Unverified Commit 2cffc956 authored by Zong Li's avatar Zong Li Committed by Palmer Dabbelt
Browse files

RISC-V: Support MODULE_SECTIONS mechanism on RV32 



This patch supports dynamic generate got and plt sections mechanism on
rv32. It contains the modification as follows:
 - Always enable MODULE_SECTIONS (both rv64 and rv32)
 - Change the fixed size type.

This patch had been tested by following modules:

btrfs 6795991 0 - Live 0xa544b000
test_static_keys 17304 0 - Live 0xa28be000
zstd_compress 1198986 1 btrfs, Live 0xa2a25000
zstd_decompress 608112 1 btrfs, Live 0xa24e7000
lzo 8787 0 - Live 0xa2049000
xor 27461 1 btrfs, Live 0xa2041000
zram 78849 0 - Live 0xa2276000
netdevsim 55909 0 - Live 0xa202d000
tun 211534 0 - Live 0xa21b5000
fuse 566049 0 - Live 0xa25fb000
nfs_layout_flexfiles 192597 0 - Live 0xa229b000
ramoops 74895 0 - Live 0xa2019000
xfs 3973221 0 - Live 0xa507f000
libcrc32c 3053 2 btrfs,xfs, Live 0xa34af000
lzo_compress 17302 2 btrfs,lzo, Live 0xa347d000
lzo_decompress 7178 2 btrfs,lzo, Live 0xa3451000
raid6_pq 142086 1 btrfs, Live 0xa33a4000
reed_solomon 31022 1 ramoops, Live 0xa31eb000
test_bitmap 3734 0 - Live 0xa31af000
test_bpf 1588736 0 - Live 0xa2c11000
test_kmod 41161 0 - Live 0xa29f8000
test_module 1356 0 - Live 0xa299e000
test_printf 6024 0 [permanent], Live 0xa2971000
test_static_key_base 5797 1 test_static_keys, Live 0xa2931000
test_user_copy 4382 0 - Live 0xa28c9000
xxhash 70501 2 zstd_compress,zstd_decompress, Live 0xa2055000

Signed-off-by: default avatarZong Li <zong@andestech.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 3b56adcf

arch/riscv/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ config RISCV 
	select HAVE_ARCH_TRACEHOOK

	select HAVE_PCI

	select MODULES_USE_ELF_RELA if MODULES

	select MODULE_SECTIONS if MODULES

	select THREAD_INFO_IN_TASK

	select PCI_DOMAINS_GENERIC if PCI

	select PCI_MSI if PCI
@@ -152,7 +153,6 @@ choice 
		bool "2GiB"

	config MAXPHYSMEM_128GB

		depends on 64BIT && CMODEL_MEDANY

		select MODULE_SECTIONS if MODULES

		bool "128GiB"

endchoice

arch/riscv/include/asm/module.h

+15 −13
Original line number Diff line number Diff line
@@ -9,12 +9,12 @@ 
#define MODULE_ARCH_VERMAGIC    "riscv"



struct module;

u64 module_emit_got_entry(struct module *mod, u64 val);

u64 module_emit_plt_entry(struct module *mod, u64 val);

unsigned long module_emit_got_entry(struct module *mod, unsigned long val);

unsigned long module_emit_plt_entry(struct module *mod, unsigned long val);



#ifdef CONFIG_MODULE_SECTIONS

struct mod_section {

	struct elf64_shdr *shdr;

	Elf_Shdr *shdr;

	int num_entries;

	int max_entries;

};
@@ -26,18 +26,18 @@ struct mod_arch_specific { 
};



struct got_entry {

	u64 symbol_addr;	/* the real variable address */

	unsigned long symbol_addr;	/* the real variable address */

};



static inline struct got_entry emit_got_entry(u64 val)

static inline struct got_entry emit_got_entry(unsigned long val)

{

	return (struct got_entry) {val};

}



static inline struct got_entry *get_got_entry(u64 val,

static inline struct got_entry *get_got_entry(unsigned long val,

					      const struct mod_section *sec)

{

	struct got_entry *got = (struct got_entry *)sec->shdr->sh_addr;

	struct got_entry *got = (struct got_entry *)(sec->shdr->sh_addr);

	int i;

	for (i = 0; i < sec->num_entries; i++) {

		if (got[i].symbol_addr == val)
@@ -62,7 +62,9 @@ struct plt_entry { 
#define REG_T0     0x5

#define REG_T1     0x6



static inline struct plt_entry emit_plt_entry(u64 val, u64 plt, u64 got_plt)

static inline struct plt_entry emit_plt_entry(unsigned long val,

					      unsigned long plt,

					      unsigned long got_plt)

{

	/*

	 * U-Type encoding:
@@ -76,7 +78,7 @@ static inline struct plt_entry emit_plt_entry(u64 val, u64 plt, u64 got_plt) 
	 * +------------+------------+--------+----------+----------+

