- 15 Apr, 2019 11 commits
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Kishon Vijay Abraham I authored
of_pci_get_max_link_speed() is built only if CONFIG_PCI is enabled. Make of_pci_get_max_link_speed() to be also used by PCI Endpoint controllers with just CONFIG_PCI_ENDPOINT enabled. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
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Kishon Vijay Abraham I authored
SERDES connected to the PCIe controller in AM654 requires power on reset enable (POR_EN) to be set in the SERDES. The SERDES driver sets POR_EN in the reset ops and it has to be invoked before init or enable ops. In order for SERDES driver to set POR_EN, invoke the phy_reset() API in pci-keystone driver. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Add PCIe RC support for AM654x Platforms in pci-keystone.c Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Add devicetree binding documentation for PCIe in RC mode present in AM654 SoC. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Rob Herring <robh@kernel.org>
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Kishon Vijay Abraham I authored
hook_fault_code() is an ARM32 specific API for hooking into data abort. AM65X platforms (that integrate ARM v8 cores and select CONFIG_ARM64 as arch) rely on pci-keystone.c but on them the enumeration of a non-present BDF does not trigger a bus error, so the fixup exception provided by calling hook_fault_code() is not needed and can be guarded with CONFIG_ARM. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> [lorenzo.pieralisi@arm.com: commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Synopsys designware version >= 4.80 uses a separate register space for programming ATU. The current code identifies if there exists a separate register space by accessing the register address of ATUs in designware version < 4.80. Accessing this address results in abort in the case of K2G. Fix it here by adding "version" member to struct dw_pcie. This should be set by platform specific drivers and designware core will use it to identify if the platform has a separate ATU space. For platforms which have not populated the version member, the old method of identification will still be used. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
iatu_unroll_enabled flag is set only for Designware in host mode. However iATU unroll can be applicable for endpoint mode too. Set iatu_unroll_enabled flag in dw_pcie_setup() which is common for both host mode and endpoint mode. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Document "atu" reg-names required to get the register space for ATU in Synopsys designware core version >= 4.80. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Explicitly set the PCIe mode to BOOTCFG_DEVCFG instead of always relying on the default values. This is required when EP mode has to be explicitly written to BOOTCFG_DEVCFG register. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Add "ti,syscon-pcie-mode" dt-binding to hold phandle to the syscon register that should be used to configure PCIe in RC mode or EP mode. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Rob Herring <robh@kernel.org>
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Kishon Vijay Abraham I authored
Move platform_get_resource() calls for resources that are applicable to both host and endpoint mode (ie "dbics" and "app") from ks_add_pcie_port() to the probe() callback, in preparation for adding endpoint support to pci-keystone driver. No functional change intended. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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- 11 Apr, 2019 5 commits
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Kishon Vijay Abraham I authored
Use platform_get_resource_byname() instead of platform_get_resource() which uses an index to get memory resources. While at that get the memory resource defined specifically for configuration space instead of deriving the configuration space address from dbics address space. Since the pci-keystone driver has never worked in the mainline kernel, DT backward compatibility is not an issue. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
No functional change. Instead of having two functions ks_pcie_add_pcie_port() and ks_pcie_dw_host_init() for initializing host, have a single function to perform all the host initialization. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Add "reg-names" binding information in order for device tree node to be populated with the correct register strings. This will break old DT compatibility. However Keystone PCI has never worked in upstream kernel due to lack of SERDES support, so, before SERDES support is added, cleanup the Keystone PCI dt-bindings. This new binding will also be used by PCI in AM654 platform. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Rob Herring <robh@kernel.org>
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Kishon Vijay Abraham I authored
pci-keystone driver uses irq_of_parse_and_map() to get irq number of error_irq. Use platform_get_irq() instead and move platform_get_irq() and request_irq() of error_irq from ks_pcie_add_pcie_port to ks_pcie_probe since error_irq is common to both RC mode and EP mode. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Add start_link()/stop_link() dw_pcie_ops and invoke ks_pcie_start_link() directly from host_init. start_link()/stop_link() ops are required for adding EP mode support. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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- 04 Apr, 2019 8 commits
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Kishon Vijay Abraham I authored
Platforms which populate msi_host_init() have their own MSI controller logic. Writing to MSI control registers on platforms which do not use Designware's MSI controller logic might have side effects. To be safe, do not write to MSI control registers if the platform uses its own MSI controller logic instead of Designware's MSI one. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Now that Keystone started using its own msi_irq_chip, remove Keystone specific callback functions defined in dw_pcie_host_ops. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Use Keystone specific msi_irq_chip to configure the MSI controller logic in the PCIe keystone wrapper instead of using the default Designware msi_irq chip (dw_pci_msi_bottom_irq_chip) with callback functions for configuring the Keystone MSI controller. This will help to remove Keystone specific callback functions added in dw_pcie_host_ops. Move the default msi_irq_chip assignment to dw_pcie_host_init since platforms that doesn't use the default msi_irq_chip will assign msi_irq_chip in the msi_host_init() callback. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
