From: Dan Williams <dan.j.williams@intel.com>
To: mingo@redhat.com
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
kexec@lists.infradead.org, x86@kernel.org
Subject: [PATCH v3 3/4] efi: Fix efi_memmap_alloc() leaks
Date: Wed, 01 Jan 2020 20:13:33 -0800 [thread overview]
Message-ID: <157793841381.977550.3798473750871197840.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <157793839827.977550.7845382457971215205.stgit@dwillia2-desk3.amr.corp.intel.com>
With efi_fake_memmap() and efi_arch_mem_reserve() the efi table may be
updated and replaced multiple times. When that happens a previous
dynamically allocated efi memory map can be garbage collected. Use the
new EFI_MEMMAP_{SLAB,MEMBLOCK} flags to detect when a dynamically
allocated memory map is being replaced.
Debug statements in efi_memmap_free() reveal:
efi: __efi_memmap_free:37: phys: 0x23ffdd580 size: 2688 flags: 0x2
efi: __efi_memmap_free:37: phys: 0x9db00 size: 2640 flags: 0x2
efi: __efi_memmap_free:37: phys: 0x9e580 size: 2640 flags: 0x2
...a savings of 7968 bytes on a qemu boot with 2 entries specified to
efi_fake_mem=.
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/firmware/efi/memmap.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 2b81ee6858a9..46c8b4056cc1 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -29,6 +29,28 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
return PFN_PHYS(page_to_pfn(p));
}
+static void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags)
+{
+ if (flags & EFI_MEMMAP_MEMBLOCK) {
+ if (slab_is_available())
+ memblock_free_late(phys, size);
+ else
+ memblock_free(phys, size);
+ } else if (flags & EFI_MEMMAP_SLAB) {
+ struct page *p = pfn_to_page(PHYS_PFN(phys));
+ unsigned int order = get_order(size);
+
+ free_pages((unsigned long) page_address(p), order);
+ }
+}
+
+static void __init efi_memmap_free(void)
+{
+ __efi_memmap_free(efi.memmap.phys_map,
+ efi.memmap.desc_size * efi.memmap.nr_map,
+ efi.memmap.flags);
+}
+
/**
* efi_memmap_alloc - Allocate memory for the EFI memory map
* @num_entries: Number of entries in the allocated map.
@@ -90,6 +112,8 @@ __efi_memmap_init(struct efi_memory_map_data *data, unsigned long flags)
return -ENOMEM;
}
+ efi_memmap_free();
+
map.phys_map = data->phys_map;
map.nr_map = data->size / data->desc_size;
map.map_end = map.map + data->size;
next prev parent reply other threads:[~2020-01-02 4:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-02 4:13 [PATCH v3 0/4] efi: Fix handling of multiple efi_fake_mem= entries Dan Williams
2020-01-02 4:13 ` [PATCH v3 1/4] efi: Add a flags parameter to efi_memory_map Dan Williams
2020-01-02 4:13 ` [PATCH v3 2/4] efi: Add tracking for dynamically allocated memmaps Dan Williams
2020-01-02 9:02 ` Ard Biesheuvel
2020-01-06 19:05 ` Dan Williams
2020-01-02 4:13 ` Dan Williams [this message]
2020-01-02 4:13 ` [PATCH v3 4/4] efi: Fix handling of multiple efi_fake_mem= entries Dan Williams
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