From: Vasily Gorbik Date: Wed, 11 Dec 2024 15:57:21 +0000 (+0100) Subject: s390/boot: Add startup debugging support X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ec6f9f7e5bbf983323d53b66e8a76d699d26736c;p=users%2Fdwmw2%2Flinux.git s390/boot: Add startup debugging support Add boot_debug() calls to log various memory layout decisions and randomization details during early startup, improving debugging capabilities. Signed-off-by: Vasily Gorbik Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 89f1d12f1c100..807594cf246c1 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 +#define boot_fmt(fmt) "startup: " fmt #include #include #include @@ -223,12 +224,16 @@ static void setup_ident_map_size(unsigned long max_physmem_end) if (oldmem_data.start) { __kaslr_enabled = 0; ident_map_size = min(ident_map_size, oldmem_data.size); + boot_debug("kdump memory limit: 0x%016lx\n", oldmem_data.size); } else if (ipl_block_valid && is_ipl_block_dump()) { __kaslr_enabled = 0; - if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size) + if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size) { ident_map_size = min(ident_map_size, hsa_size); + boot_debug("Stand-alone dump limit: 0x%016lx\n", hsa_size); + } } #endif + boot_debug("Identity map size: 0x%016lx\n", ident_map_size); } #define FIXMAP_SIZE round_up(MEMCPY_REAL_SIZE + ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore)) @@ -266,6 +271,7 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) BUILD_BUG_ON(!IS_ALIGNED(__NO_KASLR_START_KERNEL, THREAD_SIZE)); BUILD_BUG_ON(__NO_KASLR_END_KERNEL > _REGION1_SIZE); vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION3_SIZE); + boot_debug("vmem size estimated: 0x%016lx\n", vsize); if (IS_ENABLED(CONFIG_KASAN) || __NO_KASLR_END_KERNEL > _REGION2_SIZE || (vsize > _REGION2_SIZE && kaslr_enabled())) { asce_limit = _REGION1_SIZE; @@ -289,8 +295,10 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) * otherwise asce_limit and rte_size would have been adjusted. */ vmax = adjust_to_uv_max(asce_limit); + boot_debug("%d level paging 0x%016lx vmax\n", vmax == _REGION1_SIZE ? 4 : 3, vmax); #ifdef CONFIG_KASAN BUILD_BUG_ON(__NO_KASLR_END_KERNEL > KASAN_SHADOW_START); + boot_debug("KASAN shadow area: 0x%016lx-0x%016lx\n", KASAN_SHADOW_START, KASAN_SHADOW_END); /* force vmalloc and modules below kasan shadow */ vmax = min(vmax, KASAN_SHADOW_START); #endif @@ -304,19 +312,27 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) pos = 0; kernel_end = vmax - pos * THREAD_SIZE; kernel_start = round_down(kernel_end - kernel_size, THREAD_SIZE); + boot_debug("Randomization range: 0x%016lx-0x%016lx\n", vmax - kaslr_len, vmax); + boot_debug("kernel image: 0x%016lx-0x%016lx (kaslr)\n", kernel_start, + kernel_size + kernel_size); } else if (vmax < __NO_KASLR_END_KERNEL || vsize > __NO_KASLR_END_KERNEL) { kernel_start = round_down(vmax - kernel_size, THREAD_SIZE); - boot_debug("The kernel base address is forced to %lx\n", kernel_start); + boot_debug("kernel image: 0x%016lx-0x%016lx (constrained)\n", kernel_start, + kernel_start + kernel_size); } else { kernel_start = __NO_KASLR_START_KERNEL; + boot_debug("kernel image: 0x%016lx-0x%016lx (nokaslr)\n", kernel_start, + kernel_start + kernel_size); } __kaslr_offset = kernel_start; + boot_debug("__kaslr_offset: 0x%016lx\n", __kaslr_offset); MODULES_END = round_down(kernel_start, _SEGMENT_SIZE); MODULES_VADDR = MODULES_END - MODULES_LEN; VMALLOC_END = MODULES_VADDR; if (IS_ENABLED(CONFIG_KMSAN)) VMALLOC_END -= MODULES_LEN * 2; + boot_debug("modules area: 0x%016lx-0x%016lx\n", MODULES_VADDR, MODULES_END); /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */ vsize = (VMALLOC_END - FIXMAP_SIZE) / 2; @@ -328,10 +344,15 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) VMALLOC_END -= vmalloc_size * 2; } VMALLOC_START = VMALLOC_END - vmalloc_size; + boot_debug("vmalloc area: 0x%016lx-0x%016lx\n", VMALLOC_START, VMALLOC_END); __memcpy_real_area = round_down(VMALLOC_START - MEMCPY_REAL_SIZE, PAGE_SIZE); + boot_debug("memcpy real area: 0x%016lx-0x%016lx\n", __memcpy_real_area, + __memcpy_real_area + MEMCPY_REAL_SIZE); __abs_lowcore = round_down(__memcpy_real_area - ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore)); + boot_debug("abs lowcore: 0x%016lx-0x%016lx\n", __abs_lowcore, + __abs_lowcore + ABS_LOWCORE_MAP_SIZE); /* split remaining virtual space between 1:1 mapping & vmemmap array */ pages = __abs_lowcore / (PAGE_SIZE + sizeof(struct page)); @@ -353,6 +374,8 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) max_mappable = min(max_mappable, vmemmap_start); if (IS_ENABLED(CONFIG_RANDOMIZE_IDENTITY_BASE)) __identity_base = round_down(vmemmap_start - max_mappable, rte_size); + boot_debug("identity map: 0x%016lx-0x%016lx\n", __identity_base, + __identity_base + ident_map_size); return asce_limit; } @@ -542,5 +565,6 @@ void startup_kernel(void) */ psw.addr = __kaslr_offset + vmlinux.entry; psw.mask = PSW_KERNEL_BITS; + boot_debug("Starting kernel at: 0x%016lx\n", psw.addr); __load_psw(psw); }