From 030b3ffbdac75005ef73af752a42cd48c7bba155 Mon Sep 17 00:00:00 2001 From: Sam Edwards Date: Wed, 3 Sep 2025 17:52:07 -0700 Subject: arm64: mm: Cast start/end markers to char *, not u64 There are a few memset() calls in map_kernel.c that cast marker-symbol addresses to u64 in order to perform pointer subtraction (range size computation). Cast them with (char *) instead, aligning with idiomatic C pointer arithmetic. This patch provably has no effect at runtime: I have verified that .text of vmlinux is identical after this change. Signed-off-by: Sam Edwards Signed-off-by: Will Deacon --- arch/arm64/kernel/pi/map_kernel.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index 0f4bd7771859..2b3047860230 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -179,7 +179,7 @@ static void __init remap_idmap_for_lpa2(void) * Don't bother with the FDT, we no longer need it after this. */ memset(init_idmap_pg_dir, 0, - (u64)init_idmap_pg_end - (u64)init_idmap_pg_dir); + (char *)init_idmap_pg_end - (char *)init_idmap_pg_dir); create_init_idmap(init_idmap_pg_dir, mask); dsb(ishst); @@ -188,7 +188,7 @@ static void __init remap_idmap_for_lpa2(void) set_ttbr0_for_lpa2((u64)init_idmap_pg_dir); /* wipe the temporary ID map from memory */ - memset(init_pg_dir, 0, (u64)init_pg_end - (u64)init_pg_dir); + memset(init_pg_dir, 0, (char *)init_pg_end - (char *)init_pg_dir); } static void __init map_fdt(u64 fdt) @@ -242,7 +242,7 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) map_fdt((u64)fdt); /* Clear BSS and the initial page tables */ - memset(__bss_start, 0, (u64)init_pg_end - (u64)__bss_start); + memset(__bss_start, 0, (char *)init_pg_end - (char *)__bss_start); /* Parse the command line for CPU feature overrides */ chosen = fdt_path_offset(fdt, chosen_str); -- cgit v1.2.3 From c56aa9a67a0853ffcf64ebe7f1dbe5a5a7c315cc Mon Sep 17 00:00:00 2001 From: Sam Edwards Date: Wed, 3 Sep 2025 17:52:08 -0700 Subject: arm64: mm: Make map_fdt() return mapped pointer Currently map_fdt() accepts a physical address and relies on the caller to keep using the same value after mapping, since the implementation happens to install an identity mapping. This obscures the fact that the usable pointer is defined by the mapping, not by the input value. Since the mapping determines pointer validity, it is more natural to produce the pointer at mapping time. Change map_fdt() to return a void * pointing to the mapped FDT. This clarifies the data flow, removes the implicit identity assumption, and prepares for making map_fdt() accept a phys_addr_t in a follow-up change. Signed-off-by: Sam Edwards Signed-off-by: Will Deacon --- arch/arm64/kernel/pi/map_kernel.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index 2b3047860230..5dc4107b5a7f 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -191,7 +191,7 @@ static void __init remap_idmap_for_lpa2(void) memset(init_pg_dir, 0, (char *)init_pg_end - (char *)init_pg_dir); } -static void __init map_fdt(u64 fdt) +static void *__init map_fdt(u64 fdt) { static u8 ptes[INIT_IDMAP_FDT_SIZE] __initdata __aligned(PAGE_SIZE); u64 efdt = fdt + MAX_FDT_SIZE; @@ -205,6 +205,8 @@ static void __init map_fdt(u64 fdt) fdt, PAGE_KERNEL, IDMAP_ROOT_LEVEL, (pte_t *)init_idmap_pg_dir, false, 0); dsb(ishst); + + return (void *)fdt; } /* @@ -238,15 +240,14 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) int root_level = 4 - CONFIG_PGTABLE_LEVELS; int va_bits = VA_BITS; int chosen; - - map_fdt((u64)fdt); + void *fdt_mapped = map_fdt((u64)fdt); /* Clear BSS