming schema of the
__ksymtab entries from __kysmtab__symbol to __ksymtab_NAMESPACE.symbol.
That caused some breakages in tools that depend on the name layout in
either the binaries(vmlinux,*.ko) or in System.map. E.g. kmod's depmod
would not be able to read System.map without a patch to support symbol
namespaces. A warning reported by depmod for namespaced symbols would
look like
depmod: WARNING: [...]/uas.ko needs unknown symbol usb_stor_adjust_quirks
In order to address this issue, revert to the original naming scheme and
rather read the __kstrtabns_<symbol> entries and their corresponding
values from __ksymtab_strings to update the namespace values for
symbols. After having read all symbols and handled them in
handle_modversions(), the symbols are created. In a second pass, read
the __kstrtabns_ entries and update the namespaces accordingly.
Fixes: 8651ec01da ("module: add support for symbol namespaces.")
Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The module namespace produces __strtab_ns_<sym> symbols to store
namespace strings, but it does not guarantee the name uniqueness.
This is a potential problem because we have exported symbols starting
with "ns_".
For example, kernel/capability.c exports the following symbols:
EXPORT_SYMBOL(ns_capable);
EXPORT_SYMBOL(capable);
Assume a situation where those are converted as follows:
EXPORT_SYMBOL_NS(ns_capable, some_namespace);
EXPORT_SYMBOL_NS(capable, some_namespace);
The former expands to "__kstrtab_ns_capable" and "__kstrtab_ns_ns_capable",
and the latter to "__kstrtab_capable" and "__kstrtab_ns_capable".
Then, we have the duplicated "__kstrtab_ns_capable".
To ensure the uniqueness, rename "__kstrtab_ns_*" to "__kstrtabns_*".
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Currently, EXPORT_SYMBOL_NS(_GPL) constructs the kernel symbol as
follows:
__ksymtab_SYMBOL.NAMESPACE
The sym_extract_namespace() in modpost allocates memory for the part
SYMBOL.NAMESPACE when '.' is contained. One problem is that the pointer
returned by strdup() is lost because the symbol name will be copied to
malloc'ed memory by alloc_symbol(). No one will keep track of the
pointer of strdup'ed memory.
sym->namespace still points to the NAMESPACE part. So, you can free it
with complicated code like this:
free(sym->namespace - strlen(sym->name) - 1);
It complicates memory free.
To fix it elegantly, I swapped the order of the symbol and the
namespace as follows:
__ksymtab_NAMESPACE.SYMBOL
then, simplified sym_extract_namespace() so that it allocates memory
only for the NAMESPACE part.
I prefer this order because it is intuitive and also matches to major
languages. For example, NAMESPACE::NAME in C++, MODULE.NAME in Python.
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Pull modules updates from Jessica Yu:
"The main bulk of this pull request introduces a new exported symbol
namespaces feature. The number of exported symbols is increasingly
growing with each release (we're at about 31k exports as of 5.3-rc7)
and we currently have no way of visualizing how these symbols are
"clustered" or making sense of this huge export surface.
Namespacing exported symbols allows kernel developers to more
explicitly partition and categorize exported symbols, as well as more
easily limiting the availability of namespaced symbols to other parts
of the kernel. For starters, we have introduced the USB_STORAGE
namespace to demonstrate the API's usage. I have briefly summarized
the feature and its main motivations in the tag below.
Summary:
- Introduce exported symbol namespaces.
This new feature allows subsystem maintainers to partition and
categorize their exported symbols into explicit namespaces. Module
authors are now required to import the namespaces they need.
Some of the main motivations of this feature include: allowing
kernel developers to better manage the export surface, allow
subsystem maintainers to explicitly state that usage of some
exported symbols should only be limited to certain users (think:
inter-module or inter-driver symbols, debugging symbols, etc), as
well as more easily limiting the availability of namespaced symbols
to other parts of the kernel.
With the module import requirement, it is also easier to spot the
misuse of exported symbols during patch review.
Two new macros are introduced: EXPORT_SYMBOL_NS() and
EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in
Documentation/kbuild/namespaces.rst.
- Some small code and kbuild cleanups here and there"
* tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Remove leftover '#undef' from export header
module: remove unneeded casts in cmp_name()
module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES
module: remove redundant 'depends on MODULES'
module: Fix link failure due to invalid relocation on namespace offset
usb-storage: export symbols in USB_STORAGE namespace
usb-storage: remove single-use define for debugging
docs: Add documentation for Symbol Namespaces
scripts: Coccinelle script for namespace dependencies.
modpost: add support for generating namespace dependencies
export: allow definition default namespaces in Makefiles or sources
module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
modpost: add support for symbol namespaces
module: add support for symbol namespaces.
export: explicitly align struct kernel_symbol
module: support reading multiple values per modinfo tag
Arnd Bergmann reported false-positive modpost warnings detected by his
randconfig testing of linux-next.
