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Bottomley" , Helge Deller , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , "David S. Miller" , Andreas Larsson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Muchun Song , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , Shuah Khan , Christoph Hellwig , Michal Hocko , "Kirill A. Shutemov" , Chris Torek Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-abi-devel@lists.sourceforge.net, Charlie Jenkins X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1348; i=charlie@rivosinc.com; h=from:subject:message-id; bh=B2nFsYQPUa93R6MPC6rybC4BjlmBU89eB/xyA3tmSh8=; b=owGbwMvMwCHWx5hUnlvL8Y3xtFoSQ9ot+em/OZQnfrnX8ed38Mt7a5qeTLghH2JpoLVOM/lWE E9Dee3VjlIWBjEOBlkxRRaeaw3MrXf0y46Klk2AmcPKBDKEgYtTACbS9pyRoX//nRvvVlydp7Xm 8/1ihzrxA51eb31tEvRWPpi166jgtMMM/2Pui4Sr/NDPPh503bbDcC77kZANfKUH/kz3LrfLiU2 exg4A X-Developer-Key: i=charlie@rivosinc.com; a=openpgp; fpr=7D834FF11B1D8387E61C776FFB10D1F27D6B1354 Create a personality flag ADDR_LIMIT_47BIT to support applications that wish to transition from running in environments that support at most 47-bit VAs to environments that support larger VAs. This personality can be set to cause all allocations to be below the 47-bit boundary. Using MAP_FIXED with mmap() will bypass this restriction. Signed-off-by: Charlie Jenkins --- include/uapi/linux/personality.h | 1 + mm/mmap.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/include/uapi/linux/personality.h b/include/uapi/linux/personality.h index 49796b7756af..cd3b8c154d9b 100644 --- a/include/uapi/linux/personality.h +++ b/include/uapi/linux/personality.h @@ -22,6 +22,7 @@ enum { WHOLE_SECONDS = 0x2000000, STICKY_TIMEOUTS = 0x4000000, ADDR_LIMIT_3GB = 0x8000000, + ADDR_LIMIT_47BIT = 0x10000000, }; /* diff --git a/mm/mmap.c b/mm/mmap.c index d0dfc85b209b..a5c7544853e5 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1766,6 +1766,9 @@ unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info) { unsigned long addr; + if (current->personality & ADDR_LIMIT_47BIT) + info->high_limit = MIN(info->high_limit, BIT(47) - 1); + if (info->flags & VM_UNMAPPED_AREA_TOPDOWN) addr = unmapped_area_topdown(info); else