diff options
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/armksyms.c | 4 | ||||
-rw-r--r-- | arch/arm/kernel/module-plts.c | 87 | ||||
-rw-r--r-- | arch/arm/kernel/module.lds | 1 | ||||
-rw-r--r-- | arch/arm/kernel/setup.c | 10 | ||||
-rw-r--r-- | arch/arm/kernel/smccc-call.S | 14 | ||||
-rw-r--r-- | arch/arm/kernel/traps.c | 28 |
6 files changed, 97 insertions, 47 deletions
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 7e45f69a0ddc..8e8d20cdbce7 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -178,6 +178,6 @@ EXPORT_SYMBOL(__pv_offset); #endif #ifdef CONFIG_HAVE_ARM_SMCCC -EXPORT_SYMBOL(arm_smccc_smc); -EXPORT_SYMBOL(arm_smccc_hvc); +EXPORT_SYMBOL(__arm_smccc_smc); +EXPORT_SYMBOL(__arm_smccc_hvc); #endif diff --git a/arch/arm/kernel/module-plts.c b/arch/arm/kernel/module-plts.c index 3a5cba90c971..3d0c2e4dda1d 100644 --- a/arch/arm/kernel/module-plts.c +++ b/arch/arm/kernel/module-plts.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> + * Copyright (C) 2014-2017 Linaro Ltd. <ard.biesheuvel@linaro.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -31,9 +31,17 @@ struct plt_entries { u32 lit[PLT_ENT_COUNT]; }; +static bool in_init(const struct module *mod, unsigned long loc) +{ + return loc - (u32)mod->init_layout.base < mod->init_layout.size; +} + u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) { - struct plt_entries *plt = (struct plt_entries *)mod->arch.plt->sh_addr; + struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core : + &mod->arch.init; + + struct plt_entries *plt = (struct plt_entries *)pltsec->plt->sh_addr; int idx = 0; /* @@ -41,9 +49,9 @@ u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) * relocations are sorted, this will be the last entry we allocated. * (if one exists). */ - if (mod->arch.plt_count > 0) { - plt += (mod->arch.plt_count - 1) / PLT_ENT_COUNT; - idx = (mod->arch.plt_count - 1) % PLT_ENT_COUNT; + if (pltsec->plt_count > 0) { + plt += (pltsec->plt_count - 1) / PLT_ENT_COUNT; + idx = (pltsec->plt_count - 1) % PLT_ENT_COUNT; if (plt->lit[idx] == val) return (u32)&plt->ldr[idx]; @@ -53,8 +61,8 @@ u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) plt++; } - mod->arch.plt_count++; - BUG_ON(mod->arch.plt_count * PLT_ENT_SIZE > mod->arch.plt->sh_size); + pltsec->plt_count++; + BUG_ON(pltsec->plt_count * PLT_ENT_SIZE > pltsec->plt->sh_size); if (!idx) /* Populate a new set of entries */ @@ -129,7 +137,7 @@ static bool duplicate_rel(Elf32_Addr base, const Elf32_Rel *rel, int num) /* Count how many PLT entries we may need */ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base, - const Elf32_Rel *rel, int num) + const Elf32_Rel *rel, int num, Elf32_Word dstidx) { unsigned int ret = 0; const Elf32_Sym *s; @@ -144,13 +152,17 @@ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base, case R_ARM_THM_JUMP24: /* * We only have to consider branch targets that resolve - * to undefined symbols. This is not simply a heuristic, - * it is a fundamental limitation, since the PLT itself - * is part of the module, and needs to be within range - * as well, so modules can never grow beyond that limit. + * to symbols that are defined in a different section. + * This is not simply a heuristic, it is a fundamental + * limitation, since there is no guaranteed way to emit + * PLT entries sufficiently close to the branch if the + * section size exceeds the range of a branch + * instruction. So ignore relocations against defined + * symbols if they live in the same section as the + * relocation target. */ s = syms + ELF32_R_SYM(rel[i].r_info); - if (s->st_shndx != SHN_UNDEF) + if (s->st_shndx == dstidx) break; /* @@ -161,7 +173,12 @@ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base, * So we need to support them, but there is no need to * take them into consideration when trying to optimize * this code. So let's only check for duplicates when - * the addend is zero. + * the addend is zero. (Note that calls into the core + * module via init PLT entries could involve section + * relative symbol references with non-zero addends, for + * which we may end up emitting duplicates, but the init + * PLT is released along with the rest of the .init + * region as soon as module loading completes.) */ if (!is_zero_addend_relocation(base, rel + i) || !duplicate_rel(base, rel, i)) @@ -174,7 +191,8 @@ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base, int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { - unsigned long plts = 0; + unsigned long core_plts = 0; + unsigned long init_plts = 0; Elf32_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; Elf32_Sym *syms = NULL; @@ -184,13 +202,15 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, */ for (s = sechdrs; s < sechdrs_end; ++s) { if (strcmp(".plt", secstrings + s->sh_name) == 0) - mod->arch.plt = s; + mod->arch.core.plt = s; + else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) + mod->arch.init.plt = s; else if (s->sh_type == SHT_SYMTAB) syms = (Elf32_Sym *)s->sh_addr; } - if (!mod->arch.plt) { - pr_err("%s: module PLT section missing\n", mod->name); + if (!mod->arch.core.plt || !mod->arch.init.plt) { + pr_err("%s: module PLT section(s) missing\n", mod->name); return -ENOEXEC; } if (!syms) { @@ -213,16 +233,29 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, /* sort by type and symbol index */ sort(rels, numrels, sizeof(Elf32_Rel), cmp_rel, NULL); - plts += count_plts(syms, dstsec->sh_addr, rels, numrels); + if (strncmp(secstrings + dstsec->sh_name, ".init", 5) != 0) + core_plts += count_plts(syms, dstsec->sh_addr, rels, + numrels, s->sh_info); + else + init_plts += count_plts(syms, dstsec->sh_addr, rels, + numrels, s->sh_info); } - mod->arch.plt->sh_type = SHT_NOBITS; - mod->arch.