Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 19 January 2017 at 00:15, Linus Torvalds wrote: > On Wed, Jan 18, 2017 at 2:37 PM, Ard Biesheuvel > wrote: >> >> For a ballpark number of 10,000 CRCs in the core kernel, this would >> increase the size of the image by 40 KB for 32-bit

[PATCH] cxl: drop unused header asm/pnv-pci.h

The kernel API does not use anything from this header file. Signed-off-by: Greg Kurz --- drivers/misc/cxl/api.c |1 - 1 file changed, 1 deletion(-) diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 1b35e33d2434..bcc030eacab7 100644 ---

Re: [PATCH 2/2] of: Add function for generating a DT modalias with a newline

On Mon, Jan 16, 2017 at 02:41:22PM -0600, Rob Herring wrote: > The modalias sysfs attr is lacking a newline for DT aliases on platform > devices. The macio and ibmebus correctly add the newline, but open code it. > Introduce a new function, of_device_modalias(), that fills the buffer with > the

Re: [PATCH] cxl: drop unused header asm/pnv-pci.h

On 19/01/17 21:50, Greg Kurz wrote: The kernel API does not use anything from this header file. Signed-off-by: Greg Kurz Reviewed-by: Andrew Donnellan -- Andrew Donnellan OzLabs, ADL Canberra andrew.donnel...@au1.ibm.com IBM

[RFC PATCH v2] modversions: redefine kcrctab entries as relative CRC pointers

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: - On architectures that support runtime relocation, a R__RELATIVE

[PATCH v4 09/15] livepatch: remove unnecessary object loaded check

klp_patch_object()'s callers already ensure that the object is loaded, so its call to klp_is_object_loaded() is unnecessary. This will also make it possible to move the patching code into a separate file. Signed-off-by: Josh Poimboeuf Acked-by: Miroslav Benes

[PATCH 2/8] powerpc/nvram: Return directly after a failed kmalloc() in dev_nvram_write()

From: Markus Elfring Date: Thu, 19 Jan 2017 15:44:03 +0100 Return directly after a call of the function "kmalloc" failed here. Signed-off-by: Markus Elfring --- arch/powerpc/kernel/nvram_64.c | 4 +--- 1 file changed, 1

[PATCH] powerpc/rtas_flash: Move an assignment for the variable "rc" in manage_flash_write()

From: Markus Elfring Date: Thu, 19 Jan 2017 21:20:09 +0100 A local variable was set to an error code before a concrete error situation was detected. Thus move the corresponding assignment into an if branch to indicate a software failure there. This issue was

Re: [PATCH] powerpc/rtas_flash: Move an assignment for the variable "rc" in manage_flash_write()

On 01/19/2017 12:33 PM, SF Markus Elfring wrote: > From: Markus Elfring > Date: Thu, 19 Jan 2017 21:20:09 +0100 > > A local variable was set to an error code before a concrete error situation > was detected. Thus move the corresponding assignment into an if branch

Re: [PATCH 3/8] powerpc/nvram: Move an assignment for the variable "ret" in dev_nvram_write()

On 01/19/2017 08:56 AM, SF Markus Elfring wrote: > From: Markus Elfring > Date: Thu, 19 Jan 2017 15:55:36 +0100 > > A local variable was set to an error code before a concrete error situation > was detected. Thus move the corresponding assignment into an if branch

Re: [PATCH v4 2/5] ia64: reuse append_elf_note() and final_note() functions

Hari Bathini writes: > Get rid of multiple definitions of append_elf_note() & final_note() > functions. Reuse these functions compiled under CONFIG_CRASH_CORE > Also, define Elf_Word and use it instead of generic u32 or the more > specific Elf64_Word. > >

[PATCH v4 03/15] livepatch: create temporary klp_update_patch_state() stub

Create temporary stubs for klp_update_patch_state() so we can add TIF_PATCH_PENDING to different architectures in separate patches without breaking build bisectability. Signed-off-by: Josh Poimboeuf Reviewed-by: Petr Mladek --- include/linux/livepatch.h |

[PATCH v4 10/15] livepatch: move patching functions into patch.c

Move functions related to the actual patching of functions and objects into a new patch.c file. Signed-off-by: Josh Poimboeuf Acked-by: Miroslav Benes Reviewed-by: Petr Mladek Reviewed-by: Kamalesh Babulal ---

[PATCH 3/8] powerpc/nvram: Move an assignment for the variable "ret" in dev_nvram_write()

From: Markus Elfring Date: Thu, 19 Jan 2017 15:55:36 +0100 A local variable was set to an error code before a concrete error situation was detected. Thus move the corresponding assignment into an if branch to indicate a software failure there. This issue was

