diff options
Diffstat (limited to 'debian/patches-rt/0061-mm-highmem-Take-kmap_high_get-properly-into-account.patch')
| -rw-r--r-- | debian/patches-rt/0061-mm-highmem-Take-kmap_high_get-properly-into-account.patch | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/debian/patches-rt/0061-mm-highmem-Take-kmap_high_get-properly-into-account.patch b/debian/patches-rt/0061-mm-highmem-Take-kmap_high_get-properly-into-account.patch new file mode 100644 index 000000000..5970ff263 --- /dev/null +++ b/debian/patches-rt/0061-mm-highmem-Take-kmap_high_get-properly-into-account.patch @@ -0,0 +1,72 @@ +From 3df53841fc978eae47eb80dbb4ccaefa880589a7 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 12 Nov 2020 11:59:32 +0100 +Subject: [PATCH 061/323] mm/highmem: Take kmap_high_get() properly into + account +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +kunmap_local() warns when the virtual address to unmap is below +PAGE_OFFSET. This is correct except for the case that the mapping was +obtained via kmap_high_get() because the PKMAP addresses are right below +PAGE_OFFSET. + +Cure it by skipping the WARN_ON() when the unmap was handled by +kunmap_high(). + +Fixes: 298fa1ad5571 ("highmem: Provide generic variant of kmap_atomic*") +Reported-by: vtolkm@googlemail.com +Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> +Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Cc: Andrew Morton <akpm@linux-foundation.org> +Link: https://lore.kernel.org/r/87y2j6n8mj.fsf@nanos.tec.linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + mm/highmem.c | 19 +++++++++++++------ + 1 file changed, 13 insertions(+), 6 deletions(-) + +diff --git a/mm/highmem.c b/mm/highmem.c +index 8db577e5290c..72b9a2d95c72 100644 +--- a/mm/highmem.c ++++ b/mm/highmem.c +@@ -422,12 +422,15 @@ static inline void *arch_kmap_local_high_get(struct page *page) + #endif + + /* Unmap a local mapping which was obtained by kmap_high_get() */ +-static inline void kmap_high_unmap_local(unsigned long vaddr) ++static inline bool kmap_high_unmap_local(unsigned long vaddr) + { + #ifdef ARCH_NEEDS_KMAP_HIGH_GET +- if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) ++ if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { + kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); ++ return true; ++ } + #endif ++ return false; + } + + static inline int kmap_local_calc_idx(int idx) +@@ -493,10 +496,14 @@ void kunmap_local_indexed(void *vaddr) + + if (addr < __fix_to_virt(FIX_KMAP_END) || + addr > __fix_to_virt(FIX_KMAP_BEGIN)) { +- WARN_ON_ONCE(addr < PAGE_OFFSET); +- +- /* Handle mappings which were obtained by kmap_high_get() */ +- kmap_high_unmap_local(addr); ++ /* ++ * Handle mappings which were obtained by kmap_high_get() ++ * first as the virtual address of such mappings is below ++ * PAGE_OFFSET. Warn for all other addresses which are in ++ * the user space part of the virtual address space. ++ */ ++ if (!kmap_high_unmap_local(addr)) ++ WARN_ON_ONCE(addr < PAGE_OFFSET); + return; + } + +-- +2.43.0 + |