Changes since v2 [1]: - Move the efi_memmap_free() until efi_memmap_install() is committed to installing the new map. (Dave). - Handle the case of a memblock allocated memmap being freed after the slab allocator is up. Just use memblock_free_late() for that case rather than warn. (Prompted by Dave's feedback on how many successful efi_memmap_free() calls occur during a boot). - Not changed was anything additional related to Dave's concern about efi_fake_mem= being applied to overlapping entries. I tested "efi_fake_mem=4G@9G:0x40000,4G@12G:0x40000" which triggers the second entry to overwrite the first as well as another entry. The result is reasonable and functional for what is otherwise garbage input: efi: mem53: [Conventional Memory| | |SP| | | | | | |WB|WT|WC|UC] range=[0x240000000-0x2ffffffff] (3072MB) efi: mem54: [Conventional Memory| | |SP| | | | | | |WB|WT|WC|UC] range=[0x300000000-0x33fffffff] (1024MB) efi: mem55: [Conventional Memory| | |SP| | | | | | |WB|WT|WC|UC] range=[0x340000000-0x3ffffffff] (3072MB) efi: mem56: [Conventional Memory| | | | | | | | | |WB|WT|WC|UC] range=[0x400000000-0x43fffffff] (1024MB) # cat /proc/iomem | grep Sof 240000000-3ffffffff : Soft Reserved [1]: http://lore.kernel.org/r/157782985777.367056.14741265874314204783.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx --- While testing an upcoming patchset to enhance the "soft reservation" implementation it started crashing when rebased on v5.5-rc3. This uncovered a few bugs in the efi_fake_mem= handling and efi_memmap_alloc() leaks. --- Copied from patch4: Dave noticed that when specifying multiple efi_fake_mem= entries only the last entry was successfully being reflected in the efi memory map. This is due to the fact that the efi_memmap_insert() is being called multiple times, but on successive invocations the insertion should be applied to the last new memmap rather than the original map at efi_fake_memmap() entry. Rework efi_fake_memmap() to install the new memory map after each efi_fake_mem= entry is parsed. This also fixes an issue in efi_fake_memmap() that caused it to litter emtpy entries into the end of the efi memory map. The empty entry causes efi_memmap_insert() to attempt more memmap splits / copies than efi_memmap_split_count() accounted for when sizing the new map. BUG: unable to handle page fault for address: ffffffffff281000 [..] RIP: 0010:efi_memmap_insert+0x11d/0x191 [..] Call Trace: ? bgrt_init+0xbe/0xbe ? efi_arch_mem_reserve+0x1cb/0x228 ? acpi_parse_bgrt+0xa/0xd ? acpi_table_parse+0x86/0xb8 ? acpi_boot_init+0x494/0x4e3 ? acpi_parse_x2apic+0x87/0x87 ? setup_acpi_sci+0xa2/0xa2 ? setup_arch+0x8db/0x9e1 ? start_kernel+0x6a/0x547 ? secondary_startup_64+0xb6/0xc0 Commit af1648984828 "x86/efi: Update e820 with reserved EFI boot services data to fix kexec breakage" is listed in Fixes: since it introduces more occurrences where efi_memmap_insert() is invoked after an efi_fake_mem= configuration has been parsed. Previously the side effects of vestigial empty entries were benign, but with commit af1648984828 that follow-on efi_memmap_insert() invocation triggers the above crash signature. --- Dan Williams (4): efi: Add a flags parameter to efi_memory_map efi: Add tracking for dynamically allocated memmaps efi: Fix efi_memmap_alloc() leaks efi: Fix handling of multiple efi_fake_mem= entries arch/x86/platform/efi/efi.c | 2 + arch/x86/platform/efi/quirks.c | 11 ++++--- drivers/firmware/efi/fake_mem.c | 37 +++++++++++++------------ drivers/firmware/efi/memmap.c | 58 ++++++++++++++++++++++++++++++--------- include/linux/efi.h | 13 +++++++-- 5 files changed, 81 insertions(+), 40 deletions(-) _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