[PATCH 7/8] powerpc/nvram: Improve size determinations in three functions

From: Markus Elfring Date: Thu, 19 Jan 2017 17:15:30 +0100 Replace the specification of data structures by references for local variables as the parameter for the operator "sizeof" to make the corresponding size determination a bit safer. Signed-off-by: Markus

[PATCH v4 01/15] stacktrace/x86: add function for detecting reliable stack traces

For live patching and possibly other use cases, a stack trace is only useful if it can be assured that it's completely reliable. Add a new save_stack_trace_tsk_reliable() function to achieve that. Note that if the target task isn't the current task, and the target task is allowed to run, then it

[PATCH v4 07/15] livepatch/s390: add TIF_PATCH_PENDING thread flag

From: Miroslav Benes Update a task's patch state when returning from a system call or user space interrupt, or after handling a signal. This greatly increases the chances of a patch operation succeeding. If a task is I/O bound, it can be patched when returning from a system

[PATCH 6/8] powerpc/nvram: Delete three error messages for a failed memory allocation

From: Markus Elfring Date: Thu, 19 Jan 2017 16:56:46 +0100 The script "checkpatch.pl" pointed information out like the following. WARNING: Possible unnecessary 'out of memory' message Thus fix affected source code places. Signed-off-by: Markus Elfring

[PATCH 8/8] powerpc/nvram: Move an assignment for the variable "err" in nvram_scan_partitions()

From: Markus Elfring Date: Thu, 19 Jan 2017 17:27:37 +0100 A local variable was set to an error code before a concrete error situation was detected. Thus move the corresponding assignment into an if branch to indicate a software failure there. Signed-off-by:

[PATCH v4 05/15] livepatch/powerpc: add TIF_PATCH_PENDING thread flag

Add the TIF_PATCH_PENDING thread flag to enable the new livepatch per-task consistency model for powerpc. The bit getting set indicates the thread has a pending patch which needs to be applied when the thread exits the kernel. The bit is included in the _TIF_USER_WORK_MASK macro so that

Re: [RFC PATCH v2] modversions: redefine kcrctab entries as relative CRC pointers

On 19 January 2017 at 16:55, Ard Biesheuvel wrote: > On 19 January 2017 at 12:02, Ard Biesheuvel wrote: >> The modversion symbol CRCs are emitted as ELF symbols, which allows us to >> easily populate the kcrctab sections by relying on the

[PATCH 4/8] powerpc/nvram: Return directly after a failed parameter validation in dev_nvram_read()

From: Markus Elfring Date: Thu, 19 Jan 2017 16:12:48 +0100 * Return directly after an inappropriate input parameter was detected. * Delete an initialisation for the variable "tmp" at the beginning which became unnecessary with this refactoring. Signed-off-by:

[PATCH 5/8] powerpc/nvram: Return directly after a failed kmalloc() in dev_nvram_read()

From: Markus Elfring Date: Thu, 19 Jan 2017 16:50:31 +0100 Return directly after a call of the function "kmalloc" failed here. Signed-off-by: Markus Elfring --- arch/powerpc/kernel/nvram_64.c | 6 ++ 1 file changed, 2

[PATCH v4 02/15] x86/entry: define _TIF_ALLWORK_MASK flags explicitly

The _TIF_ALLWORK_MASK macro automatically includes the least-significant 16 bits of the thread_info flags, which is less than obvious and tends to create confusion and surprises when reading or modifying the code. Define the flags explicitly. Signed-off-by: Josh Poimboeuf

[PATCH v4 08/15] livepatch: separate enabled and patched states

Once we have a consistency model, patches and their objects will be enabled and disabled at different times. For example, when a patch is disabled, its loaded objects' funcs can remain registered with ftrace indefinitely until the unpatching operation is complete and they're no longer in use.

[PATCH 0/8] PowerPC-NVRAM: Fine-tuning for some function implementations

From: Markus Elfring Date: Thu, 19 Jan 2017 17:41:23 +0100 Some update suggestions were taken into account from static source code analysis. Markus Elfring (8): Return directly after a failed parameter validation in dev_nvram_write() Return directly after a

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Thu, Jan 19, 2017 at 1:22 AM, Ard Biesheuvel wrote: >> >> Your genksyms.c change is not exactly obvious. I looked at it, and my >> brain just shut down. Why both the >> >> LONG(0x%08lx); >> >> _and_ the >> >> "%s__crc_%s = 0x%08lx;\n" >> >> in the linker script?

