6.6-stable review patch. If anyone has any objections, please let me know.
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From: Heiko Carstens hca@linux.ibm.com
[ Upstream commit 2835f8bf5530750c3381166005934f996a83ad05 ]
kernel_page_present() was intentionally not implemented when adding ARCH_HAS_SET_DIRECT_MAP support, since it was only used for suspend/resume which is not supported anymore on s390.
A new bpf use case led to a compile error specific to s390. Even though this specific use case went away implement kernel_page_present(), so that the API is complete and potential future users won't run into this problem.
Reported-by: Daniel Borkmann daniel@iogearbox.net Closes: https://lore.kernel.org/all/045de961-ac69-40cc-b141-ab70ec9377ec@iogearbox.n... Fixes: 0490d6d7ba0a ("s390/mm: enable ARCH_HAS_SET_DIRECT_MAP") Reviewed-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/include/asm/set_memory.h | 1 + arch/s390/mm/pageattr.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+)
diff --git a/arch/s390/include/asm/set_memory.h b/arch/s390/include/asm/set_memory.h index 06fbabe2f66c9..cb4cc0f59012f 100644 --- a/arch/s390/include/asm/set_memory.h +++ b/arch/s390/include/asm/set_memory.h @@ -62,5 +62,6 @@ __SET_MEMORY_FUNC(set_memory_4k, SET_MEMORY_4K)
int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page);
#endif diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index 441f654d048d2..44271835c97e7 100644 --- a/arch/s390/mm/pageattr.c +++ b/arch/s390/mm/pageattr.c @@ -406,6 +406,21 @@ int set_direct_map_default_noflush(struct page *page) return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF); }
+bool kernel_page_present(struct page *page) +{ + unsigned long addr; + unsigned int cc; + + addr = (unsigned long)page_address(page); + asm volatile( + " lra %[addr],0(%[addr])\n" + " ipm %[cc]\n" + : [cc] "=d" (cc), [addr] "+a" (addr) + : + : "cc"); + return (cc >> 28) == 0; +} + #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
static void ipte_range(pte_t *pte, unsigned long address, int nr)