Platforms using DesignWare IP use dw_pci_msi_bottom_irq_chip for configuring the MSI controller logic within the DesignWare IP. However certain platforms like Keystone (K2G) which uses DesignWare IP have their own MSI controller logic. For handling such platforms, the irqchip ops use msi_irq_ack(), msi_set_irq(), msi_clear_irq() callback functions. Add support to use different msi_irq_chip with default set to dw_pci_msi_bottom_irq_chip. This is in preparation to get rid of msi_irq_ack(), msi_set_irq(), msi_clear_irq() and other Keystone specific dw_pcie_host_ops. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
ks_pcie_msi_irq_handler() invokes ks_pcie_handle_msi_irq() for handling the interrupts. Having two functions for handling the interrupt was used when keystone PCIe driver was implemented using two files but with commit b492aca3 ("PCI: keystone: Merge pci-keystone-dw.c and pci-keystone.c"), which merged the keystone PCIe driver to use a single file, two functions for handling the interrupt handler are not required. Handle MSI interrupt in a single interrupt handler here. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
ks_pcie_msi_irq_handler() uses 'virq' to get the IRQ number offset. This offset is used to get the correct MSI_IRQ_STATUS register corresponding to the IRQ line that raised the interrupt. There is no guarantee that 'virq' assigned for consecutive hardware IRQ will be contiguous and this might get us an incorrect IRQ number offset. Fix it here by using 'hwirq' to get the IRQ number offset. Since we don't store the 'virq' numbers of all the IRQ numbers, stop checking if irq count is greater than MAX_MSI_HOST_IRQS and remove MAX_MSI_HOST_IRQS. Link: https://lkml.kernel.org/r/bb081d21-7c03-0357-4294-7e92d95d838c@arm.comSigned-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
ks_pcie_get_irq_controller_info() is used to configure both MSI and legacy interrupt. This will prevent MSI or legacy interrupt specific intializations. Add separate functions to configure MSI and legacy interrupts. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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Kishon Vijay Abraham I authored
No functional change. Change both MSI interrupt and legacy interrupt related macros to take an additional argument in order to return the correct register offset. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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- 17 Mar, 2019 14 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds authored
Pull more Kbuild updates from Masahiro Yamada: - add more Build-Depends to Debian source package - prefix header search paths with $(srctree)/ - make modpost show verbose section mismatch warnings - avoid hard-coded CROSS_COMPILE for h8300 - fix regression for Debian make-kpkg command - add semantic patch to detect missing put_device() - fix some warnings of 'make deb-pkg' - optimize NOSTDINC_FLAGS evaluation - add warnings about redundant generic-y - clean up Makefiles and scripts * tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove stale lxdialog/.gitignore kbuild: force all architectures except um to include mandatory-y kbuild: warn redundant generic-y Revert "modsign: Abort modules_install when signing fails" kbuild: Make NOSTDINC_FLAGS a simply expanded variable kbuild: deb-pkg: avoid implicit effects coccinelle: semantic code search for missing put_device() kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb kbuild: deb-pkg: add CONFIG_ prefix to kernel config options kbuild: add workaround for Debian make-kpkg kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG} unicore32: simplify linker script generation for decompressor h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux- kbuild: move archive command to scripts/Makefile.lib modpost: always show verbose warning for section mismatch ia64: prefix header search path with $(srctree)/ libfdt: prefix header search paths with $(srctree)/ deb-pkg: generate correct build dependencies
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 asm updates from Thomas Gleixner: "Two cleanup patches removing dead conditionals and unused code" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Remove unused __constant_c_x_memset() macro and inlines x86/asm: Remove dead __GNUC__ conditionals
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Thomas Gleixner: "Three fixes for the fallout from the TSX errata workaround: - Prevent memory corruption caused by a unchecked out of bound array index. - Two trivial fixes to address compiler warnings" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Make dev_attr_allow_tsx_force_abort static perf/x86: Fixup typo in stub functions perf/x86/intel: Fix memory corruption
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds authored
Pull xen fix from Juergen Gross: "A fix for a Xen bug introduced by David's series for excluding ballooned pages in vmcores" * tag 'for-linus-5.1b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/balloon: Fix mapping PG_offline pages to user space
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git://github.com/martinetd/linuxLinus Torvalds authored
Pull 9p updates from Dominique Martinet: "Here is a 9p update for 5.1; there honestly hasn't been much. Two fixes (leak on invalid mount argument and possible deadlock on i_size update on 32bit smp) and a fall-through warning cleanup" * tag '9p-for-5.1' of git://github.com/martinetd/linux: 9p/net: fix memory leak in p9_client_create 9p: use inode->i_lock to protect i_size_write() under 32-bit 9p: mark expected switch fall-through
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kbuild test robot authored
Fixes: 400816f6 ("perf/x86/intel: Implement support for TSX Force Abort") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: kbuild-all@01.org Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190313184243.GA10820@lkp-sb-ep06
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Masahiro Yamada authored
When this .gitignore was added, lxdialog was an independent hostprogs-y. Now that all objects in lxdialog/ are directly linked to mconf, the lxdialog is no longer generated. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Masahiro Yamada authored
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Masahiro Yamada authored