Actually, this happens under the combination of CONFIG_MODVERSIONS
and CONFIG_TRIM_UNUSED_KSYMS since commit 15bfc2348d ("modpost:
check for static EXPORT_SYMBOL* functions").
For example, arch/arm/config/multi_v7_defconfig + CONFIG_MODVERSIONS
+ CONFIG_TRIM_UNUSED_KSYMS produces the following false-positives:
WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
WARNING: "ftrace_set_clr_event" [vmlinux] is a static (unknown)
WARNING: "__muldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
WARNING: "__ucmpdi2" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lmul" [vmlinux] is a static (unknown)
WARNING: "__bswapsi2" [vmlinux] is a static (unknown)
WARNING: "__bswapdi2" [vmlinux] is a static (unknown)
WARNING: "__ashldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsl" [vmlinux] is a static (unknown)
The root cause of the problem is not in the modpost, but in the
implementation of CONFIG_TRIM_UNUSED_KSYMS.
If there is at least one untrimmed symbol in the file, genksyms is
invoked to calculate CRC of *all* the exported symbols in that file
even if some of them have been trimmed due to no caller existing.
As a result, .tmp_*.ver files contain CRC of trimmed symbols, thus
unneeded, orphan __crc* symbols are added to objects. It had been
harmless until recently.
With commit 15bfc2348d ("modpost: check for static EXPORT_SYMBOL*
functions"), it is now harmful because the bogus __crc* symbols make
modpost call sym_update_crc() to add the symbols to the hash table,
but there is no one that clears the ->is_static member.
I gave Fixes to the first commit that uncovered the issue, but the
potential problem has long existed since commit f235541699
("export.h: allow for per-symbol configurable EXPORT_SYMBOL()").
Fixes: 15bfc2348d ("modpost: check for static EXPORT_SYMBOL* functions")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Commit 8651ec01da ("module: add support for symbol namespaces.")
broke linking for arm64 defconfig:
| lib/crypto/arc4.o: In function `__ksymtab_arc4_setkey':
| arc4.c:(___ksymtab+arc4_setkey+0x8): undefined reference to `no symbol'
| lib/crypto/arc4.o: In function `__ksymtab_arc4_crypt':
| arc4.c:(___ksymtab+arc4_crypt+0x8): undefined reference to `no symbol'
This is because the dummy initialisation of the 'namespace_offset' field
in 'struct kernel_symbol' when using EXPORT_SYMBOL on architectures with
support for PREL32 locations uses an offset from an absolute address (0)
in an effort to trick 'offset_to_pointer' into behaving as a NOP,
allowing non-namespaced symbols to be treated in the same way as those
belonging to a namespace.
Unfortunately, place-relative relocations require a symbol reference
rather than an absolute value and, although x86 appears to get away with
this due to placing the kernel text at the top of the address space, it
almost certainly results in a runtime failure if the kernel is relocated
dynamically as a result of KASLR.
Rework 'namespace_offset' so that a value of 0, which cannot occur for a
valid namespaced symbol, indicates that the corresponding symbol does
not belong to a namespace.
Cc: Matthias Maennich <maennich@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 8651ec01da ("module: add support for symbol namespaces.")
Reported-by: kbuild test robot <lkp@intel.com>
Tested-by: Matthias Maennich <maennich@google.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matthias Maennich <maennich@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The conditional, define(__KERNEL__), was added by commit f235541699
("export.h: allow for per-symbol configurable EXPORT_SYMBOL()").
It was needed at that time to avoid the build error of modpost
with CONFIG_TRIM_UNUSED_KSYMS=y.
Since commit b2c5cdcfd4 ("modpost: remove symbol prefix support"),
modpost no longer includes linux/export.h, thus the define(__KERNEL__)
is unneeded.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
To avoid excessive usage of EXPORT_SYMBOL_NS(sym, MY_NAMESPACE), where
MY_NAMESPACE will always be the namespace we are exporting to, allow
exporting all definitions of EXPORT_SYMBOL() and friends by defining
DEFAULT_SYMBOL_NAMESPACE.
