diff options
Diffstat (limited to 'debian/patches-rt/0028-asm-generic-Provide-kmap_size.h.patch')
| -rw-r--r-- | debian/patches-rt/0028-asm-generic-Provide-kmap_size.h.patch | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/debian/patches-rt/0028-asm-generic-Provide-kmap_size.h.patch b/debian/patches-rt/0028-asm-generic-Provide-kmap_size.h.patch new file mode 100644 index 000000000..bb5d5f717 --- /dev/null +++ b/debian/patches-rt/0028-asm-generic-Provide-kmap_size.h.patch @@ -0,0 +1,70 @@ +From 5ed7d8c8905e639e711f1a21e5f978fc21585f8c Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Tue, 3 Nov 2020 10:27:17 +0100 +Subject: [PATCH 028/323] asm-generic: Provide kmap_size.h +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +kmap_types.h is a misnomer because the old atomic MAP based array does not +exist anymore and the whole indirection of architectures including +kmap_types.h is inconinstent and does not allow to provide guard page +debugging for this misfeature. + +Add a common header file which defines the mapping stack size for all +architectures. Will be used when converting architectures over to a +generic kmap_local/atomic implementation. + +The array size is chosen with the following constraints in mind: + + - The deepest nest level in one context is 3 according to code + inspection. + + - The worst case nesting for the upcoming reemptible version would be: + + 2 maps in task context and a fault inside + 2 maps in the fault handler + 3 maps in softirq + 2 maps in interrupt + +So a total of 16 is sufficient and probably overestimated. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + include/asm-generic/Kbuild | 1 + + include/asm-generic/kmap_size.h | 12 ++++++++++++ + 2 files changed, 13 insertions(+) + create mode 100644 include/asm-generic/kmap_size.h + +diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild +index d1300c6e0a47..3114a6da7e56 100644 +--- a/include/asm-generic/Kbuild ++++ b/include/asm-generic/Kbuild +@@ -31,6 +31,7 @@ mandatory-y += irq_regs.h + mandatory-y += irq_work.h + mandatory-y += kdebug.h + mandatory-y += kmap_types.h ++mandatory-y += kmap_size.h + mandatory-y += kprobes.h + mandatory-y += linkage.h + mandatory-y += local.h +diff --git a/include/asm-generic/kmap_size.h b/include/asm-generic/kmap_size.h +new file mode 100644 +index 000000000000..9d6c7786a645 +--- /dev/null ++++ b/include/asm-generic/kmap_size.h +@@ -0,0 +1,12 @@ ++/* SPDX-License-Identifier: GPL-2.0 */ ++#ifndef _ASM_GENERIC_KMAP_SIZE_H ++#define _ASM_GENERIC_KMAP_SIZE_H ++ ++/* For debug this provides guard pages between the maps */ ++#ifdef CONFIG_DEBUG_HIGHMEM ++# define KM_MAX_IDX 33 ++#else ++# define KM_MAX_IDX 16 ++#endif ++ ++#endif +-- +2.43.0 + |