From: Song Liu <song@kernel.org>
To: <bpf@vger.kernel.org>, <linux-mm@kvack.org>
Cc: <akpm@linux-foundation.org>, <x86@kernel.org>,
<peterz@infradead.org>, <hch@lst.de>,
<rick.p.edgecombe@intel.com>, <aaron.lu@intel.com>,
<rppt@kernel.org>, <mcgrof@kernel.org>,
Song Liu <song@kernel.org>
Subject: [PATCH bpf-next v2 4/5] vmalloc: introduce register_text_tail_vm()
Date: Mon, 7 Nov 2022 14:39:20 -0800 [thread overview]
Message-ID: <20221107223921.3451913-5-song@kernel.org> (raw)
In-Reply-To: <20221107223921.3451913-1-song@kernel.org>
Allow arch code to register some memory to be used by execmem_alloc().
One possible use case is to allocate PMD pages for kernl text up to
PMD_ALIGN(_etext), and use (_etext, PMD_ALIGN(_etext)) for
execmem_alloc. Currently, only one such region is supported.
Signed-off-by: Song Liu <song@kernel.org>
---
include/linux/vmalloc.h | 4 ++++
mm/vmalloc.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 30aa8c187d40..2babbe3031a5 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -132,11 +132,15 @@ extern void vm_unmap_aliases(void);
#ifdef CONFIG_MMU
extern void __init vmalloc_init(void);
extern unsigned long vmalloc_nr_pages(void);
+void register_text_tail_vm(unsigned long start, unsigned long end);
#else
static inline void vmalloc_init(void)
{
}
static inline unsigned long vmalloc_nr_pages(void) { return 0; }
+void register_text_tail_vm(unsigned long start, unsigned long end)
+{
+}
#endif
extern void *vmalloc(unsigned long size) __alloc_size(1);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6cc72c795ee5..cb54bce3725e 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -77,6 +77,9 @@ static const bool vmap_allow_huge = false;
#endif
#define PMD_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PMD_SIZE)
+static struct vm_struct text_tail_vm;
+static struct vmap_area text_tail_va;
+
bool is_vmalloc_addr(const void *x)
{
unsigned long addr = (unsigned long)kasan_reset_tag(x);
@@ -655,6 +658,8 @@ int is_vmalloc_or_module_addr(const void *x)
unsigned long addr = (unsigned long)kasan_reset_tag(x);
if (addr >= MODULES_VADDR && addr < MODULES_END)
return 1;
+ if (addr >= text_tail_va.va_start && addr < text_tail_va.va_end)
+ return 1;
#endif
return is_vmalloc_addr(x);
}
@@ -2439,6 +2444,35 @@ static void vmap_init_free_space(void)
}
}
+/*
+ * register_text_tail_vm() allows arch code to register memory regions
+ * for execmem_alloc. Unlike regular memory regions used by execmem_alloc,
+ * this region is never freed by vfree_exec.
+ *
+ * One possible use case is to allocate PMD pages for kernl text up to
+ * PMD_ALIGN(_etext), and use (_etext, PMD_ALIGN(_etext)) for
+ * execmem_alloc.
+ */
+void register_text_tail_vm(unsigned long start, unsigned long end)
+{
+ struct vmap_area *va;
+
+ /* only support one region */
+ if (WARN_ON_ONCE(text_tail_vm.addr))
+ return;
+
+ va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+ if (WARN_ON_ONCE(!va))
+ return;
+ text_tail_vm.addr = (void *)start;
+ text_tail_vm.size = end - start;
+ text_tail_va.va_start = start;
+ text_tail_va.va_end = end;
+ text_tail_va.vm = &text_tail_vm;
+ memcpy(va, &text_tail_va, sizeof(*va));
+ insert_vmap_area_augment(va, NULL, &free_text_area_root, &free_text_area_list);
+}
+
void __init vmalloc_init(void)
{
struct vmap_area *va;
--
2.30.2
next prev parent reply other threads:[~2022-11-07 22:42 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-07 22:39 [PATCH bpf-next v2 0/5] execmem_alloc for BPF programs Song Liu