For example, to export all symbols defined in usb-common into the
namespace USB_COMMON, add a line like this to drivers/usb/common/Makefile:
ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=USB_COMMON
That is equivalent to changing all EXPORT_SYMBOL(sym) definitions to
EXPORT_SYMBOL_NS(sym, USB_COMMON). Subsequently all symbol namespaces
functionality will apply.
Another way of making use of this feature is to define the namespace
within source or header files similar to how TRACE_SYSTEM defines are
used:
#undef DEFAULT_SYMBOL_NAMESPACE
#define DEFAULT_SYMBOL_NAMESPACE USB_COMMON
Please note that, as opposed to TRACE_SYSTEM, DEFAULT_SYMBOL_NAMESPACE
has to be defined before including include/linux/export.h.
If DEFAULT_SYMBOL_NAMESPACE is defined, a symbol can still be exported
to another namespace by using EXPORT_SYMBOL_NS() and friends with
explicitly specifying the namespace.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL() macros can be used to
export a symbol to a specific namespace. There are no _GPL_FUTURE and
_UNUSED variants because these are currently unused, and I'm not sure
they are necessary.
I didn't add EXPORT_SYMBOL_NS() for ASM exports; this patch sets the
namespace of ASM exports to NULL by default. In case of relative
references, it will be relocatable to NULL. If there's a need, this
should be pretty easy to add.
A module that wants to use a symbol exported to a namespace must add a
MODULE_IMPORT_NS() statement to their module code; otherwise, modpost
will complain when building the module, and the kernel module loader
will emit an error and fail when loading the module.
MODULE_IMPORT_NS() adds a modinfo tag 'import_ns' to the module. That
tag can be observed by the modinfo command, modpost and kernel/module.c
at the time of loading the module.
The ELF symbols are renamed to include the namespace with an asm label;
for example, symbol 'usb_stor_suspend' in namespace USB_STORAGE becomes
'usb_stor_suspend.USB_STORAGE'. This allows modpost to do namespace
checking, without having to go through all the effort of parsing ELF and
relocation records just to get to the struct kernel_symbols.
On x86_64 I saw no difference in binary size (compression), but at
runtime this will require a word of memory per export to hold the
namespace. An alternative could be to store namespaced symbols in their
own section and use a separate 'struct namespaced_kernel_symbol' for
that section, at the cost of making the module loader more complex.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
This change allows growing struct kernel_symbol without wasting bytes to
alignment. It also concretized the alignment of ksymtab entries if
relative references are used for ksymtab entries.
struct kernel_symbol was already implicitly being aligned to the word
size, except on x86_64 and m68k, where it is aligned to 16 and 2 bytes,
respectively.
As far as I can tell there is no requirement for aligning struct
kernel_symbol to 16 bytes on x86_64, but gcc aligns structs to their
size, and the linker aligns the custom __ksymtab sections to the largest
data type contained within, so setting KSYM_ALIGN to 16 was necessary to
stay consistent with the code generated for non-ASM EXPORT_SYMBOL(). Now
that non-ASM EXPORT_SYMBOL() explicitly aligns to word size (8),
KSYM_ALIGN is no longer necessary.
In case of relative references, the alignment has been changed
accordingly to not waste space when adding new struct members.
As for m68k, struct kernel_symbol is aligned to 2 bytes even though the
structure itself is 8 bytes; using a 4-byte alignment shouldn't hurt.
I manually verified the output of the __ksymtab sections didn't change
on x86, x86_64, arm, arm64 and m68k. As expected, the section contents
didn't change, and the ELF section alignment only changed on x86_64 and
m68k. Feedback from other archs more than welcome.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
My main motivation of this commit is to clean up scripts/Kbuild.include
and scripts/Makefile.build.
Currently, CONFIG_TRIM_UNUSED_KSYMS works with a tricky gimmick;
possibly exported symbols are detected by letting $(CPP) replace
EXPORT_SYMBOL* with a special string '=== __KSYM_*===', which is
post-processed by sed, and passed to fixdep. The extra preprocessing
is costly, and hacking cmd_and_fixdep is ugly.
I came up with a new way to find exported symbols; insert a dummy
symbol __ksym_marker_* to each potentially exported symbol. Those
dummy symbols are picked up by $(NM), post-processed by sed, then
appended to .*.cmd files. I collected the post-process part to a
new shell script scripts/gen_ksymdeps.sh for readability. The dummy
symbols are put into the .discard.* section so that the linker
script rips them off the final vmlinux or modules.
