BMC/Intel-BMC/linux.git/arch/powerpc/kernel/irq.c, branch dev-5.2

powerpc/irq: Don't WARN continuously in arch_local_irq_restore()

2019-07-31T05:24:51+00:00

[ Upstream commit 0fc12c022ad25532b66bf6f6c818ee1c1d63e702 ] When CONFIG_PPC_IRQ_SOFT_MASK_DEBUG is enabled (uncommon), we have a series of WARN_ON's in arch_local_irq_restore(). These are "should never happen" conditions, but if they do happen they can flood the console and render the system unusable. So switch them to WARN_ON_ONCE(). Fixes: e2b36d591720 ("powerpc/64: Don't trace code that runs with the soft irq mask unreconciled") Fixes: 9b81c0211c24 ("powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely") Fixes: 7c0482e3d055 ("powerpc/irq: Fix another case of lazy IRQ state getting out of sync") Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190708061046.7075-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/64: Don't trace code that runs with the soft irq mask unreconciled

2019-05-02T15:58:11+00:00

"Reconciling" in terms of interrupt handling, is to bring the soft irq mask state in to synch with the hardware, after an interrupt causes MSR[EE] to be cleared (while the soft mask may be enabled, and hard irqs not marked disabled). General kernel code should not be called while unreconciled, because local_irq_disable, etc. manipulations can cause surprising irq traces, and it's fragile because the soft irq code does not really expect to be called in this situation. When exiting from an interrupt, MSR[EE] is cleared to prevent races, but soft irq state is enabled for the returned-to context, so this is now an unreconciled state. restore_math is called in this state, and that can be ftraced, and the ftrace subsystem disables local irqs. Mark restore_math and its callees as notrace. Restore a sanity check in the soft irq code that had to be disabled for this case, by commit 4da1f79227ad4 ("powerpc/64: Disable irq restore warning for now"). Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc/irq: drop __irq_offset_value

2019-05-02T15:58:11+00:00

This patch drops__irq_offset_value which has not been used since commit 9c4cb8251513 ("powerpc: Remove use of CONFIG_PPC_MERGE") This removes a sparse warning. Fixes: 9c4cb8251513 ("powerpc: Remove use of CONFIG_PPC_MERGE") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: clean stack pointers naming

2019-02-23T11:31:40+00:00

Some stack pointers used to also be thread_info pointers and were called tp. Now that they are only stack pointers, rename them sp. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: regain entire stack space

2019-02-23T11:31:40+00:00

thread_info is not anymore in the stack, so the entire stack can now be used. There is also no risk anymore of corrupting task_cpu(p) with a stack overflow so the patch removes the test. When doing this, an explicit test for NULL stack pointer is needed in validate_sp() as it is not anymore implicitely covered by the sizeof(thread_info) gap. In the meantime, with the previous patch all pointers to the stacks are not anymore pointers to thread_info so this patch changes them to void* Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: Activate CONFIG_THREAD_INFO_IN_TASK

2019-02-23T11:31:40+00:00

This patch activates CONFIG_THREAD_INFO_IN_TASK which moves the thread_info into task_struct. Moving thread_info into task_struct has the following advantages: - It protects thread_info from corruption in the case of stack overflows. - Its address is harder to determine if stack addresses are leaked, making a number of attacks more difficult. This has the following consequences: - thread_info is now located at the beginning of task_struct. - The 'cpu' field is now in task_struct, and only exists when CONFIG_SMP is active. - thread_info doesn't have anymore the 'task' field. This patch: - Removes all recopy of thread_info struct when the stack changes. - Changes the CURRENT_THREAD_INFO() macro to point to current. - Selects CONFIG_THREAD_INFO_IN_TASK. - Modifies raw_smp_processor_id() to get ->cpu from current without including linux/sched.h to avoid circular inclusion and without including asm/asm-offsets.h to avoid symbol names duplication between ASM constants and C constants. - Modifies klp_init_thread_info() to take a task_struct pointer argument. Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin [mpe: Add task_stack.h to livepatch.h to fix build fails] Signed-off-by: Michael Ellerman

powerpc: Don't use CURRENT_THREAD_INFO to find the stack

2019-02-23T11:31:40+00:00

A few places use CURRENT_THREAD_INFO, or the C version, to find the stack. This will no longer work with THREAD_INFO_IN_TASK so change them to find the stack in other ways. Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman

powerpc/irq: use memblock functions returning virtual address

2019-02-23T11:31:39+00:00

Since only the virtual address of allocated blocks is used, lets use functions returning directly virtual address. Those functions have the advantage of also zeroing the block. Suggested-by: Mike Rapoport Signed-off-by: Christophe Leroy Acked-by: Mike Rapoport Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc/irq: drop arch_early_irq_init()

2019-01-14T09:39:27+00:00

arch_early_irq_init() does nothing different than the weak arch_early_irq_init() in kernel/softirq.c Fixes: 089fb442f301 ("powerpc: Use ARCH_IRQ_INIT_FLAGS") Signed-off-by: Christophe Leroy Acked-by: Thomas Gleixner Signed-off-by: Michael Ellerman