From 471b5e42cc7d76678314542d0ce079e5f3cfb706 Mon Sep 17 00:00:00 2001 From: Chris Brandt Date: Thu, 16 Feb 2017 18:53:29 +0100 Subject: [PATCH 01/10] ARM: 8659/1: l2c: allow CA9 optimizations to be disabled If a PL310 is added to a system, but the sideband signals are not connected, some Cortex A9 optimizations cannot be used. In particular, enabling Full Line of Zeros in the CA9 without sidebands connected will crash the system since the CA9 will expect the L2C to perform operations, yet the L2C never gets the commands. Early BRESP also does not work without sideband signals. Signed-off-by: Chris Brandt Signed-off-by: Russell King --- Documentation/devicetree/bindings/arm/l2c2x0.txt | 3 +++ arch/arm/mm/cache-l2x0.c | 13 +++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/arm/l2c2x0.txt b/Documentation/devicetree/bindings/arm/l2c2x0.txt index 917199f17965..d9650c1788f4 100644 --- a/Documentation/devicetree/bindings/arm/l2c2x0.txt +++ b/Documentation/devicetree/bindings/arm/l2c2x0.txt @@ -90,6 +90,9 @@ Optional properties: - arm,standby-mode: L2 standby mode enable. Value <0> (forcibly disable), <1> (forcibly enable), property absent (OS specific behavior, preferably retain firmware settings) +- arm,early-bresp-disable : Disable the CA9 optimization Early BRESP (PL310) +- arm,full-line-zero-disable : Disable the CA9 optimization Full line of zero + write (PL310) Example: diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 2290be390f87..808efbb89b88 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -57,6 +57,9 @@ static unsigned long sync_reg_offset = L2X0_CACHE_SYNC; struct l2x0_regs l2x0_saved_regs; +static bool l2x0_bresp_disable; +static bool l2x0_flz_disable; + /* * Common code for all cache controllers. */ @@ -620,7 +623,7 @@ static void __init l2c310_enable(void __iomem *base, unsigned num_lock) u32 aux = l2x0_saved_regs.aux_ctrl; if (rev >= L310_CACHE_ID_RTL_R2P0) { - if (cortex_a9) { + if (cortex_a9 && !l2x0_bresp_disable) { aux |= L310_AUX_CTRL_EARLY_BRESP; pr_info("L2C-310 enabling early BRESP for Cortex-A9\n"); } else if (aux & L310_AUX_CTRL_EARLY_BRESP) { @@ -629,7 +632,7 @@ static void __init l2c310_enable(void __iomem *base, unsigned num_lock) } } - if (cortex_a9) { + if (cortex_a9 && !l2x0_flz_disable) { u32 aux_cur = readl_relaxed(base + L2X0_AUX_CTRL); u32 acr = get_auxcr(); @@ -1200,6 +1203,12 @@ static void __init l2c310_of_parse(const struct device_node *np, *aux_mask &= ~L2C_AUX_CTRL_PARITY_ENABLE; } + if (of_property_read_bool(np, "arm,early-bresp-disable")) + l2x0_bresp_disable = true; + + if (of_property_read_bool(np, "arm,full-line-zero-disable")) + l2x0_flz_disable = true; + prefetch = l2x0_saved_regs.prefetch_ctrl; ret = of_property_read_u32(np, "arm,double-linefill", &val); From a96bb197693eb9e7a7221867bd944ccd6b6e12e6 Mon Sep 17 00:00:00 2001 From: Chris Brandt Date: Thu, 16 Feb 2017 18:54:39 +0100 Subject: [PATCH 02/10] ARM: 8660/1: shmobile: r7s72100: Enable L2 cache Even though L2C is specified in the DT, you still need to add the aux settings in the machine_desc. Signed-off-by: Chris Brandt Reviewed-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Signed-off-by: Russell King --- arch/arm/mach-shmobile/setup-r7s72100.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mach-shmobile/setup-r7s72100.c b/arch/arm/mach-shmobile/setup-r7s72100.c index d46639fc6849..319ca9508ec6 100644 --- a/arch/arm/mach-shmobile/setup-r7s72100.c +++ b/arch/arm/mach-shmobile/setup-r7s72100.c @@ -26,6 +26,8 @@ static const char *const r7s72100_boards_compat_dt[] __initconst = { }; DT_MACHINE_START(R7S72100_DT, "Generic R7S72100 (Flattened Device Tree)") + .l2c_aux_val = 0, + .l2c_aux_mask = ~0, .init_early = shmobile_init_delay, .init_late = shmobile_init_late, .dt_compat = r7s72100_boards_compat_dt, From f08578e6da96043ec07a695fb6f4cba27a9d22d7 Mon Sep 17 00:00:00 2001 From: Chris Brandt Date: Thu, 16 Feb 2017 18:55:55 +0100 Subject: [PATCH 03/10] ARM: 8661/1: dts: r7s72100: add l2 cache Note that early-bresp-disable and full-line-zero-disable are required because the sideband signals between the CPU and L2C were not connected in this SoC. Signed-off-by: Chris Brandt Reviewed-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Signed-off-by: Russell King --- arch/arm/boot/dts/r7s72100.dtsi | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/arm/boot/dts/r7s72100.dtsi b/arch/arm/boot/dts/r7s72100.dtsi index b8aa256bd515..1cf2bd038090 100644 --- a/arch/arm/boot/dts/r7s72100.dtsi +++ b/arch/arm/boot/dts/r7s72100.dtsi @@ -177,6 +177,7 @@ cpu@0 { compatible = "arm,cortex-a9"; reg = <0>; clock-frequency = <400000000>; + next-level-cache = <&L2>; }; }; @@ -368,6 +369,16 @@ gic: interrupt-controller@e8201000 { <0xe8202000 0x1000>; }; + L2: cache-controller@3ffff000 { + compatible = "arm,pl310-cache"; + reg = <0x3ffff000 0x1000>; + interrupts = ; + arm,early-bresp-disable; + arm,full-line-zero-disable; + cache-unified; + cache-level = <2>; + }; + i2c0: i2c@fcfee000 { #address-cells = <1>; #size-cells = <0>; From b7ede5a1f5905ac394cc8e61712a13e3c5cb7b8f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 22 Feb 2017 19:40:12 +0100 Subject: [PATCH 04/10] ARM: 8662/1: module: split core and init PLT sections Since commit 35fa91eed817 ("ARM: kernel: merge core and init PLTs"), the ARM module PLT code allocates all PLT entries in a single core section, since the overhead of having a separate init PLT section is not justified by the small number of PLT entries usually required for init code. However, the core and init module regions are allocated independently, and there is a corner case where the core region may be allocated from the VMALLOC region if the dedicated module region is exhausted, but the init region, being much smaller, can still be allocated from the module region. This puts the PLT entries out of reach of the relocated branch instructions, defeating the whole purpose of PLTs. So split the core and init PLT regions, and name the latter ".init.plt" so it gets allocated along with (and sufficiently close to) the .init sections that it serves. Also, given that init PLT entries may need to be emitted for branches that target the core module, modify the logic that disregards defined symbols to only disregard symbols that are defined in the same section. Fixes: 35fa91eed817 ("ARM: kernel: merge core and init PLTs") Cc: # v4.9+ Reported-by: Angus Clark Tested-by: Angus Clark Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King --- arch/arm/include/asm/module.h | 9 +++- arch/arm/kernel/module-plts.c | 85 ++++++++++++++++++++++++----------- arch/arm/kernel/module.lds | 1 + 3 files changed, 67 insertions(+), 28 deletions(-) diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index 464748b9fd7d..ed2319663a1e 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -18,13 +18,18 @@ enum { }; #endif +struct mod_plt_sec { + struct elf32_shdr *plt; + int plt_count; +}; + struct mod_arch_specific { #ifdef CONFIG_ARM_UNWIND struct unwind_table *unwind[ARM_SEC_MAX]; #endif #ifdef CONFIG_ARM_MODULE_PLTS - struct elf32_shdr *plt; - int plt_count; + struct mod_plt_sec core; + struct mod_plt_sec init; #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. + * Copyright (C) 2014-2017 Linaro Ltd. * * 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; + 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; - pr_debug("%s: plt=%x\n", __func__, mod->arch.plt->sh_size); + 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) } } From dd59f974bd5e04d000e38ceca1a19085d029794b Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 25 Mar 2017 00:51:32 +0100 Subject: [PATCH 05/10] ARM: 8666/1: mm: dump: Add domain to output This adds the memory domain (on non-LPAE) to the PMD and PTE dumps. This isn't in the regular PMD bits because I couldn't find a clean way to fall back to retain some of the PMD bits when reporting PTE. So this is special-cased currently. New output example: ---[ Modules ]--- 0x7f000000-0x7f001000 4K KERNEL ro x SHD MEM/CACHED/WBWA 0x7f001000-0x7f002000 4K KERNEL ro NX SHD MEM/CACHED/WBWA 0x7f002000-0x7f004000 8K KERNEL RW NX SHD MEM/CACHED/WBWA ---[ Kernel Mapping ]--- 0x80000000-0x80100000 1M KERNEL RW NX SHD 0x80100000-0x80800000 7M KERNEL ro x SHD 0x80800000-0x80b00000 3M KERNEL ro NX SHD 0x80b00000-0xa0000000 501M KERNEL RW NX SHD ... ---[ Vectors ]--- 0xffff0000-0xffff1000 4K VECTORS USR ro x SHD MEM/CACHED/WBWA 0xffff1000-0xffff2000 4K VECTORS ro x SHD MEM/CACHED/WBWA Signed-off-by: Kees Cook Signed-off-by: Russell King --- arch/arm/mm/dump.c | 54 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 10 deletions(-) diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c index 21192d6eda40..35ff45470dbf 100644 --- a/arch/arm/mm/dump.c +++ b/arch/arm/mm/dump.c @@ -17,6 +17,7 @@ #include #include +#include #include #include #include @@ -43,6 +44,7 @@ struct pg_state { unsigned long start_address; unsigned level; u64 current_prot; + const char *current_domain; }; struct