kernel.git/arch/s390/boot, branch linux-6.4.y

s390/mm: fix direct map accounting

2023-04-13T15:36:28Z

Commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled") did not implement direct map accounting in the early page table setup code. In result the reported values are bogus now: $cat /proc/meminfo ... DirectMap4k: 5120 kB DirectMap1M: 18446744073709546496 kB DirectMap2G: 0 kB Fix this by adding the missing accounting. The result looks sane again: $cat /proc/meminfo ... DirectMap4k: 6156 kB DirectMap1M: 2091008 kB DirectMap2G: 6291456 kB Fixes: bb1520d581a3 ("s390/mm: start kernel with DAT enabled") Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm: rename POPULATE_ONE2ONE to POPULATE_DIRECT

2023-04-13T15:36:28Z

Architectures generally use the "direct map" wording for mapping the whole physical memory. Use that wording as well in arch/s390/boot/vmem.c, instead of "one to one" in order to avoid confusion. This also matches what is already done in arch/s390/mm/vmem.c. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/boot: improve install.sh script

2023-04-13T15:36:28Z

Use proper quoting for the variables and explicitly distinguish between command options and positional arguments. Acked-by: Heiko Carstens Signed-off-by: Marc Hartmayer Signed-off-by: Vasily Gorbik

s390/kaslr: randomize amode31 base address

2023-04-13T15:36:27Z

When the KASLR is enabled, randomize the base address of the amode31 image within the first 2 GB, similar to the approach taken for the vmlinux image. This makes it harder to predict the location of amode31 data and code. Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/kaslr: generalize and improve random base distribution

2023-04-13T15:36:27Z

Improve the distribution algorithm of random base address to ensure a uniformity among all suitable addresses. To generate a random value once, and to build a continuous range in which every value is suitable, count all the suitable addresses (referred to as positions) that can be used as a base address. The positions are counted by iterating over the usable memory ranges. For each range that is big enough to accommodate the image, count all the suitable addresses where the image can be placed, while taking reserved memory ranges into consideration. A new function "iterate_valid_positions()" has dual purpose. Firstly, it is called to count the positions in a given memory range, and secondly, to convert a random position back to an address. "get_random_base()" has been replaced with more generic "randomize_within_range()" which now could be called for randomizing base addresses not just for the kernel image. Acked-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/boot: pin amode31 default lma

2023-04-13T15:36:27Z

The special amode31 part of the kernel must always remain below 2Gb. Place it just under vmlinux.default_lma by default, which makes it easier to debug amode31 as its default lma is known 0x10000 - 0x3000 (currently, amode31's size is 3 pages). This location is always available as it is originally occupied by the vmlinux archive. Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/boot: do not change default_lma

2023-04-13T15:36:27Z

The current modification of the default_lma is illogical and should be avoided. It would be more appropriate to introduce and utilize a new variable vmlinux_lma instead, so that default_lma remains unchanged and at its original "default" value of 0x100000. Signed-off-by: Vasily Gorbik

s390/kaslr: provide kaslr_enabled() function

2023-04-13T15:36:25Z

Just like other architectures provide a kaslr_enabled() function, instead of directly accessing a global variable. Also pass the renamed __kaslr_enabled variable from the decompressor to the kernel, so that kalsr_enabled() is available there too. This will be used by a subsequent patch which randomizes the module base load address. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/kasan: move shadow mapping to decompressor

2023-03-20T10:02:51Z

Since regular paging structs are initialized in decompressor already move KASAN shadow mapping to decompressor as well. This helps to avoid allocating KASAN required memory in 1 large chunk, de-duplicate paging structs creation code and start the uncompressed kernel with KASAN instrumentation right away. This also allows to avoid all pitfalls accidentally calling KASAN instrumented code during KASAN initialization. Acked-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/boot: rework decompressor reserved tracking

2023-03-20T10:02:50Z

Currently several approaches for finding unused memory in decompressor are utilized. While "safe_addr" grows towards higher addresses, vmem code allocates paging structures top down. The former requires careful ordering. In addition to that ipl report handling code verifies potential intersections with secure boot certificates on its own. Neither of two approaches are memory holes aware and consistent with each other in low memory conditions. To solve that, existing approaches are generalized and combined together, as well as online memory ranges are now taken into consideration. physmem_info has been extended to contain reserved memory ranges. New set of functions allow to handle reserves and find unused memory. All reserves and memory allocations are "typed". In case of out of memory condition decompressor fails with detailed info on current reserved ranges and usable online memory. Linux version 6.2.0 ... Kernel command line: ... mem=100M Our of memory allocating 100000 bytes 100000 aligned in range 0:5800000 Reserved memory ranges: 0000000000000000 0000000003e33000 DECOMPRESSOR 0000000003f00000 00000000057648a3 INITRD 00000000063e0000 00000000063e8000 VMEM 00000000063eb000 00000000063f4000 VMEM 00000000063f7800 0000000006400000 VMEM 0000000005800000 0000000006300000 KASAN Usable online memory ranges (info source: sclp read info [3]): 0000000000000000 0000000006400000 Usable online memory total: 6400000 Reserved: 61b10a3 Free: 24ef5d Call Trace: (sp:000000000002bd58 [<0000000000012a70>] physmem_alloc_top_down+0x60/0x14c) sp:000000000002bdc8 [<0000000000013756>] _pa+0x56/0x6a sp:000000000002bdf0 [<0000000000013bcc>] pgtable_populate+0x45c/0x65e sp:000000000002be90 [<00000000000140aa>] setup_vmem+0x2da/0x424 sp:000000000002bec8 [<0000000000011c20>] startup_kernel+0x428/0x8b4 sp:000000000002bf60 [<00000000000100f4>] startup_normal+0xd4/0xd4 physmem_alloc_range allows to find free memory in specified range. It should be used for one time allocations only like finding position for amode31 and vmlinux. physmem_alloc_top_down can be used just like physmem_alloc_range, but it also allows multiple allocations per type and tries to merge sequential allocations together. Which is useful for paging structures allocations. If sequential allocations cannot be merged together they are "chained", allowing easy per type reserved ranges enumeration and migration to memblock later. Extra "struct reserved_range" allocated for chaining are not tracked or reserved but rely on the fact that both physmem_alloc_range and physmem_alloc_top_down search for free memory only below current top down allocator position. All reserved ranges should be transferred to memblock before memblock allocations are enabled. The startup code has been reordered to delay any memory allocations until online memory ranges are detected and occupied memory ranges are marked as reserved to be excluded from follow-up allocations. Ipl report certificates are a special case, ipl report certificates list is checked together with other memory reserves until certificates are saved elsewhere. KASAN required memory for shadow memory allocation and mapping is reserved as 1 large chunk which is later passed to KASAN early initialization code. Acked-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens