BMC/Intel-BMC/linux.git/arch/x86, branch dev-5.4

x86/i8259: Use printk_deferred() to prevent deadlock

2020-08-05T07:59:52+00:00

commit bdd65589593edd79b6a12ce86b3b7a7c6dae5208 upstream. 0day reported a possible circular locking dependency: Chain exists of: &irq_desc_lock_class --> console_owner --> &port_lock_key Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(&irq_desc_lock_class); The reason for this is a printk() in the i8259 interrupt chip driver which is invoked with the irq descriptor lock held, which reverses the lock operations vs. printk() from arbitrary contexts. Switch the printk() to printk_deferred() to avoid that. Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

KVM: LAPIC: Prevent setting the tscdeadline timer if the lapic is hw disabled

2020-08-05T07:59:52+00:00

commit d2286ba7d574ba3103a421a2f9ec17cb5b0d87a1 upstream. Prevent setting the tscdeadline timer if the lapic is hw disabled. Fixes: bce87cce88 (KVM: x86: consolidate different ways to test for in-kernel LAPIC) Cc: Signed-off-by: Wanpeng Li Message-Id: <1596165141-28874-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86/stacktrace: Fix reliable check for empty user task stacks

2020-08-05T07:59:51+00:00

[ Upstream commit 039a7a30ec102ec866d382a66f87f6f7654f8140 ] If a user task's stack is empty, or if it only has user regs, ORC reports it as a reliable empty stack. But arch_stack_walk_reliable() incorrectly treats it as unreliable. That happens because the only success path for user tasks is inside the loop, which only iterates on non-empty stacks. Generally, a user task must end in a user regs frame, but an empty stack is an exception to that rule. Thanks to commit 71c95825289f ("x86/unwind/orc: Fix error handling in __unwind_start()"), unwind_start() now sets state->error appropriately. So now for both ORC and FP unwinders, unwind_done() and !unwind_error() always means the end of the stack was successfully reached. So the success path for kthreads is no longer needed -- it can also be used for empty user tasks. Reported-by: Wang ShaoBo Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Tested-by: Wang ShaoBo Link: https://lkml.kernel.org/r/f136a4e5f019219cbc4f4da33b30c2f44fa65b84.1594994374.git.jpoimboe@redhat.com Signed-off-by: Sasha Levin

x86/unwind/orc: Fix ORC for newly forked tasks

2020-08-05T07:59:51+00:00

[ Upstream commit 372a8eaa05998cd45b3417d0e0ffd3a70978211a ] The ORC unwinder fails to unwind newly forked tasks which haven't yet run on the CPU. It correctly reads the 'ret_from_fork' instruction pointer from the stack, but it incorrectly interprets that value as a call stack address rather than a "signal" one, so the address gets incorrectly decremented in the call to orc_find(), resulting in bad ORC data. Fix it by forcing 'ret_from_fork' frames to be signal frames. Reported-by: Wang ShaoBo Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Tested-by: Wang ShaoBo Link: https://lkml.kernel.org/r/f91a8778dde8aae7f71884b5df2b16d552040441.1594994374.git.jpoimboe@redhat.com Signed-off-by: Sasha Levin

x86, vmlinux.lds: Page-align end of ..page_aligned sections

2020-07-29T08:18:45+00:00

commit de2b41be8fcccb2f5b6c480d35df590476344201 upstream. On x86-32 the idt_table with 256 entries needs only 2048 bytes. It is page-aligned, but the end of the .bss..page_aligned section is not guaranteed to be page-aligned. As a result, objects from other .bss sections may end up on the same 4k page as the idt_table, and will accidentially get mapped read-only during boot, causing unexpected page-faults when the kernel writes to them. This could be worked around by making the objects in the page aligned sections page sized, but that's wrong. Explicit sections which store only page aligned objects have an implicit guarantee that the object is alone in the page in which it is placed. That works for all objects except the last one. That's inconsistent. Enforcing page sized objects for these sections would wreckage memory sanitizers, because the object becomes artificially larger than it should be and out of bound access becomes legit. Align the end of the .bss..page_aligned and .data..page_aligned section on page-size so all objects places in these sections are guaranteed to have their own page. [ tglx: Amended changelog ] Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200721093448.10417-1-joro@8bytes.org Signed-off-by: Greg Kroah-Hartman

x86: math-emu: Fix up 'cmp' insn for clang ias

2020-07-29T08:18:40+00:00

[ Upstream commit 81e96851ea32deb2c921c870eecabf335f598aeb ] The clang integrated assembler requires the 'cmp' instruction to have a length prefix here: arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl') cmp $0xffffffff,-24(%ebp) ^ Make this a 32-bit comparison, which it was clearly meant to be. Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Reviewed-by: Nick Desaulniers Link: https://lkml.kernel.org/r/20200527135352.1198078-1-arnd@arndb.de Signed-off-by: Sasha Levin