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; - mod->arch.plt->sh_addralign = L1_CACHE_BYTES; - mod->arch.plt->sh_size = round_up(plts * PLT_ENT_SIZE, - sizeof(struct plt_entries)); - mod->arch.plt_count = 0; - - pr_debug("%s: plt=%x\n", __func__, mod->arch.plt->sh_size); + mod->arch.core.plt->sh_type = SHT_NOBITS; + mod->arch.core.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; + mod->arch.core.plt->sh_addralign = L1_CACHE_BYTES; + mod->arch.core.plt->sh_size = round_up(core_plts * PLT_ENT_SIZE, + sizeof(struct plt_entries)); + mod->arch.core.plt_count = 0; + + mod->arch.init.plt->sh_type = SHT_NOBITS; + mod->arch.init.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; + mod->arch.init.plt->sh_addralign = L1_CACHE_BYTES; + mod->arch.init.plt->sh_size = round_up(init_plts * PLT_ENT_SIZE, + sizeof(struct plt_entries)); + mod->arch.init.plt_count = 0; + + pr_debug("%s: plt=%x, init.plt=%x\n", __func__, + mod->arch.core.plt->sh_size, mod->arch.init.plt->sh_size); return 0; } diff --git a/arch/arm/kernel/module.lds b/arch/arm/kernel/module.lds index 05881e2b414c..eacb5c67f61e 100644 --- a/arch/arm/kernel/module.lds +++ b/arch/arm/kernel/module.lds @@ -1,3 +1,4 @@ SECTIONS { .plt : { BYTE(0) } + .init.plt : { BYTE(0) } } diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 34e3f3c45634..f4e54503afa9 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -81,7 +81,7 @@ __setup("fpe=", fpe_setup); extern void init_default_cache_policy(unsigned long); extern void paging_init(const struct machine_desc *desc); extern void early_paging_init(const struct machine_desc *); -extern void sanity_check_meminfo(void); +extern void adjust_lowmem_bounds(void); extern enum reboot_mode reboot_mode; extern void setup_dma_zone(const struct machine_desc *desc); @@ -1093,8 +1093,14 @@ void __init setup_arch(char **cmdline_p) setup_dma_zone(mdesc); xen_early_init(); efi_init(); - sanity_check_meminfo(); + /* + * Make sure the calculation for lowmem/highmem is set appropriately + * before reserving/allocating any mmeory + */ + adjust_lowmem_bounds(); arm_memblock_init(mdesc); + /* Memory may have been removed so recalculate the bounds. */ + adjust_lowmem_bounds(); early_ioremap_reset(); diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S index 2e48b674aab1..e5d43066b889 100644 --- a/arch/arm/kernel/smccc-call.S +++ b/arch/arm/kernel/smccc-call.S @@ -46,17 +46,19 @@ UNWIND( .fnend) /* * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2, * unsigned long a3, unsigned long a4, unsigned long a5, - * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res, + * struct arm_smccc_quirk *quirk) */ -ENTRY(arm_smccc_smc) +ENTRY(__arm_smccc_smc) SMCCC SMCCC_SMC -ENDPROC(arm_smccc_smc) +ENDPROC(__arm_smccc_smc) /* * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2, * unsigned long a3, unsigned long a4, unsigned long a5, - * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res, + * struct arm_smccc_quirk *quirk) */ -ENTRY(arm_smccc_hvc) +ENTRY(__arm_smccc_hvc) SMCCC SMCCC_HVC -ENDPROC(arm_smccc_hvc) +ENDPROC(__arm_smccc_hvc) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 9688ec0c6ef4..1b304897aa12 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -152,30 +152,26 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom, set_fs(fs); } -static void dump_instr(const char *lvl, struct pt_regs *regs) +static void __dump_instr(const char *lvl, struct pt_regs *regs) { unsigned long addr = instruction_pointer(regs); const int thumb = thumb_mode(regs); const int width = thumb ? 4 : 8; - mm_segment_t fs; char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; int i; /* - * We need to switch to kernel mode so that we can use __get_user - * to safely read from kernel space. Note that we now dump the - * code first, just in case the backtrace kills us. + * Note that we now dump the code first, just in case the backtrace + * kills us. */ - fs = get_fs(); - set_fs(KERNEL_DS); for (i = -4; i < 1 + !!thumb; i++) { unsigned int val, bad; if (thumb) - bad = __get_user(val, &((u16 *)addr)[i]); + bad = get_user(val, &((u16 *)addr)[i]); else - bad = __get_user(val, &((u32 *)addr)[i]); + bad = get_user(val, &((u32 *)addr)[i]); if (!bad) p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", @@ -186,8 +182,20 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) } } printk("%sCode: %s\n", lvl, str); +} - set_fs(fs); +static void dump_instr(const char *lvl, struct pt_regs *regs) +{ + mm_segment_t fs; + + if (!user_mode(regs)) { + fs = get_fs(); + set_fs(KERNEL_DS); + __dump_instr(lvl, regs); + set_fs(fs); + } else { + __dump_instr(lvl, regs); + } } #ifdef CONFIG_ARM_UNWIND |