diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 05f8eefa3dcf..bbe4df6c2f8b 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -5,6 +5,7 @@ #include <asm/sections.h> #include <asm/cpu_mf.h> #include <asm/setup.h> +#include <asm/kasan.h> #include <asm/kexec.h> #include <asm/sclp.h> #include <asm/diag.h> @@ -15,8 +16,17 @@ extern char __boot_data_start[], __boot_data_end[]; extern char __boot_data_preserved_start[], __boot_data_preserved_end[]; unsigned long __bootdata_preserved(__kaslr_offset); +unsigned long __bootdata_preserved(VMALLOC_START); +unsigned long __bootdata_preserved(VMALLOC_END); +struct page *__bootdata_preserved(vmemmap); +unsigned long __bootdata_preserved(vmemmap_size); +unsigned long __bootdata_preserved(MODULES_VADDR); +unsigned long __bootdata_preserved(MODULES_END); unsigned long __bootdata(ident_map_size); +u64 __bootdata_preserved(stfle_fac_list[16]); +u64 __bootdata_preserved(alt_stfle_fac_list[16]); + /* * Some code and data needs to stay below 2 GB, even when the kernel would be * relocated above 2 GB, because it has to use 31 bit addresses. @@ -169,6 +179,86 @@ static void setup_ident_map_size(unsigned long max_physmem_end) #endif } +static void setup_kernel_memory_layout(void) +{ + bool vmalloc_size_verified = false; + unsigned long vmemmap_off; + unsigned long vspace_left; + unsigned long rte_size; + unsigned long pages; + unsigned long vmax; + + pages = ident_map_size / PAGE_SIZE; + /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */ + vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page); + + /* choose kernel address space layout: 4 or 3 levels. */ + vmemmap_off = round_up(ident_map_size, _REGION3_SIZE); + if (IS_ENABLED(CONFIG_KASAN) || + vmalloc_size > _REGION2_SIZE || + vmemmap_off + vmemmap_size + vmalloc_size + MODULES_LEN > _REGION2_SIZE) + vmax = _REGION1_SIZE; + else + vmax = _REGION2_SIZE; + + /* keep vmemmap_off aligned to a top level region table entry */ + rte_size = vmax == _REGION1_SIZE ? _REGION2_SIZE : _REGION3_SIZE; + MODULES_END = vmax; + if (is_prot_virt_host()) { + /* + * forcing modules and vmalloc area under the ultravisor + * secure storage limit, so that any vmalloc allocation + * we do could be used to back secure guest storage. + */ + adjust_to_uv_max(&MODULES_END); + } + +#ifdef CONFIG_KASAN + if (MODULES_END < vmax) { + /* force vmalloc and modules below kasan shadow */ + MODULES_END = min(MODULES_END, KASAN_SHADOW_START); + } else { + /* + * leave vmalloc and modules above kasan shadow but make + * sure they don't overlap with it + */ + vmalloc_size = min(vmalloc_size, vmax - KASAN_SHADOW_END - MODULES_LEN); + vmalloc_size_verified = true; + vspace_left = KASAN_SHADOW_START; + } +#endif + MODULES_VADDR = MODULES_END - MODULES_LEN; + VMALLOC_END = MODULES_VADDR; + + if (vmalloc_size_verified) { + VMALLOC_START = VMALLOC_END - vmalloc_size; + } else { + vmemmap_off = round_up(ident_map_size, rte_size); + + if (vmemmap_off + vmemmap_size > VMALLOC_END || + vmalloc_size > VMALLOC_END - vmemmap_off - vmemmap_size) { + /* + * allow vmalloc area to occupy up to 1/2 of + * the rest virtual space left. + */ + vmalloc_size = min(vmalloc_size, VMALLOC_END / 2); + } + VMALLOC_START = VMALLOC_END - vmalloc_size; + vspace_left = VMALLOC_START; + } + + pages = vspace_left / (PAGE_SIZE + sizeof(struct page)); + pages = SECTION_ALIGN_UP(pages); + vmemmap_off = round_up(vspace_left - pages * sizeof(struct page), rte_size); + /* keep vmemmap left most starting from a fresh region table entry */ + vmemmap_off = min(vmemmap_off, round_up(ident_map_size, rte_size)); + /* take care that identity map is lower then vmemmap */ + ident_map_size = min(ident_map_size, vmemmap_off); + vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page); + VMALLOC_START = max(vmemmap_off + vmemmap_size, VMALLOC_START); + vmemmap = (struct page *)vmemmap_off; +} + /* * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's. */ @@ -208,6 +298,7 @@ void startup_kernel(void) parse_boot_command_line(); setup_ident_map_size(detect_memory()); setup_vmalloc_size(); + setup_kernel_memory_layout(); random_lma = __kaslr_offset = 0; if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) { |