From 18210a104bb97e28c26dc31fd9fc7b5c381fec62 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Mon, 17 Aug 2026 22:07:14 +0800 Subject: [PATCH] LoongArch: Expand module virtual address space to 2GB The current 256MB module virtual address space is easily exhausted when loading massive graphics drivers such as amdgpu along with the large unstripped symbol tables, resulting in allocation failures of "execmem: unable to allocate memory". Thus, expand the module virtual address space to 2GB while keeping the current normal code model '-mcmodel=normal', rather than using the medium code model '-mcmodel=medium'. This approach avoids the extra performance overhead and larger binary size of forcing every function call into a 2-instruction sequence of 'pcaddu18i + jirl'. Given that individual module code segments rarely exceed 128MB, most jumps remain fast direct calls by using the bl instruction. For the long-distance jumps exceeding the +/-128MB limit, apply_r_larch_b26() emits PLT entries, while signed_imm_check() guarantees the run-time safety by rejecting any out-of-bound instruction offsets. There is still a risk that the distance between .init.text and .text of the same module exceeds 128MB. So we divide the 2GB virtual space to be two sub-regions: the first 256MB is for module text, and the rest is for module data. Cc: stable@vger.kernel.org Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen --- arch/loongarch/include/asm/pgtable.h | 2 +- arch/loongarch/mm/init.c | 17 ++++++++++++++--- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index 59b37a824bab..a2191044435d 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -96,7 +96,7 @@ struct vm_area_struct; #ifdef CONFIG_64BIT #define MODULES_VADDR (vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE)) -#define MODULES_END (MODULES_VADDR + SZ_256M) +#define MODULES_END (MODULES_VADDR + SZ_2G) /* 256MB for text, rest for data */ #ifdef CONFIG_KFENCE #define KFENCE_AREA_SIZE (((CONFIG_KFENCE_NUM_OBJECTS + 1) * 2 + 2) * PAGE_SIZE) diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c index 3407030f3e7a..4b46c5d30708 100644 --- a/arch/loongarch/mm/init.c +++ b/arch/loongarch/mm/init.c @@ -237,15 +237,26 @@ pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; EXPORT_SYMBOL(invalid_pte_table); #if defined(CONFIG_EXECMEM) && defined(MODULES_VADDR) +#define MODULES_TEXT_START (MODULES_VADDR) +#define MODULES_TEXT_END (MODULES_VADDR + SZ_256M) +#define MODULES_DATA_START (MODULES_VADDR + SZ_256M) +#define MODULES_DATA_END (MODULES_END) + static struct execmem_info execmem_info __ro_after_init; struct execmem_info __init *execmem_arch_setup(void) { execmem_info = (struct execmem_info){ .ranges = { - [EXECMEM_DEFAULT] = { - .start = MODULES_VADDR, - .end = MODULES_END, + [EXECMEM_MODULE_TEXT] = { + .start = MODULES_TEXT_START, + .end = MODULES_TEXT_END, + .pgprot = PAGE_KERNEL, + .alignment = 1, + }, + [EXECMEM_MODULE_DATA] = { + .start = MODULES_DATA_START, + .end = MODULES_DATA_END, .pgprot = PAGE_KERNEL, .alignment = 1, },