	 *

	 */

	u64 offset = got_plt - plt;

	unsigned long offset = got_plt - plt;

	u32 hi20 = (offset + 0x800) & 0xfffff000;

	u32 lo12 = (offset - hi20);

	return (struct plt_entry) {
@@ -86,7 +88,7 @@ static inline struct plt_entry emit_plt_entry(u64 val, u64 plt, u64 got_plt) 
	};

}



static inline int get_got_plt_idx(u64 val, const struct mod_section *sec)

static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec)

{

	struct got_entry *got_plt = (struct got_entry *)sec->shdr->sh_addr;

	int i;
@@ -97,7 +99,7 @@ static inline int get_got_plt_idx(u64 val, const struct mod_section *sec) 
	return -1;

}



static inline struct plt_entry *get_plt_entry(u64 val,

static inline struct plt_entry *get_plt_entry(unsigned long val,

					      const struct mod_section *sec_plt,

					      const struct mod_section *sec_got_plt)

{

arch/riscv/kernel/module-sections.c

+16 −14
Original line number Diff line number Diff line
@@ -9,14 +9,14 @@ 
#include <linux/kernel.h>

#include <linux/module.h>



u64 module_emit_got_entry(struct module *mod, u64 val)

unsigned long module_emit_got_entry(struct module *mod, unsigned long val)

{

	struct mod_section *got_sec = &mod->arch.got;

	int i = got_sec->num_entries;

	struct got_entry *got = get_got_entry(val, got_sec);



	if (got)

		return (u64)got;

		return (unsigned long)got;



	/* There is no duplicate entry, create a new one */

	got = (struct got_entry *)got_sec->shdr->sh_addr;
@@ -25,10 +25,10 @@ u64 module_emit_got_entry(struct module *mod, u64 val) 
	got_sec->num_entries++;

	BUG_ON(got_sec->num_entries > got_sec->max_entries);



	return (u64)&got[i];

	return (unsigned long)&got[i];

}



u64 module_emit_plt_entry(struct module *mod, u64 val)

unsigned long module_emit_plt_entry(struct module *mod, unsigned long val)

{

	struct mod_section *got_plt_sec = &mod->arch.got_plt;

	struct got_entry *got_plt;
@@ -37,27 +37,29 @@ u64 module_emit_plt_entry(struct module *mod, u64 val) 
	int i = plt_sec->num_entries;



	if (plt)

		return (u64)plt;

		return (unsigned long)plt;



	/* There is no duplicate entry, create a new one */

	got_plt = (struct got_entry *)got_plt_sec->shdr->sh_addr;

	got_plt[i] = emit_got_entry(val);

	plt = (struct plt_entry *)plt_sec->shdr->sh_addr;

	plt[i] = emit_plt_entry(val, (u64)&plt[i], (u64)&got_plt[i]);

	plt[i] = emit_plt_entry(val,

				(unsigned long)&plt[i],

				(unsigned long)&got_plt[i]);



	plt_sec->num_entries++;

	got_plt_sec->num_entries++;

	BUG_ON(plt_sec->num_entries > plt_sec->max_entries);



	return (u64)&plt[i];

	return (unsigned long)&plt[i];

}



static int is_rela_equal(const Elf64_Rela *x, const Elf64_Rela *y)

static int is_rela_equal(const Elf_Rela *x, const Elf_Rela *y)

{

	return x->r_info == y->r_info && x->r_addend == y->r_addend;

}



static bool duplicate_rela(const Elf64_Rela *rela, int idx)

static bool duplicate_rela(const Elf_Rela *rela, int idx)

{

	int i;

	for (i = 0; i < idx; i++) {
@@ -67,13 +69,13 @@ static bool duplicate_rela(const Elf64_Rela *rela, int idx) 
	return false;

}



static void count_max_entries(Elf64_Rela *relas, int num,

static void count_max_entries(Elf_Rela *relas, int num,

			      unsigned int *plts, unsigned int *gots)

{

	unsigned int type, i;



	for (i = 0; i < num; i++) {

		type = ELF64_R_TYPE(relas[i].r_info);

		type = ELF_RISCV_R_TYPE(relas[i].r_info);

		if (type == R_RISCV_CALL_PLT) {

			if (!duplicate_rela(relas, i))

				(*plts)++;
@@ -118,9 +120,9 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, 


	/* Calculate the maxinum number of entries */

	for (i = 0; i < ehdr->e_shnum; i++) {

		Elf64_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset;

		int num_rela = sechdrs[i].sh_size / sizeof(Elf64_Rela);

		Elf64_Shdr *dst_sec = sechdrs + sechdrs[i].sh_info;

		Elf_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset;

		int num_rela = sechdrs[i].sh_size / sizeof(Elf_Rela);

		Elf_Shdr *dst_sec = sechdrs + sechdrs[i].sh_info;



		if (sechdrs[i].sh_type != SHT_RELA)

			continue;

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