The generic-y is redundant under the following condition: - arch has its own implementation - the same header is added to generated-y - the same header is added to mandatory-y If a redundant generic-y is found, the warning like follows is displayed: scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h I fixed up arch Kbuild files found by this. Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Douglas Anderson authored
This reverts commit caf6fe91. The commit was fine but is no longer needed as of commit 3a2429e1 ("kbuild: change if_changed_rule for multi-line recipe"). Let's go back to using ";" to be consistent. For some discussion, see: https://lkml.kernel.org/r/CAK7LNASde0Q9S5GKeQiWhArfER4S4wL1=R_FW8q0++_X3T5=hQ@mail.gmail.comSigned-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Douglas Anderson authored
During a simple no-op (nothing changed) build I saw 39 invocations of the C compiler with the argument "-print-file-name=include". We don't need to call the C compiler 39 times for this--one time will suffice. Let's change NOSTDINC_FLAGS to a simply expanded variable to avoid this since there doesn't appear to be any reason it should be recursively expanded. On my build this shaved ~400 ms off my "no-op" build. Note that the recursive expansion seems to date back to the (really old) commit e8f5bdb0 ("[PATCH] Makefile include path ordering"). It's a little unclear to me if the point of that patch was to switch the variable to be recursively expanded (which it did) or to avoid directly assigning to NOSTDINC_FLAGS (AKA to switch to +=) because someone else (out of tree?) was setting it. I presume later since if the only goal was to switch to recursive expansion the patch would have just removed the ":". Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Arseny Maslennikov authored
* The man page for dpkg-source(1) notes: > -b, --build directory [format-specific-parameters] > Build a source package (--build since dpkg 1.17.14). > <...> > > dpkg-source will build the source package with the first > format found in this ordered list: the format indicated > with the --format command line option, the format > indicated in debian/source/format, “1.0”. The fallback > to “1.0” is deprecated and will be removed at some point > in the future, you should always document the desired > source format in debian/source/format. See section > SOURCE PACKAGE FORMATS for an extensive description of > the various source package formats. Thus it would be more foolproof to explicitly use 1.0 (as we always did) than to rely on dpkg-source's defaults. * In a similar vein, debian/rules is not made executable by mkdebian, and dpkg-source warns about that but still silently fixes the file. Let's be explicit once again. Signed-off-by: Arseny Maslennikov <ar@cs.msu.ru> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Wen Yang authored
The of_find_device_by_node() takes a reference to the underlying device structure, we should release that reference. The implementation of this semantic code search is: In a function, for a local variable returned by calling of_find_device_by_node(), a, if it is released by a function such as put_device()/of_dev_put()/platform_device_put() after the last use, it is considered that there is no reference leak; b, if it is passed back to the caller via dev_get_drvdata()/platform_get_drvdata()/get_device(), etc., the reference will be released in other functions, and the current function also considers that there is no reference leak; c, for the rest of the situation, the current function should release the reference by calling put_device, this code search will report the corresponding error message. By using this semantic code search, we have found some object reference leaks, such as: commit 11907e9d ("ASoC: fsl-asoc-card: fix object reference leaks in fsl_asoc_card_probe") commit a12085d1 ("mtd: rawnand: atmel: fix possible object reference leak") commit 11493f26 ("mtd: rawnand: jz4780: fix possible object reference leak") There are still dozens of reference leaks in the current kernel code. Further, for the case of b, the object returned to other functions may also have a reference leak, we will continue to develop other cocci scripts to further check the reference leak. Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Julia Lawall <Julia.Lawall@lip6.fr> Reviewed-by: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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- 16 Mar, 2019 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linuxLinus Torvalds authored
Pull pidfd system call from Christian Brauner: "This introduces the ability to use file descriptors from /proc/<pid>/ as stable handles on struct pid. Even if a pid is recycled the handle will not change. For a start these fds can be used to send signals to the processes they refer to. With the ability to use /proc/<pid> fds as stable handles on struct pid we can fix a long-standing issue where after a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. With this patchset we enable a variety of use cases. One obvious example is that we can now safely delegate an important part of process management - sending signals - to processes other than the parent of a given process by sending file descriptors around via scm rights and not fearing that the given process will have been recycled in the meantime. It also allows for easy testing whether a given process is still alive or not by sending signal 0 to a pidfd which is quite handy. There has been some interest in this feature e.g. from systems management (systemd, glibc) and container managers. I have requested and gotten comments from glibc to make sure that this syscall is suitable for their needs as well. In the future I expect it to take on most other pid-based signal syscalls. But such features are left for the future once they are needed. This has been sitting in linux-next for quite a while and has not caused any issues. It comes with selftests which verify basic functionality and also test that a recycled pid cannot be signaled via a pidfd. Jon has written about a prior version of this patchset. It should cover the basic functionality since not a lot has changed since then: https://lwn.net/Articles/773459/ The commit message for the syscall itself is extensively documenting the syscall, including it's functionality and extensibility" * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add tests for pidfd_send_signal() signal: add pidfd_send_signal() syscall
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git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds authored
Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida
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