A nice side-effect is building with CONFIG_TRIM_UNUSED_KSYMS will
be much faster.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Pull more Kbuild updates from Masahiro Yamada:
- add build_{menu,n,g,x}config targets for compile-testing Kconfig
- fix and improve recursive dependency detection in Kconfig
- fix parallel building of menuconfig/nconfig
- fix syntax error in clang-version.sh
- suppress distracting log from syncconfig
- remove obsolete "rpm" target
- remove VMLINUX_SYMBOL(_STR) macro entirely
- fix microblaze build with CONFIG_DYNAMIC_FTRACE
- move compiler test for dead code/data elimination to Kconfig
- rename well-known LDFLAGS variable to KBUILD_LDFLAGS
- misc fixes and cleanups
* tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: rename LDFLAGS to KBUILD_LDFLAGS
kbuild: pass LDFLAGS to recordmcount.pl
kbuild: test dead code/data elimination support in Kconfig
initramfs: move gen_initramfs_list.sh from scripts/ to usr/
vmlinux.lds.h: remove stale <linux/export.h> include
export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR()
Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci
kbuild: make sorting initramfs contents independent of locale
kbuild: remove "rpm" target, which is alias of "rpm-pkg"
kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt
kconfig: suppress "configuration written to .config" for syncconfig
kconfig: fix "Can't open ..." in parallel build
kbuild: Add a space after `!` to prevent parsing as file pattern
scripts: modpost: check memory allocation results
kconfig: improve the recursive dependency report
kconfig: report recursive dependency involving 'imply'
kconfig: error out when seeing recursive dependency
kconfig: add build-only configurator targets
scripts/dtc: consolidate include path options in Makefile
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries,
each consisting of two 64-bit fields containing absolute references, to
the symbol itself and to a char array containing its name, respectively.
When we build the same configuration with KASLR enabled, we end up with an
additional ~192 KB of relocations in the .init section, i.e., one 24 byte
entry for each absolute reference, which all need to be processed at boot
time.
Given how the struct kernel_symbol that describes each entry is completely
local to module.c (except for the references emitted by EXPORT_SYMBOL()
itself), we can easily modify it to contain two 32-bit relative references
instead. This reduces the size of the __ksymtab section by 50% for all
64-bit architectures, and gets rid of the runtime relocations entirely for
architectures implementing KASLR, either via standard PIE linking (arm64)
or using custom host tools (x86).
Note that the binary search involving __ksymtab contents relies on each
section being sorted by symbol name. This is implemented based on the
input section names, not the names in the ksymtab entries, so this patch
does not interfere with that.
Given that the use of place-relative relocations requires support both in
the toolchain and in the module loader, we cannot enable this feature for
all architectures. So make it dependent on whether
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined.
Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the special case handling for Blackfin and Metag was removed by
commit 94e58e0ac3 ("export.h: remove code for prefixing symbols with
underscore"), VMLINUX_SYMBOL() is no-op.
Replace the remaining usages, then remove the definition of
VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a9760 ("arch: remove blackfin port"),
commit bb6fb6dfcc ("metag: Remove arch/metag/"), respectively.
No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
Clean up the export.h headers. I am keeping VMLINUX_SYMBOL() and
VMLINUX_SYMBOL_STR() because they are widely used.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
The previous patch introduced a separate inline asm version of the
krcrctab declaration template for use with 64-bit architectures, which
cannot refer to ELF symbols using 32-bit quantities.
This declaration should be equivalent to the C one for 32-bit
architectures, but just in case - unify them in a separate patch, which
can simply be dropped if it turns out to break anything.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.
This has a couple of downsides:
- Given that the CRCs are treated as memory addresses, we waste 4 bytes
for each CRC on 64 bit architectures,
- On architectures that support runtime relocation, a R_<arch>_RELATIVE
relocation entry is emitted for each CRC value, which identifies it
as a quantity that requires fixing up based on the actual runtime
load offset of the kernel. This results in corrupted CRCs unless we
explicitly undo the fixup (and this is currently being handled in the
core module code)
- Such runtime relocation entries take up 24 bytes of __init space
each, resulting in a x8 overhead in [uncompressed] kernel size for
CRCs.
Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset. Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant. Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.
So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff). To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.
Note that this mostly reverts commit d4703aefdb ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
Introduce LD_DEAD_CODE_DATA_ELIMINATION option for architectures to
select to build with -ffunction-sections, -fdata-sections, and link
with --gc-sections. It requires some work (documented) to ensure all
unreferenced entrypoints are live, and requires toolchain and build
verification, so it is made a per-arch option for now.
