Messages in this thread | | | Date | Wed, 1 Jan 2020 11:35:17 +0800 | From | Dave Young <> | Subject | Re: [PATCH v2 3/4] efi: Fix efi_memmap_alloc() leaks |
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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
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