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54c95a11cc
In order to avoid wasting user address space by using bottom-up mmap allocation scheme, prefer top-down scheme when possible. Before: root@qemuriscv64:~# cat /proc/self/maps 00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils 00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils 00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils 00018000-00039000 rw-p 00000000 00:00 0 [heap] 1555556000-155556d000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so 155556d000-155556e000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so 155556e000-155556f000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so 155556f000-1555570000 rw-p 00000000 00:00 0 1555570000-1555572000 r-xp 00000000 00:00 0 [vdso] 1555574000-1555576000 rw-p 00000000 00:00 0 1555576000-1555674000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so 1555674000-1555678000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so 1555678000-155567a000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so 155567a000-15556a0000 rw-p 00000000 00:00 0 3fffb90000-3fffbb1000 rw-p 00000000 00:00 0 [stack] After: root@qemuriscv64:~# cat /proc/self/maps 00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils 00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils 00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils 2de81000-2dea2000 rw-p 00000000 00:00 0 [heap] 3ff7eb6000-3ff7ed8000 rw-p 00000000 00:00 0 3ff7ed8000-3ff7fd6000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so 3ff7fd6000-3ff7fda000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so 3ff7fda000-3ff7fdc000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so 3ff7fdc000-3ff7fe2000 rw-p 00000000 00:00 0 3ff7fe4000-3ff7fe6000 r-xp 00000000 00:00 0 [vdso] 3ff7fe6000-3ff7ffd000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so 3ff7ffd000-3ff7ffe000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so 3ff7ffe000-3ff7fff000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so 3ff7fff000-3ff8000000 rw-p 00000000 00:00 0 3fff888000-3fff8a9000 rw-p 00000000 00:00 0 [stack] [alex@ghiti.fr: v6] Link: http://lkml.kernel.org/r/20190808061756.19712-15-alex@ghiti.fr Link: http://lkml.kernel.org/r/20190730055113.23635-15-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Paul Walmsley <paul.walmsley@sifive.com> [arch/riscv] Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: James Hogan <jhogan@kernel.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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arm | ||
arm64 | ||
c6x | ||
csky | ||
h8300 | ||
hexagon | ||
ia64 | ||
m68k | ||
microblaze | ||
mips | ||
nds32 | ||
nios2 | ||
openrisc | ||
parisc | ||
powerpc | ||
riscv | ||
s390 | ||
sh | ||
sparc | ||
um | ||
unicore32 | ||
x86 | ||
xtensa | ||
.gitignore | ||
Kconfig |