On a random powerpc64le build, this yelds a significant size saving,
it boots and runs fine, but there is a lot I haven't tested as yet, so
these savings may be reduced if there are bugs in the link.
text data bss dec filename
11169741 1180744 1923176 14273661 vmlinux
10445269 1004127 1919707 13369103 vmlinux.dce
~700K text, ~170K data, 6% removed from kernel image size.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Here the need is for a macro that checks whether the given symbol is
defined or not, which has nothing to do with config.
The new macro __is_defined() is a better fit for this case.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
Like with kconfig options, we now have the ability to compile in and
out individual EXPORT_SYMBOL() declarations based on the content of
include/generated/autoksyms.h. However we don't want the entire
world to be rebuilt whenever that file is touched.
Let's apply the same build dependency trick used for CONFIG_* symbols
where the time stamp of empty files whose paths matching those symbols
is used to trigger fine grained rebuilds. In our case the key is the
symbol name passed to EXPORT_SYMBOL().
However, unlike config options, we cannot just use fixdep to parse
the source code for EXPORT_SYMBOL(ksym) because several variants exist
and parsing them all in a separate tool, and keeping it in synch, is
not trivially maintainable. Furthermore, there are variants such as
EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
that are instanciated via a macro for which we can't easily determine
the actual exported symbol name(s) short of actually running the
preprocessor on them.
Storing the symbol name string in a special ELF section doesn't work
for targets that output assembly or preprocessed source.
So the best way is really to leverage the preprocessor by having it
output actual symbol names anchored by a special sequence that can be
easily filtered out. Then the list of symbols is simply fed to fixdep
to be merged with the other dependencies.
That implies the preprocessor is executed twice for each source file.
A previous attempt relied on a warning pragma for each EXPORT_SYMBOL()
instance that was filtered apart from stderr by the build system with
a sed script during the actual compilation pass. Unfortunately the
preprocessor/compiler diagnostic output isn't stable between versions
and this solution, although more efficient, was deemed too fragile.
Because of the lowercasing performed by fixdep, there might be name
collisions triggering spurious rebuilds for similar symbols. But this
shouldn't be a big issue in practice. (This is the case for CONFIG_*
symbols and I didn't want to be different here, whatever the original
reason for doing so.)
To avoid needless build overhead, the exported symbol name gathering is
performed only when CONFIG_TRIM_UNUSED_KSYMS is selected.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Similar to include/generated/autoconf.h, include/generated/autoksyms.h
will contain a list of defines for each EXPORT_SYMBOL() that we want
active. The format is:
#define __KSYM_<symbol_name> 1
This list will be auto-generated with another patch. For now we only
include the preprocessor magic to automatically create or omit the
corresponding struct kernel_symbol declaration.
Given the content of include/generated/autoksyms.h may not be known in
advance, an empty file is created early on to let the build proceed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
sparse complains about any __ksymtab symbols with the following:
warning: symbol '__ksymtab_...' was not declared. Should it be static?
due to Andi's patch making it non-static.
Mollify sparse by declaring the symbol extern, otherwise we get
drowned in sparse warnings for anything that uses EXPORT_SYMBOL
in the sources, making it easy to miss real warnings.
Fixes: e0f244c63f ("asmlinkage, module: Make ksymtab [...] __visible")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Make the ksymtab symbols for EXPORT_SYMBOL visible.
This prevents the LTO compiler from adding a .NUMBER prefix,
which avoids various problems in later export processing.
Cc: rusty@rustcorp.com.au
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_". But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.
Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something. So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
for pasting.
(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
4) Make everyone use them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Tested-by: James Hogan <james.hogan@imgtec.com> (metag)
A lot of files pull in module.h when all they are really
looking for is the basic EXPORT_SYMBOL functionality. The
recent data from Ingo[1] shows that this is one of several
instances that has a significant impact on compile times,
and it should be targeted for factoring out (as done here).
Note that several commonly used header files in include/*
directly include <linux/module.h> themselves (some 34 of them!)
The most commonly used ones of these will have to be made
independent of module.h before the full benefit of this change
can be realized.
We also transition THIS_MODULE from module.h to export.h,
since there are lots of files with subsystem structs that
in turn will have a struct module *owner and only be doing:
.owner = THIS_MODULE;
and absolutely nothing else modular. So, we also want to have
the THIS_MODULE definition present in the lightweight header.
[1] https://lkml.org/lkml/2011/5/23/76
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