irqdomain/treewide: Keep firmware node unconditionally allocated

2020-07-29T08:18:28+00:00

[ Upstream commit e3beca48a45b5e0e6e6a4e0124276b8248dcc9bb ] Quite some non OF/ACPI users of irqdomains allocate firmware nodes of type IRQCHIP_FWNODE_NAMED or IRQCHIP_FWNODE_NAMED_ID and free them right after creating the irqdomain. The only purpose of these FW nodes is to convey name information. When this was introduced the core code did not store the pointer to the node in the irqdomain. A recent change stored the firmware node pointer in irqdomain for other reasons and missed to notice that the usage sites which do the alloc_fwnode/create_domain/free_fwnode sequence are broken by this. Storing a dangling pointer is dangerous itself, but in case that the domain is destroyed later on this leads to a double free. Remove the freeing of the firmware node after creating the irqdomain from all affected call sites to cure this. Fixes: 711419e504eb ("irqdomain: Add the missing assignment of domain->fwnode for named fwnode") Reported-by: Andy Shevchenko Signed-off-by: Thomas Gleixner Acked-by: Bjorn Helgaas Acked-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/873661qakd.fsf@nanos.tec.linutronix.de Signed-off-by: Sasha Levin

genirq/affinity: Handle affinity setting on inactive interrupts correctly

2020-07-22T07:33:16+00:00

commit baedb87d1b53532f81b4bd0387f83b05d4f7eb9a upstream. Setting interrupt affinity on inactive interrupts is inconsistent when hierarchical irq domains are enabled. The core code should just store the affinity and not call into the irq chip driver for inactive interrupts because the chip drivers may not be in a state to handle such requests. X86 has a hacky workaround for that but all other irq chips have not which causes problems e.g. on GIC V3 ITS. Instead of adding more ugly hacks all over the place, solve the problem in the core code. If the affinity is set on an inactive interrupt then: - Store it in the irq descriptors affinity mask - Update the effective affinity to reflect that so user space has a consistent view - Don't call into the irq chip driver This is the core equivalent of the X86 workaround and works correctly because the affinity setting is established in the irq chip when the interrupt is activated later on. Note, that this is only effective when hierarchical irq domains are enabled by the architecture. Doing it unconditionally would break legacy irq chip implementations. For hierarchial irq domains this works correctly as none of the drivers can have a dependency on affinity setting in inactive state by design. Remove the X86 workaround as it is not longer required. Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts") Reported-by: Ali Saidi Signed-off-by: Thomas Gleixner Tested-by: Ali Saidi Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

copy_xstate_to_kernel: Fix typo which caused GDB regression

2020-07-22T07:33:04+00:00

commit 5714ee50bb4375bd586858ad800b1d9772847452 upstream. This fixes a regression encountered while running the gdb.base/corefile.exp test in GDB's test suite. In my testing, the typo prevented the sw_reserved field of struct fxregs_state from being output to the kernel XSAVES area. Thus the correct mask corresponding to XCR0 was not present in the core file for GDB to interrogate, resulting in the following behavior: [kev@f32-1 gdb]$ ./gdb -q testsuite/outputs/gdb.base/corefile/corefile testsuite/outputs/gdb.base/corefile/corefile.core Reading symbols from testsuite/outputs/gdb.base/corefile/corefile... [New LWP 232880] warning: Unexpected size of section `.reg-xstate/232880' in core file. With the typo fixed, the test works again as expected. Signed-off-by: Kevin Buettner Fixes: 9e4636545933 ("copy_xstate_to_kernel(): don't leave parts of destination uninitialized") Cc: Al Viro Cc: Dave Airlie Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

scsi: sr: remove references to BLK_DEV_SR_VENDOR, leave it enabled

2020-07-22T07:32:57+00:00

[ Upstream commit 679b2ec8e060ca7a90441aff5e7d384720a41b76 ] This kernel configuration is basically enabling/disabling sr driver quirks detection. While these quirks are for fairly rare devices (very old CD burners, and a glucometer), the additional detection of these models is a very minimal amount of code. The logic behind the quirks is always built into the sr driver. This also removes the config from all the defconfig files that are enabling this already. Link: https://lore.kernel.org/r/20200223191144.726-1-flameeyes@flameeyes.com Reviewed-by: Jens Axboe Signed-off-by: Diego Elio Pettenò Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin