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author | 2018-03-15 16:50:42 +0800 | |
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committer | 2018-04-02 20:00:54 -0700 | |
commit | b8bde0ef12bd43f013d879973a1900930bfb95ee (patch) | |
tree | 953afd76c9ed57a34ed2ee3c042c4e061bc9d5dc /arch/riscv/kernel/module-sections.c | |
parent | RISC-V: Add sections of PLT and GOT for kernel module (diff) | |
download | linux-b8bde0ef12bd43f013d879973a1900930bfb95ee.tar.gz linux-b8bde0ef12bd43f013d879973a1900930bfb95ee.tar.bz2 linux-b8bde0ef12bd43f013d879973a1900930bfb95ee.zip |
RISC-V: Add section of GOT.PLT for kernel module
Separate the function symbol address from .plt to .got.plt section.
The original plt entry has trampoline code with symbol address,
there is a 32-bit padding bwtween jar instruction and symbol address.
Extract the symbol address to .got.plt to reduce the module size.
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv/kernel/module-sections.c')
-rw-r--r-- | arch/riscv/kernel/module-sections.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/riscv/kernel/module-sections.c b/arch/riscv/kernel/module-sections.c index 94ba1551eac3..bbbd26e19bfd 100644 --- a/arch/riscv/kernel/module-sections.c +++ b/arch/riscv/kernel/module-sections.c @@ -30,18 +30,23 @@ u64 module_emit_got_entry(struct module *mod, u64 val) u64 module_emit_plt_entry(struct module *mod, u64 val) { + struct mod_section *got_plt_sec = &mod->arch.got_plt; + struct got_entry *got_plt; struct mod_section *plt_sec = &mod->arch.plt; - struct plt_entry *plt = get_plt_entry(val, plt_sec); + struct plt_entry *plt = get_plt_entry(val, plt_sec, got_plt_sec); int i = plt_sec->num_entries; if (plt) return (u64)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); + plt[i] = emit_plt_entry(val, (u64)&plt[i], (u64)&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]; @@ -94,6 +99,8 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.plt.shdr = sechdrs + i; else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got")) mod->arch.got.shdr = sechdrs + i; + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got.plt")) + mod->arch.got_plt.shdr = sechdrs + i; } if (!mod->arch.plt.shdr) { @@ -104,6 +111,10 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, pr_err("%s: module GOT section(s) missing\n", mod->name); return -ENOEXEC; } + if (!mod->arch.got_plt.shdr) { + pr_err("%s: module GOT.PLT section(s) missing\n", mod->name); + return -ENOEXEC; + } /* Calculate the maxinum number of entries */ for (i = 0; i < ehdr->e_shnum; i++) { @@ -135,5 +146,11 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.got.num_entries = 0; mod->arch.got.max_entries = num_gots; + mod->arch.got_plt.shdr->sh_type = SHT_NOBITS; + mod->arch.got_plt.shdr->sh_flags = SHF_ALLOC; + mod->arch.got_plt.shdr->sh_addralign = L1_CACHE_BYTES; + mod->arch.got_plt.shdr->sh_size = (num_plts + 1) * sizeof(struct got_entry); + mod->arch.got_plt.num_entries = 0; + mod->arch.got_plt.max_entries = num_plts; return 0; } |