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Date: Wed, 20 Jun 2018 15:09:28 -0700
From: Rick Edgecombe <rick.p.edgecombe@...el.com>
To: tglx@...utronix.de,
mingo@...hat.com,
hpa@...or.com,
x86@...nel.org,
linux-kernel@...r.kernel.org,
linux-mm@...ck.org,
kernel-hardening@...ts.openwall.com
Cc: kristen.c.accardi@...el.com,
dave.hansen@...el.com,
arjan.van.de.ven@...el.com,
Rick Edgecombe <rick.p.edgecombe@...el.com>
Subject: [PATCH 1/3] vmalloc: Add __vmalloc_node_try_addr function
Create __vmalloc_node_try_addr function that tries to allocate at a specific
address. The implementation relies on __vmalloc_node_range for the bulk of the
work. To keep this function from spamming the logs when an allocation failure
is fails, __vmalloc_node_range is changed to only warn when __GFP_NOWARN is not
set. This behavior is consistent with this flags interpretation in
alloc_vmap_area.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@...el.com>
---
include/linux/vmalloc.h | 3 +++
mm/vmalloc.c | 41 +++++++++++++++++++++++++++++++++++++++--
2 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 398e9c9..6eaa896 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -82,6 +82,9 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long start, unsigned long end, gfp_t gfp_mask,
pgprot_t prot, unsigned long vm_flags, int node,
const void *caller);
+extern void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size,
+ gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags,
+ int node, const void *caller);
#ifndef CONFIG_MMU
extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
static inline void *__vmalloc_node_flags_caller(unsigned long size, int node,
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index cfea25b..9e0820c9 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1710,6 +1710,42 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
}
/**
+ * __vmalloc_try_addr - try to alloc at a specific address
+ * @addr: address to try
+ * @size: size to try
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
+ * @node: node to use for allocation or NUMA_NO_NODE
+ * @caller: caller's return address
+ *
+ * Try to allocate at the specific address. If it succeeds the address is
+ * returned. If it fails NULL is returned. It may trigger TLB flushes.
+ */
+void *__vmalloc_node_try_addr(unsigned long addr, unsigned long size,
+ gfp_t gfp_mask, pgprot_t prot, unsigned long vm_flags,
+ int node, const void *caller)
+{
+ unsigned long addr_end;
+ unsigned long vsize = PAGE_ALIGN(size);
+
+ if (!vsize || (vsize >> PAGE_SHIFT) > totalram_pages)
+ return NULL;
+
+ if (!(vm_flags & VM_NO_GUARD))
+ vsize += PAGE_SIZE;
+
+ addr_end = addr + vsize;
+
+ if (addr > addr_end)
+ return NULL;
+
+ return __vmalloc_node_range(size, 1, addr, addr_end,
+ gfp_mask | __GFP_NOWARN, prot, vm_flags, node,
+ caller);
+}
+
+/**
* __vmalloc_node_range - allocate virtually contiguous memory
* @size: allocation size
* @align: desired alignment
@@ -1759,8 +1795,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
return addr;
fail:
- warn_alloc(gfp_mask, NULL,
- "vmalloc: allocation failure: %lu bytes", real_size);
+ if (!(gfp_mask & __GFP_NOWARN))
+ warn_alloc(gfp_mask, NULL,
+ "vmalloc: allocation failure: %lu bytes", real_size);
return NULL;
}
--
2.7.4
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