linux/arch
Danilo Krummrich 590b9d576c mm: kvmalloc: align kvrealloc() with krealloc()
Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:

 - krealloc() frees the memory when the requested size is zero, whereas
   kvrealloc() simply returns a pointer to the existing allocation.

 - krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
   kvrealloc() does not accept a NULL pointer at all and, if passed,
   would fault instead.

 - krealloc() is self-contained, whereas kvrealloc() relies on the caller
   to provide the size of the previous allocation.

Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.

Besides that, implementing kvrealloc() by making use of krealloc() and
vrealloc() provides oppertunities to grow (and shrink) allocations more
efficiently.  For instance, vrealloc() can be optimized to allocate and
map additional pages to grow the allocation or unmap and free unused pages
to shrink the allocation.

[dakr@kernel.org: document concurrency restrictions]
  Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: disable KASAN when switching to vmalloc]
  Link: https://lkml.kernel.org/r/20240730185049.6244-2-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
  Link: https://lkml.kernel.org/r/20240730185049.6244-5-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:44 -07:00
..
alpha alpha: fix ioread64be()/iowrite64be() helpers 2024-08-01 15:48:03 +02:00
arc arc: convert to generic syscall table 2024-07-10 14:23:38 +02:00
arm i.MX fixes for 6.11: 2024-08-28 20:27:29 +00:00
arm64 mm: kvmalloc: align kvrealloc() with krealloc() 2024-09-01 20:25:44 -07:00
csky ftrace: Rewrite of function graph tracer 2024-07-18 13:36:33 -07:00
hexagon hexagon: use new system call table 2024-07-10 14:23:38 +02:00
loongarch LoongArch: KVM: Invalidate guest steal time address on vCPU reset 2024-08-26 23:11:32 +08:00
m68k Kbuild updates for v6.11 2024-07-23 14:32:21 -07:00
microblaze microblaze: don't treat zero reserved memory regions as error 2024-08-25 15:26:30 -07:00
mips Revert "MIPS: csrc-r4k: Apply verification clocksource flags" 2024-08-25 15:26:30 -07:00
nios2 Kbuild updates for v6.11 2024-07-23 14:32:21 -07:00
openrisc openrisc: convert to generic syscall table 2024-07-10 14:23:38 +02:00
parisc parisc: fix a possible DMA corruption 2024-07-29 16:19:07 +02:00
powerpc mm: kvmalloc: align kvrealloc() with krealloc() 2024-09-01 20:25:44 -07:00
riscv Merge patch series "RISC-V: hwprobe: Misaligned scalar perf fix and rename" 2024-08-15 13:12:21 -07:00
s390 s390 updates for 6.11-rc5 2024-08-25 12:05:23 +12:00
sh sh updates for v6.11 2024-07-23 11:57:52 -07:00
sparc Driver core changes for 6.11-rc1 2024-07-25 10:42:22 -07:00
um minmax: make generic MIN() and MAX() macros available everywhere 2024-07-28 15:49:18 -07:00
x86 KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
xtensa - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
.gitignore
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