From af0735269b72333d06e9677cb843bf5ce689a38c Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Fri, 10 Feb 2023 15:47:06 +0100 Subject: [PATCH] s390/mem_detect: do not truncate online memory ranges info Commit bf64f0517e5d ("s390/mem_detect: handle online memory limit just once") introduced truncation of mem_detect online ranges based on identity mapping size. For kdump case however the full set of online memory ranges has to be feed into memblock_physmem_add so that crashed system memory could be extracted. Instead of truncating introduce a "usable limit" which is respected by mem_detect api. Also add extra online memory ranges iterator which still provides full set of online memory ranges disregarding the "usable limit". Fixes: bf64f0517e5d ("s390/mem_detect: handle online memory limit just once") Reported-by: Alexander Egorenkov Tested-by: Alexander Egorenkov Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens --- arch/s390/boot/boot.h | 2 +- arch/s390/boot/kaslr.c | 10 +++++----- arch/s390/boot/mem_detect.c | 12 ++++++------ arch/s390/boot/startup.c | 2 +- arch/s390/boot/vmem.c | 2 +- arch/s390/include/asm/mem_detect.h | 32 ++++++++++++++++++++++---------- arch/s390/kernel/setup.c | 4 ++-- arch/s390/mm/kasan_init.c | 4 ++-- 8 files changed, 40 insertions(+), 28 deletions(-) diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h index ed85b14..58ce701d 100644 --- a/arch/s390/boot/boot.h +++ b/arch/s390/boot/boot.h @@ -34,7 +34,7 @@ struct vmlinux_info { void startup_kernel(void); unsigned long detect_memory(unsigned long *safe_addr); -void mem_detect_truncate(unsigned long limit); +void mem_detect_set_usable_limit(unsigned long limit); bool is_ipl_block_dump(void); void store_ipl_parmblock(void); unsigned long read_ipl_report(unsigned long safe_addr); diff --git a/arch/s390/boot/kaslr.c b/arch/s390/boot/kaslr.c index 70ff68d..3e3d846 100644 --- a/arch/s390/boot/kaslr.c +++ b/arch/s390/boot/kaslr.c @@ -132,7 +132,7 @@ static unsigned long count_valid_kernel_positions(unsigned long kernel_size, unsigned long start, end, pos = 0; int i; - for_each_mem_detect_block(i, &start, &end) { + for_each_mem_detect_usable_block(i, &start, &end) { if (_min >= end) continue; if (start >= _max) @@ -153,7 +153,7 @@ static unsigned long position_to_address(unsigned long pos, unsigned long kernel unsigned long start, end; int i; - for_each_mem_detect_block(i, &start, &end) { + for_each_mem_detect_usable_block(i, &start, &end) { if (_min >= end) continue; if (start >= _max) @@ -172,7 +172,7 @@ static unsigned long position_to_address(unsigned long pos, unsigned long kernel unsigned long get_random_base(unsigned long safe_addr) { - unsigned long online_mem_total = get_mem_detect_online_total(); + unsigned long usable_total = get_mem_detect_usable_total(); unsigned long memory_limit = get_mem_detect_end(); unsigned long base_pos, max_pos, kernel_size; int i; @@ -182,8 +182,8 @@ unsigned long get_random_base(unsigned long safe_addr) * which vmem and kasan code will use for shadow memory and * pgtable mapping allocations. */ - memory_limit -= kasan_estimate_memory_needs(online_mem_total); - memory_limit -= vmem_estimate_memory_needs(online_mem_total); + memory_limit -= kasan_estimate_memory_needs(usable_total); + memory_limit -= vmem_estimate_memory_needs(usable_total); safe_addr = ALIGN(safe_addr, THREAD_SIZE); kernel_size = vmlinux.image_size + vmlinux.bss_size; diff --git a/arch/s390/boot/mem_detect.c b/arch/s390/boot/mem_detect.c index 3058d39..35f4ba1 100644 --- a/arch/s390/boot/mem_detect.c +++ b/arch/s390/boot/mem_detect.c @@ -172,20 +172,20 @@ unsigned long detect_memory(unsigned long *safe_addr) return max_physmem_end; } -void mem_detect_truncate(unsigned long limit) +void mem_detect_set_usable_limit(unsigned long limit) { struct mem_detect_block *block; int i; + /* make sure mem_detect.usable ends up within online memory block */ for (i = 0; i < mem_detect.count; i++) { block = __get_mem_detect_block_ptr(i); - if (block->start >= limit) { - mem_detect.count = i; + if (block->start >= limit) break; - } else if (block->end > limit) { - block->end = (u64)limit; - mem_detect.count = i + 1; + if (block->end >= limit) { + mem_detect.usable = limit; break; } + mem_detect.usable = block->end; } } diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index f5a7545..11413f0 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -304,7 +304,7 @@ void startup_kernel(void) setup_ident_map_size(max_physmem_end); setup_vmalloc_size(); asce_limit = setup_kernel_memory_layout(); - mem_detect_truncate(ident_map_size); + mem_detect_set_usable_limit(ident_map_size); if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) { random_lma = get_random_base(safe_addr); diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c index 4e54357..4d1d0d8 100644 --- a/arch/s390/boot/vmem.c +++ b/arch/s390/boot/vmem.c @@ -252,7 +252,7 @@ void setup_vmem(unsigned long asce_limit) */ pgtable_populate_init(); pgtable_populate(0, sizeof(struct lowcore), POPULATE_ONE2ONE); - for_each_mem_detect_block(i, &start, &end) + for_each_mem_detect_usable_block(i, &start, &end) pgtable_populate(start, end, POPULATE_ONE2ONE); pgtable_populate(__abs_lowcore, __abs_lowcore + sizeof(struct lowcore), POPULATE_ABS_LOWCORE); diff --git a/arch/s390/include/asm/mem_detect.h b/arch/s390/include/asm/mem_detect.h index decd8c4..f9e7354 100644 --- a/arch/s390/include/asm/mem_detect.h +++ b/arch/s390/include/asm/mem_detect.h @@ -30,6 +30,7 @@ struct mem_detect_block { struct mem_detect_info { u32 count; u8 info_source; + unsigned long usable; struct mem_detect_block entries[MEM_INLINED_ENTRIES]; struct mem_detect_block *entries_extended; }; @@ -38,7 +39,7 @@ extern struct mem_detect_info mem_detect; void add_mem_detect_block(u64 start, u64 end); static inline int __get_mem_detect_block(u32 n, unsigned long *start, - unsigned long *end) + unsigned long *end, bool respect_usable_limit) { if (n >= mem_detect.count) { *start = 0; @@ -53,28 +54,37 @@ static inline int __get_mem_detect_block(u32 n, unsigned long *start, *start = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].start; *end = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].end; } + + if (respect_usable_limit && mem_detect.usable) { + if (*start >= mem_detect.usable) + return -1; + if (*end > mem_detect.usable) + *end = mem_detect.usable; + } return 0; } /** - * for_each_mem_detect_block - early online memory range iterator + * for_each_mem_detect_usable_block - early online memory range iterator * @i: an integer used as loop variable * @p_start: ptr to unsigned long for start address of the range * @p_end: ptr to unsigned long for end address of the range * - * Walks over detected online memory ranges. + * Walks over detected online memory ranges below usable limit. */ -#define for_each_mem_detect_block(i, p_start, p_end) \ - for (i = 0, __get_mem_detect_block(i, p_start, p_end); \ - i < mem_detect.count; \ - i++, __get_mem_detect_block(i, p_start, p_end)) +#define for_each_mem_detect_usable_block(i, p_start, p_end) \ + for (i = 0; !__get_mem_detect_block(i, p_start, p_end, true); i++) + +/* Walks over all detected online memory ranges disregarding usable limit. */ +#define for_each_mem_detect_block(i, p_start, p_end) \ + for (i = 0; !__get_mem_detect_block(i, p_start, p_end, false); i++) -static inline unsigned long get_mem_detect_online_total(void) +static inline unsigned long get_mem_detect_usable_total(void) { unsigned long start, end, total = 0; int i; - for_each_mem_detect_block(i, &start, &end) + for_each_mem_detect_usable_block(i, &start, &end) total += end - start; return total; @@ -95,8 +105,10 @@ static inline unsigned long get_mem_detect_end(void) unsigned long start; unsigned long end; + if (mem_detect.usable) + return mem_detect.usable; if (mem_detect.count) { - __get_mem_detect_block(mem_detect.count - 1, &start, &end); + __get_mem_detect_block(mem_detect.count - 1, &start, &end, false); return end; } return 0; diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index d8f41cc..8ec5cdf 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -772,10 +772,10 @@ static void __init memblock_add_mem_detect_info(void) get_mem_info_source(), mem_detect.info_source); /* keep memblock lists close to the kernel */ memblock_set_bottom_up(true); - for_each_mem_detect_block(i, &start, &end) { + for_each_mem_detect_usable_block(i, &start, &end) memblock_add(start, end - start); + for_each_mem_detect_block(i, &start, &end) memblock_physmem_add(start, end - start); - } memblock_set_bottom_up(false); memblock_set_node(0, ULONG_MAX, &memblock.memory, 0); } diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c index 4f667828..ef89a5f 100644 --- a/arch/s390/mm/kasan_init.c +++ b/arch/s390/mm/kasan_init.c @@ -244,7 +244,7 @@ void __init kasan_early_init(void) memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE); if (has_edat) { - shadow_alloc_size = get_mem_detect_online_total() >> KASAN_SHADOW_SCALE_SHIFT; + shadow_alloc_size = get_mem_detect_usable_total() >> KASAN_SHADOW_SCALE_SHIFT; segment_pos = round_down(pgalloc_pos, _SEGMENT_SIZE); segment_low = segment_pos - shadow_alloc_size; segment_low = round_down(segment_low, _SEGMENT_SIZE); @@ -282,7 +282,7 @@ void __init kasan_early_init(void) * +- shadow end ----+---------+- shadow end ---+ */ /* populate kasan shadow (for identity mapping and zero page mapping) */ - for_each_mem_detect_block(i, &start, &end) + for_each_mem_detect_usable_block(i, &start, &end) kasan_early_pgtable_populate(__sha(start), __sha(end), POPULATE_MAP); if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { untracked_end = VMALLOC_START; -- 2.7.4