[PATCH v4 04/15] livepatch/x86: add TIF_PATCH_PENDING thread flag

Add the TIF_PATCH_PENDING thread flag to enable the new livepatch per-task consistency model for x86_64. The bit getting set indicates the thread has a pending patch which needs to be applied when the thread exits the kernel. The bit is placed in the _TIF_ALLWORK_MASK macro, which results in

[PATCH v4 13/15] livepatch: change to a per-task consistency model

Change livepatch to use a basic per-task consistency model. This is the foundation which will eventually enable us to patch those ~10% of security patches which change function or data semantics. This is the biggest remaining piece needed to make livepatch more generally useful. This code stems

[PATCH v4 14/15] livepatch: add /proc//patch_state

Expose the per-task patch state value so users can determine which tasks are holding up completion of a patching operation. Signed-off-by: Josh Poimboeuf Reviewed-by: Petr Mladek Reviewed-by: Miroslav Benes ---

Re: [RFC PATCH v2] modversions: redefine kcrctab entries as relative CRC pointers

On 19 January 2017 at 12:02, Ard Biesheuvel wrote: > 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

RE: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

From: Ard Biesheuvel > Sent: 18 January 2017 13:53 .. > It turns out that this odd treatment of absolute symbols (i.e., > symbols having section number SHN_ABS) is a known issue in GNU ld > > https://sourceware.org/ml/binutils/2012-05/msg00019.html ... Jeepers - that is truly f*cked. I've even

[PATCH v4 11/15] livepatch: use kstrtobool() in enabled_store()

The sysfs enabled value is a boolean, so kstrtobool() is a better fit for parsing the input string since it does the range checking for us. Suggested-by: Petr Mladek Signed-off-by: Josh Poimboeuf Acked-by: Miroslav Benes Reviewed-by: Petr

[PATCH v4 06/15] livepatch/s390: reorganize TIF thread flag bits

From: Jiri Slaby Group the TIF thread flag bits by their inclusion in the _TIF_WORK and _TIF_TRACE macros. Signed-off-by: Jiri Slaby Signed-off-by: Josh Poimboeuf Reviewed-by: Miroslav Benes ---

[PATCH v4 15/15] livepatch: allow removal of a disabled patch

From: Miroslav Benes Currently we do not allow patch module to unload since there is no method to determine if a task is still running in the patched code. The consistency model gives us the way because when the unpatching finishes we know that all tasks were marked as safe to

[PATCH v4 00/15] livepatch: hybrid consistency model

Here's v4, based on linux-next/master. Mostly minor changes this time, primarily due to Petr's v3 comments. v4: - add warnings for "impossible" scenarios in __save_stack_trace_reliable() - sort _TIF_ALLWORK_MASK flags - move klp_transition_work to transition.c. This resulted in the following

[PATCH v4 12/15] livepatch: store function sizes

For the consistency model we'll need to know the sizes of the old and new functions to determine if they're on the stacks of any tasks. Signed-off-by: Josh Poimboeuf Acked-by: Miroslav Benes Reviewed-by: Petr Mladek Reviewed-by: Kamalesh

[PATCH 1/8] powerpc/nvram: Return directly after a failed parameter validation in dev_nvram_write()

From: Markus Elfring Date: Thu, 19 Jan 2017 15:22:56 +0100 * Return directly after an inappropriate input parameter was detected. * Delete an initialisation for the variable "tmp" at the beginning and an assignment for the variable "ret" which became unnecessary

[PATCH v8 1/3] PCI: Ignore requested alignment for IOV BARs

We would call pci_reassigndev_resource_alignment() before pci_init_capabilities(). So the requested alignment would never work for IOV BARs. Furthermore, it's meaningless to request additional alignment for IOV BARs, the IOV BAR alignment is only determined by the VF BAR size. Signed-off-by:

[PATCH v8 2/3] PCI: Make sure the driver could get correct BAR size from pci_resource_len()

When using resource_alignment kernel parameter, the current implement reassigns the alignment by expanding resources' size. So there exists two kinds of *size* for one PCI BAR. One is the hardware size, the other is the allocated size. Currently pci_resource_len() used by drivers return the

[PATCH v8 0/3] PCI: Introduce a way to enforce all MMIO BARs not to share PAGE_SIZE

This series introduces a way for PCI resource allocator to force MMIO BARs not to share PAGE_SIZE. This would make sense to VFIO driver. Because current VFIO implementation disallows to mmap sub-page(size < PAGE_SIZE) MMIO BARs which may share the same page with other BARs for security reasons.

Re: powerpc/nvram: Move an assignment for the variable "ret" in dev_nvram_write()

> I think you really could have squashed patches 1-3 into a single patch > that returns directly after any failure. Thanks for your constructive feedback. I have got software development concerns around such patch squashing. > At this point you might as well remove that label and move the

[PATCH v8 3/3] PCI: Add a macro to set default alignment for all PCI devices

When vfio passthroughs a PCI device of which MMIO BARs are smaller than PAGE_SIZE, guest will not handle the mmio accesses to the BARs which leads to mmio emulations in host. This is because vfio will not allow to passthrough one BAR's mmio page which may be shared with other BARs. Otherwise,