From: Dave Young <dyoung@redhat.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: mingo@redhat.com, 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: Re: [PATCH v2 3/4] efi: Fix efi_memmap_alloc() leaks
Date: Wed, 1 Jan 2020 11:35:17 +0800 [thread overview]
Message-ID: <20200101033517.GB14346@dhcp-128-65.nay.redhat.com> (raw)
In-Reply-To: <157782987346.367056.16932641815225610530.stgit@dwillia2-desk3.amr.corp.intel.com>
Hi Dan,
On 12/31/19 at 02:04pm, Dan Williams wrote:
> 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.
>
> 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..188ab3cd5c52 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 (WARN_ON(slab_is_available() && (flags & EFI_MEMMAP_MEMBLOCK)))
> + return;
> +
> + if (flags & EFI_MEMMAP_MEMBLOCK) {
> + 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.
> @@ -209,6 +231,8 @@ int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map,
> data.desc_size = efi.memmap.desc_size;
> flags |= efi.memmap.flags & EFI_MEMMAP_LATE;
>
> + efi_memmap_free();
> +
> return __efi_memmap_init(&data, flags);
Hmm, only free the memmap in case __efi_memmap_init succeeded..
Thanks
Dave
next prev parent reply other threads:[~2020-01-01 3:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-31 22:04 [PATCH v2 0/4] efi: Fix handling of multiple efi_fake_mem= entries Dan Williams
2019-12-31 22:04 ` [PATCH v2 1/4] efi: Add a flags parameter to efi_memory_map Dan Williams
2019-12-31 22:04 ` [PATCH v2 2/4] efi: Add tracking for dynamically allocated memmaps Dan Williams
2019-12-31 22:04 ` [PATCH v2 3/4] efi: Fix efi_memmap_alloc() leaks Dan Williams
2020-01-01 3:35 ` Dave Young [this message]
2020-01-01 4:52 ` Dan Williams
2019-12-31 22:04 ` [PATCH v2 4/4] efi: Fix handling of multiple efi_fake_mem= entries Dan Williams
2020-01-01 4:51 ` Dave Young
2020-01-01 5:04 ` Dan Williams
2020-01-01 6:15 ` Dave Young
2020-01-01 6:20 ` Dave Young
2020-01-01 18:36 ` Dan Williams
2020-01-02 2:21 ` Dave Young
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