and the initial page tables */ memset(__bss_start, 0, (char *)init_pg_end - (char *)__bss_start); /* Parse the command line for CPU feature overrides */ - chosen = fdt_path_offset(fdt, chosen_str); - init_feature_override(boot_status, fdt, chosen); + chosen = fdt_path_offset(fdt_mapped, chosen_str); + init_feature_override(boot_status, fdt_mapped, chosen); if (IS_ENABLED(CONFIG_ARM64_64K_PAGES) && !cpu_has_lva()) { va_bits = VA_BITS_MIN; @@ -266,7 +267,7 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) * fill in the high bits from the seed. */ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { - u64 kaslr_seed = kaslr_early_init(fdt, chosen); + u64 kaslr_seed = kaslr_early_init(fdt_mapped, chosen); if (kaslr_seed && kaslr_requires_kpti()) arm64_use_ng_mappings = ng_mappings_allowed(); -- cgit v1.2.3 From b868fff5b10b6d09506e93e489ee19166bf6c5d2 Mon Sep 17 00:00:00 2001 From: Sam Edwards Date: Wed, 3 Sep 2025 17:52:09 -0700 Subject: arm64: mm: Represent physical memory with phys_addr_t and resource_size_t This is a type-correctness cleanup to MMU/boot code that replaces several instances of void * and u64 with phys_addr_t (to represent addresses) and resource_size_t (to represent sizes) to emphasize that the code in question concerns physical memory specifically. The rationale for this change is to improve clarity and readability in a few modules that handle both types (physical and virtual) of address and differentiation is essential. I have left u64 in cases where the address may be either physical or virtual, where the address is exclusively virtual but used in heavy pointer arithmetic, and in cases I may have overlooked. I do not necessarily consider u64 the ideal type in those situations, but it avoids breaking existing semantics in this cleanup. This patch provably has no effect at runtime: I have verified that .text of vmlinux is identical after this change. Signed-off-by: Sam Edwards Signed-off-by: Will Deacon --- arch/arm64/kernel/pi/map_kernel.c | 26 +++++++++++++------------- arch/arm64/kernel/pi/map_range.c | 20 ++++++++++++-------- arch/arm64/kernel/pi/pi.h | 9 +++++---- 3 files changed, 30 insertions(+), 25 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index 5dc4107b5a7f..e6d35eff1486 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -18,9 +18,9 @@ extern const u8 __eh_frame_start[], __eh_frame_end[]; -extern void idmap_cpu_replace_ttbr1(void *pgdir); +extern void idmap_cpu_replace_ttbr1(phys_addr_t pgdir); -static void __init map_segment(pgd_t *pg_dir, u64 *pgd, u64 va_offset, +static void __init map_segment(pgd_t *pg_dir, phys_addr_t *pgd, u64 va_offset, void *start, void *end, pgprot_t prot, bool may_use_cont, int root_level) { @@ -40,7 +40,7 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) { bool enable_scs = IS_ENABLED(CONFIG_UNWIND_PATCH_PAC_INTO_SCS); bool twopass = IS_ENABLED(CONFIG_RELOCATABLE); - u64 pgdp = (u64)init_pg_dir + PAGE_SIZE; + phys_addr_t pgdp = (phys_addr_t)init_pg_dir + PAGE_SIZE; pgprot_t text_prot = PAGE_KERNEL_ROX; pgprot_t data_prot = PAGE_KERNEL; pgprot_t prot; @@ -90,7 +90,7 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) true, root_level); dsb(ishst); - idmap_cpu_replace_ttbr1(init_pg_dir); + idmap_cpu_replace_ttbr1((phys_addr_t)init_pg_dir); if (twopass) { if (IS_ENABLED(CONFIG_RELOCATABLE)) @@ -129,10 +129,10 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) /* Copy the root page table to its final location */ memcpy((void *)swapper_pg_dir + va_offset, init_pg_dir, PAGE_SIZE); dsb(ishst); - idmap_cpu_replace_ttbr1(swapper_pg_dir); + idmap_cpu_replace_ttbr1((phys_addr_t)swapper_pg_dir); } -static void noinline __section(".idmap.text") set_ttbr0_for_lpa2(u64 ttbr) +static void noinline __section(".idmap.text") set_ttbr0_for_lpa2(phys_addr_t ttbr) { u64 sctlr = read_sysreg(sctlr_el1); u64 tcr = read_sysreg(tcr_el1) | TCR_DS; @@ -172,7 +172,7 @@ static void __init remap_idmap_for_lpa2(void) */ create_init_idmap(init_pg_dir, mask); dsb(ishst); - set_ttbr0_for_lpa2((u64)init_pg_dir); + set_ttbr0_for_lpa2((phys_addr_t)init_pg_dir); /* * Recreate the initial ID map with the same granularity as before. @@ -185,17 +185,17 @@ static void __init remap_idmap_for_lpa2(void) dsb(ishst); /* switch back to the updated initial ID map */ - set_ttbr0_for_lpa2((u64)init_idmap_pg_dir); + set_ttbr0_for_lpa2((phys_addr_t)init_idmap_pg_dir); /* wipe the temporary ID map from memory */ memset(init_pg_dir, 0, (char *)init_pg_end - (char *)init_pg_dir); } -static void *__init map_fdt(u64 fdt) +static void *__init map_fdt(phys_addr_t fdt) { static u8 ptes[INIT_IDMAP_FDT_SIZE] __initdata __aligned(PAGE_SIZE); - u64 efdt = fdt + MAX_FDT_SIZE; - u64 ptep = (u64)ptes; + phys_addr_t efdt = fdt + MAX_FDT_SIZE; + phys_addr_t ptep = (phys_addr_t)ptes; /* We're idmapped when called */ /* * Map up to MAX_FDT_SIZE bytes, but avoid overlap with @@ -232,7 +232,7 @@ static bool __init ng_mappings_allowed(void) return true; } -asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) +asmlinkage void __init early_map_kernel(u64 boot_status, phys_addr_t fdt) { static char const chosen_str[] __initconst = "/chosen"; u64 va_base, pa_base = (u64)&_text; @@ -240,7 +240,7 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) int root_level = 4 - CONFIG_PGTABLE_LEVELS; int va_bits = VA_BITS; int chosen; - void *fdt_mapped = map_fdt((u64)fdt); + void *fdt_mapped = map_fdt(fdt); /* Clear BSS and the initial page tables */ memset(__bss_start, 0, (char *)init_pg_end - (char *)__bss_start); diff --git a/arch/arm64/kernel/pi/map_range.c b/arch/arm64/kernel/pi/map_range.c index 7982788e7b9a..de52cd85c691 100644 --- a/arch/arm64/kernel/pi/map_range.c +++ b/arch/arm64/kernel/pi/map_range.c @@ -26,8 +26,9 @@ * @va_offset: Offset between a physical page and its current mapping * in the VA space */ -void __init map_range(u64 *pte, u64 start, u64 end, u64 pa, pgprot_t prot, - int level, pte_t *tbl, bool may_use_cont, u64 va_offset) +void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa, + pgprot_t prot, int level, pte_t *tbl, bool may_use_cont, + u64 va_offset) { u64 cmask = (level == 3) ? CONT_PTE_SIZE - 1 : U64_MAX; ptdesc_t protval = pgprot_val(prot) & ~PTE_TYPE_MASK; @@ -87,19 +88,22 @@ void __init map_range(u64 *pte, u64 start, u64 end, u64 pa, pgprot_t prot, } } -asmlinkage u64 __init create_init_idmap(pgd_t *pg_dir, ptdesc_t clrmask) +asmlinkage phys_addr_t __init create_init_idmap(pgd_t *pg_dir, ptdesc_t clrmask) { - u64 ptep = (u64)pg_dir + PAGE_SIZE; + phys_addr_t ptep = (phys_addr_t)pg_dir + PAGE_SIZE; /* MMU is off */ pgprot_t text_prot = PAGE_KERNEL_ROX; pgprot_t data_prot = PAGE_KERNEL; pgprot_val(text_prot) &= ~clrmask; pgprot_val(data_prot) &= ~clrmask; - map_range(&ptep, (u64)_stext, (u64)__initdata_begin, (u64)_stext, - text_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0); - map_range(&ptep, (u64)__initdata_begin, (u64)_end, (u64)__initdata_begin, - data_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0); + /* MMU is off; pointer casts to