2022-11-07 22:39 ` [PATCH bpf-next v2 1/5] vmalloc: introduce execmem_alloc, execmem_free, and execmem_fill Song Liu
2022-11-07 22:39 ` [PATCH bpf-next v2 2/5] x86/alternative: support execmem_alloc() and execmem_free() Song Liu
2022-11-07 22:39 ` [PATCH bpf-next v2 3/5] bpf: use execmem_alloc for bpf program and bpf dispatcher Song Liu
2022-11-07 22:39 ` Song Liu [this message]
2022-11-07 22:39 ` [PATCH bpf-next v2 5/5] x86: use register_text_tail_vm Song Liu
2022-11-08 19:04 ` Edgecombe, Rick P
2022-11-08 22:15 ` Song Liu
2022-11-15 17:28 ` Edgecombe, Rick P
2022-11-07 22:55 ` [PATCH bpf-next v2 0/5] execmem_alloc for BPF programs Luis Chamberlain
2022-11-07 23:13 ` Song Liu
2022-11-07 23:39 ` Luis Chamberlain
2022-11-08 0:13 ` Edgecombe, Rick P
2022-11-08 2:45 ` Luis Chamberlain
2022-11-08 18:20 ` Song Liu
2022-11-08 18:12 ` Song Liu
2022-11-08 11:27 ` Mike Rapoport
2022-11-08 12:38 ` Aaron Lu
2022-11-09 6:55 ` Christoph Hellwig
2022-11-09 11:05 ` Peter Zijlstra
2022-11-08 16:51 ` Edgecombe, Rick P
2022-11-08 18:50 ` Song Liu
2022-11-09 11:17 ` Mike Rapoport
2022-11-09 17:04 ` Edgecombe, Rick P
2022-11-09 17:53 ` Song Liu
2022-11-13 10:34 ` Mike Rapoport
2022-11-14 20:30 ` Song Liu
2022-11-15 21:18 ` Luis Chamberlain
2022-11-15 21:39 ` Edgecombe, Rick P
2022-11-16 22:34 ` Luis Chamberlain
2022-11-17 8:50 ` Mike Rapoport
2022-11-17 18:36 ` Song Liu
2022-11-20 10:41 ` Mike Rapoport
2022-11-21 14:52 ` Song Liu
2022-11-30 9:39 ` Mike Rapoport
2022-11-09 17:43 ` Song Liu
2022-11-09 21:23 ` Christophe Leroy
2022-11-10 1:50 ` Song Liu
2022-11-13 10:42 ` Mike Rapoport
2022-11-14 20:45 ` Song Liu
2022-11-15 20:51 ` Luis Chamberlain
2022-11-20 10:44 ` Mike Rapoport
2022-11-08 18:41 ` Song Liu
2022-11-08 19:43 ` Christophe Leroy
2022-11-08 21:40 ` Song Liu
2022-11-13 9:58 ` Mike Rapoport
2022-11-14 20:13 ` Song Liu
2022-11-08 11:44 ` Christophe Leroy
2022-11-08 18:47 ` Song Liu
2022-11-08 19:32 ` Christophe Leroy
2022-11-08 11:48 ` Mike Rapoport
2022-11-15 1:30 ` Song Liu
2022-11-15 17:34 ` Edgecombe, Rick P
2022-11-15 21:54 ` Song Liu
2022-11-15 22:14 ` Edgecombe, Rick P
2022-11-15 22:32 ` Song Liu
2022-11-16 1:20 ` Song Liu
2022-11-16 21:22 ` Edgecombe, Rick P
2022-11-16 22:03 ` Song Liu
2022-11-15 21:09 ` Luis Chamberlain
2022-11-15 21:32 ` Luis Chamberlain
2022-11-15 22:48 ` Song Liu
2022-11-16 22:33 ` Luis Chamberlain
2022-11-16 22:47 ` Edgecombe, Rick P
2022-11-16 23:53 ` Luis Chamberlain
2022-11-17 1:17 ` Song Liu
2022-11-17 9:37 ` Mike Rapoport
2022-11-29 10:23 ` Thomas Gleixner
2022-11-29 17:26 ` Song Liu
2022-11-29 23:56 ` Thomas Gleixner
2022-11-30 16:18 ` Song Liu
2022-12-01 9:08 ` Thomas Gleixner
2022-12-01 19:31 ` Song Liu
2022-12-02 1:38 ` Thomas Gleixner
2022-12-02 8:38 ` Song Liu
2022-12-02 9:22 ` Thomas Gleixner
2022-12-06 20:25 ` Song Liu
2022-12-07 15:36 ` Thomas Gleixner
2022-12-07 16:53 ` Christophe Leroy
2022-12-07 19:29 ` Song Liu
2022-12-07 21:04 ` Thomas Gleixner
2022-12-07 21:48 ` Christophe Leroy
2022-12-07 19:26 ` Song Liu
2022-12-07 20:57 ` Thomas Gleixner
2022-12-07 23:17 ` Song Liu
2022-12-02 10:46 ` Christophe Leroy
2022-12-02 17:43 ` Thomas Gleixner
2022-12-01 20:23 ` Mike Rapoport
2022-12-01 22:34 ` Thomas Gleixner
2022-12-03 14:46 ` Mike Rapoport
2022-12-03 20:58 ` Thomas Gleixner
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