phys_addr_t are safe */ + map_range(&ptep, (u64)_stext, (u64)__initdata_begin, + (phys_addr_t)_stext, text_prot, IDMAP_ROOT_LEVEL, + (pte_t *)pg_dir, false, 0); + map_range(&ptep, (u64)__initdata_begin, (u64)_end, + (phys_addr_t)__initdata_begin, data_prot, IDMAP_ROOT_LEVEL, + (pte_t *)pg_dir, false, 0); return ptep; } diff --git a/arch/arm64/kernel/pi/pi.h b/arch/arm64/kernel/pi/pi.h index 46cafee7829f..08ef9f80456b 100644 --- a/arch/arm64/kernel/pi/pi.h +++ b/arch/arm64/kernel/pi/pi.h @@ -29,9 +29,10 @@ u64 kaslr_early_init(void *fdt, int chosen); void relocate_kernel(u64 offset); int scs_patch(const u8 eh_frame[], int size); -void map_range(u64 *pgd, u64 start, u64 end, u64 pa, pgprot_t prot, - int level, pte_t *tbl, bool may_use_cont, u64 va_offset); +void map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa, + pgprot_t prot, int level, pte_t *tbl, bool may_use_cont, + u64 va_offset); -asmlinkage void early_map_kernel(u64 boot_status, void *fdt); +asmlinkage void early_map_kernel(u64 boot_status, phys_addr_t fdt); -asmlinkage u64 create_init_idmap(pgd_t *pgd, ptdesc_t clrmask); +asmlinkage phys_addr_t create_init_idmap(pgd_t *pgd, ptdesc_t clrmask); -- cgit v1.2.3 From a166563e7ec375b38a0fd3a58f7b77e50a6bc6a8 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Wed, 17 Sep 2025 12:02:09 -0700 Subject: arm64: mm: support large block mapping when rodata=full When rodata=full is specified, kernel linear mapping has to be mapped at PTE level since large page table can't be split due to break-before-make rule on ARM64. This resulted in a couple of problems: - performance degradation - more TLB pressure - memory waste for kernel page table With FEAT_BBM level 2 support, splitting large block page table to smaller ones doesn't need to make the page table entry invalid anymore. This allows kernel split large block mapping on the fly. Add kernel page table split support and use large block mapping by default when FEAT_BBM level 2 is supported for rodata=full. When changing permissions for kernel linear mapping, the page table will be split to smaller size. The machine without FEAT_BBM level 2 will fallback to have kernel linear mapping PTE-mapped when rodata=full. With this we saw significant performance boost with some benchmarks and much less memory consumption on my AmpereOne machine (192 cores, 1P) with 256GB memory. * Memory use after boot Before: MemTotal: 258988984 kB MemFree: 254821700 kB After: MemTotal: 259505132 kB MemFree: 255410264 kB Around 500MB more memory are free to use. The larger the machine, the more memory saved. * Memcached We saw performance degradation when running Memcached benchmark with rodata=full vs rodata=on. Our profiling pointed to kernel TLB pressure. With this patchset we saw ops/sec is increased by around 3.5%, P99 latency is reduced by around 9.6%. The gain mainly came from reduced kernel TLB misses. The kernel TLB MPKI is reduced by 28.5%. The benchmark data is now on par with rodata=on too. * Disk encryption (dm-crypt) benchmark Ran fio benchmark with the below command on a 128G ramdisk (ext4) with disk encryption (by dm-crypt). fio --directory=/data --random_generator=lfsr --norandommap \ --randrepeat 1 --status-interval=999 --rw=write --bs=4k --loops=1 \ --ioengine=sync --iodepth=1 --numjobs=1 --fsync_on_close=1 \ --group_reporting --thread --name=iops-test-job --eta-newline=1 \ --size 100G The IOPS is increased by 90% - 150% (the variance is high, but the worst number of good case is around 90% more than the best number of bad case). The bandwidth is increased and the avg clat is reduced proportionally. * Sequential file read Read 100G file sequentially on XFS (xfs_io read with page cache populated). The bandwidth is increased by 150%. Co-developed-by: Ryan Roberts Signed-off-by: Ryan Roberts Reviewed-by: Catalin Marinas Signed-off-by: Yang Shi Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 9ad065f15f1d..e15472beff3f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2217,7 +2217,7 @@ static bool hvhe_possible(const struct arm64_cpu_capabilities *entry, return arm64_test_sw_feature_override(ARM64_SW_FEATURE_OVERRIDE_HVHE); } -static bool has_bbml2_noabort(const struct arm64_cpu_capabilities *caps, int scope) +bool cpu_supports_bbml2_noabort(void) { /* * We want to allow usage of BBML2 in as wide a range of kernel contexts @@ -2249,6 +2249,11 @@ static bool has_bbml2_noabort(const struct arm64_cpu_capabilities *caps, int sco return true; } +static bool has_bbml2_noabort(const struct arm64_cpu_capabilities *caps, int scope) +{ + return cpu_supports_bbml2_noabort(); +} + #ifdef CONFIG_ARM64_PAN static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused) { -- cgit v1.2.3 From 3df6979d222b8638a60aa6921b73cb5f3e4f5dcb Mon Sep 17 00:00:00 2001 From: Ryan Roberts Date: Wed, 17 Sep 2025 12:02:10 -0700 Subject: arm64: mm: split linear mapping if BBML2 unsupported on secondary CPUs The kernel linear mapping is painted in very early stage of system boot. The cpufeature has not been finalized yet at this point. So the linear mapping is determined by the capability of boot CPU only. If the boot CPU supports BBML2, large block mappings will be used for linear mapping. But the secondary CPUs may not support BBML2, so repaint the linear mapping if large block mapping is used and the secondary CPUs don't support BBML2 once cpufeature is finalized on all CPUs. If the boot CPU doesn't support BBML2 or the secondary CPUs have the same BBML2 capability with the boot CPU, repainting the linear mapping is not needed. Repainting is implemented by the boot CPU, which we know supports BBML2, so it is safe for the live mapping size to change for this CPU. The linear map region is walked using the pagewalk API and any discovered large leaf mappings are split to pte mappings using the existing helper functions. Since the repainting is performed inside of a stop_machine(), we must use GFP_ATOMIC to allocate the extra intermediate pgtables. But since we are still early in boot, it is expected that there is plenty of memory available so we will never need to sleep for reclaim, and so GFP_ATOMIC is acceptable here. The secondary CPUs are all put into a waiting area with the idmap in TTBR0 and reserved map in TTBR1 while this is performed since they cannot be allowed to observe any size changes on the live mappings. Some of this infrastructure is reused from the kpti case. Specifically we share the same flag (was __idmap_kpti_flag, now idmap_kpti_bbml2_flag) since it means we don't have to reserve any extra pgtable memory to idmap the extra flag. Co-developed-by: Yang Shi Signed-off-by: Yang Shi Signed-off-by: Ryan Roberts Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e15472beff3f..3780f343fd2c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -85,6 +85,7 @@ #include #include #include +#include #include #include #include @@ -2027,6 +2028,7 @@ static void __init kpti_install_ng_mappings(void) if (arm64_use_ng_mappings) return; + init_idmap_kpti_bbml2_flag(); stop_machine(__kpti_install_ng_mappings, NULL, cpu_online_mask); } @@ -3928,6 +3930,7 @@ void __init setup_system_features(void) { setup_system_capabilities(); + linear_map_maybe_split_to_ptes(); kpti_install_ng_mappings(); sve_setup(); -- cgit v1.2.3 From 5973a62efa34c80c9a4e5eac1fca6f6209b902af Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Fri, 19 Sep 2025 14:27:51 -0700 Subject: arm64: map [_text, _stext) virtual address range non-executable+read-only Since the referenced fixes commit, the kernel's .text section is only mapped starting from _stext; the region [_text, _stext) is omitted. As a result, other vmalloc/vmap allocations may use the virtual addresses nominally in the range [_text, _stext). This address reuse confuses multiple things: 1. crash_prepare_elf64_headers() sets up a segment in /proc/vmcore mapping the entire range [_text, _end) to [__pa_symbol(_text), __pa_symbol(_end)). Reading an address in [_text, _stext) from /proc/vmcore therefore gives the incorrect result. 2. Tools doing symbolization (either by reading /proc/kallsyms or based on the vmlinux ELF file) will incorrectly identify vmalloc/vmap allocations in [_text, _stext) as kernel symbols. In practice, both of these issues affect the drgn debugger. Specifically, there were cases where the vmap IRQ stacks for some CPUs were allocated in [_text, _stext). As a result, drgn could not get the stack trace for a crash in an IRQ handler because the core dump contained invalid data for the IRQ stack address. The stack addresses were also symbolized as being in the _text symbol. Fix this by bringing back the mapping of [_text, _stext), but now make it non-executable and read-only. This prevents other allocations from using it while still achieving the original goal of not mapping unpredictable data as executable. Other than the changed protection, this is effectively a revert of the fixes commit. Fixes: e2a073dde921 ("arm64: omit [_text, _stext) from permanent kernel mapping") Cc: stable@vger.kernel.org Signed-off-by: Omar Sandoval Signed-off-by: Will Deacon --- arch/arm64/kernel/pi/map_kernel.c | 6 ++++++ arch/arm64/kernel/setup.c | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index e6d35eff1486..e8ddbde31a83 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -78,6 +78,12 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) twopass |= enable_scs; prot = twopass ? data_prot : text_prot; + /* + * [_stext, _text) isn't executed after boot and contains some + * non-executable, unpredictable data, so map it non-executable. + */ + map_segment(init_pg_dir, &pgdp, va_offset, _text, _stext, data_prot, + false, root_level); map_segment(init_pg_dir, &pgdp, va_offset, _stext, _etext, prot, !twopass, root_level); map_segment(init_pg_dir, &pgdp, va_offset, __start_rodata, diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 77c7926a4df6..23c05dc7a8f2 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -214,7 +214,7 @@ static void __init request_standard_resources(void) unsigned long i = 0; size_t res_size; - kernel_code.start = __pa_symbol(_stext); + kernel_code.start = __pa_symbol(_text); kernel_code.end = __pa_symbol(__init_begin - 1); kernel_data.start = __pa_symbol(_sdata); kernel_data.end = __pa_symbol(_end - 1); @@ -280,7 +280,7 @@ u64 cpu_logical_map(unsigned int cpu) void __init __no_sanitize_address setup_arch(char **cmdline_p) { - setup_initial_init_mm(_stext, _etext, _edata, _end); + setup_initial_init_mm(_text, _etext, _edata, _end); *cmdline_p = boot_command_line; -- cgit v1.2.3