prot_bits { @@ -216,7 +218,8 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits, size_t } } -static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u64 val) +static void note_page(struct pg_state *st, unsigned long addr, + unsigned int level, u64 val, const char *domain) { static const char units[] = "KMGTPE"; u64 prot = val & pg_level[level].mask; @@ -224,8 +227,10 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u if (!st->level) { st->level = level; st->current_prot = prot; + st->current_domain = domain; seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); } else if (prot != st->current_prot || level != st->level || + domain != st->current_domain || addr >= st->marker[1].start_address) { const char *unit = units; unsigned long delta; @@ -240,6 +245,8 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u unit++; } seq_printf(st->seq, "%9lu%c", delta, *unit); + if (st->current_domain) + seq_printf(st->seq, " %s", st->current_domain); if (pg_level[st->level].bits) dump_prot(st, pg_level[st->level].bits, pg_level[st->level].num); seq_printf(st->seq, "\n"); @@ -251,11 +258,13 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, u } st->start_address = addr; st->current_prot = prot; + st->current_domain = domain; st->level = level; } } -static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) +static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start, + const char *domain) { pte_t *pte = pte_offset_kernel(pmd, 0); unsigned long addr; @@ -263,25 +272,50 @@ static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) for (i = 0; i < PTRS_PER_PTE; i++, pte++) { addr = start + i * PAGE_SIZE; - note_page(st, addr, 4, pte_val(*pte)); + note_page(st, addr, 4, pte_val(*pte), domain); } } +static const char *get_domain_name(pmd_t *pmd) +{ +#ifndef CONFIG_ARM_LPAE + switch (pmd_val(*pmd) & PMD_DOMAIN_MASK) { + case PMD_DOMAIN(DOMAIN_KERNEL): + return "KERNEL "; + case PMD_DOMAIN(DOMAIN_USER): + return "USER "; + case PMD_DOMAIN(DOMAIN_IO): + return "IO "; + case PMD_DOMAIN(DOMAIN_VECTORS): + return "VECTORS"; + default: + return "unknown"; + } +#endif + return NULL; +} + static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) { pmd_t *pmd = pmd_offset(pud, 0); unsigned long addr; unsigned i; + const char *domain; for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { addr = start + i * PMD_SIZE; + domain = get_domain_name(pmd); if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) - note_page(st, addr, 3, pmd_val(*pmd)); + note_page(st, addr, 3, pmd_val(*pmd), domain); else - walk_pte(st, pmd, addr); + walk_pte(st, pmd, addr, domain); - if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1])) - note_page(st, addr + SECTION_SIZE, 3, pmd_val(pmd[1])); + if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1])) { + addr += SECTION_SIZE; + pmd++; + domain = get_domain_name(pmd); + note_page(st, addr, 3, pmd_val(*pmd), domain); + } } } @@ -296,7 +330,7 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) if (!pud_none(*pud)) { walk_pmd(st, pud, addr); } else { - note_page(st, addr, 2, pud_val(*pud)); + note_page(st, addr, 2, pud_val(*pud), NULL); } } } @@ -317,11 +351,11 @@ static void walk_pgd(struct seq_file *m) if (!pgd_none(*pgd)) { walk_pud(&st, pgd, addr); } else { - note_page(&st, addr, 1, pgd_val(*pgd)); + note_page(&st, addr, 1, pgd_val(*pgd), NULL); } } - note_page(&st, 0, 0, 0); + note_page(&st, 0, 0, 0, NULL); } static int ptdump_show(struct seq_file *m, void *v) From ea2d9a96b6abe57d72d39a7af24e0120f5df0a8c Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sun, 19 Mar 2017 17:23:31 +0100 Subject: [PATCH 06/10] ARM: 8663/1: wire up HWCAP/HWCAP2 feature bits to the CPU modalias Wire up the generic support for exposing CPU feature bits via the modalias in /sys/device/system/cpu. This allows udev to automatically load modules for things like crypto algorithms that are implemented using optional instructions. Since it is non-trivial to transparantly support both HWCAP and HWCAP2 capabilities in the cpu_feature() macro (which allows a module's hwcap dependency and init routine to be declared using a single invocation of module_cpu_feature_match()), support only HWCAP2 for now, which covers the capabilities that are most likely to be useful in this manner. Module dependencies on HWCAP will need to be declared explicitly via a MODULE_DEVICE_TABLE(cpu, ...) declaration. Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King --- arch/arm/Kconfig | 1 + arch/arm/include/asm/cpufeature.h | 38 +++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) create mode 100644 arch/arm/include/asm/cpufeature.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 0d4e71b42c77..64b43a84a1eb 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -27,6 +27,7 @@ config ARM select GENERIC_ALLOCATOR select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) select GENERIC_CLOCKEVENTS_BROADCAST if SMP + select GENERIC_CPU_AUTOPROBE select GENERIC_EARLY_IOREMAP select GENERIC_IDLE_POLL_SETUP select GENERIC_IRQ_PROBE diff --git a/arch/arm/include/asm/cpufeature.h b/arch/arm/include/asm/cpufeature.h new file mode 100644 index 000000000000..6d425191d01d --- /dev/null +++ b/arch/arm/include/asm/cpufeature.h @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2017 Linaro Ltd. + * + * 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 + * published by the Free Software Foundation. + */ + +#ifndef __ASM_CPUFEATURE_H +#define __ASM_CPUFEATURE_H + +#include +#include + +/* + * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number + * of optional CPU features it defines, ARM's CPU hardware capability bits have + * been distributed over separate elf_hwcap and elf_hwcap2 variables, each of + * which covers a subset of the available CPU features. + * + * Currently, only a few of those are suitable for automatic module loading + * (which is the primary use case of this facility) and those happen to be all + * covered by HWCAP2. So let's only cover those via the cpu_feature() + * convenience macro for now (which is used by module_cpu_feature_match()). + * However, all capabilities are exposed via the modalias, and can be matched + * using an explicit MODULE_DEVICE_TABLE() that uses __hwcap_feature() directly. + */ +#define MAX_CPU_FEATURES 64 +#define __hwcap_feature(x) ilog2(HWCAP_ ## x) +#define __hwcap2_feature(x) (32 + ilog2(HWCAP2_ ## x)) +#define cpu_feature(x) __hwcap2_feature(x) + +static inline bool cpu_have_feature(unsigned int num) +{ + return num < 32 ? elf_hwcap & BIT(num) : elf_hwcap2 & BIT(num - 32); +} + +#endif From b089c31c519c3906c14801b6ec483e18a5152a50 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Mon, 10 Apr 2017 11:13:59 +0100 Subject: [PATCH 07/10] ARM: 8667/3: Fix memory attribute inconsistencies when using fixmap To cope with the variety in ARM architectures and configurations, the pagetable attributes for kernel memory are generated at runtime to match the system the kernel finds itself on. This calculated value is stored in pgprot_kernel. However, when early fixmap support was added for ARM (commit a5f4c561b3b1) the attributes used for mappings were hard coded because pgprot_kernel is not set up early enough. Unfortunately, when fixmap is used after early boot this means the memory being mapped can have different attributes to existing mappings, potentially leading to unpredictable behaviour. A specific problem also exists due to the hard coded values not include the 'shareable' attribute which means on systems where this matters (e.g. those with multiple CPU clusters) the cache contents for a memory location can become inconsistent between CPUs. To resolve these issues we change fixmap to use the same memory attributes (from pgprot_kernel) that the rest of the kernel uses. To enable this we need to refactor the initialisation code so build_mem_type_table() is called early enough. Note, that relies on early param parsing for memory type overrides passed via the kernel command line, so we need to make sure this call is still after parse_early_params(). [ardb: keep early_fixmap_init() before param parsing, for earlycon] Fixes: a5f4c561b3b1 ("ARM: 8415/1: early fixmap support for earlycon") Cc: # v4.3+ Tested-by: afzal mohammed Signed-off-by: Jon Medhurst Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King --- arch/arm/include/asm/fixmap.h | 2 +- arch/arm/kernel/setup.c | 4 ++-- arch/arm/mm/mmu.c | 16 +++++++++++++--- 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 5c17d2dec777..8f967d1373f6 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -41,7 +41,7 @@ static const enum fixed_addresses __end_of_fixed_addresses = #define FIXMAP_PAGE_COMMON (L_PTE_YOUNG | L_PTE_PRESENT | L_PTE_XN | L_PTE_DIRTY) -#define FIXMAP_PAGE_NORMAL (FIXMAP_PAGE_COMMON | L_PTE_MT_WRITEBACK) +#define FIXMAP_PAGE_NORMAL (pgprot_kernel | L_PTE_XN) #define FIXMAP_PAGE_RO (FIXMAP_PAGE_NORMAL | L_PTE_RDONLY) /* Used by set_fixmap_(io|nocache), both meant for mapping a device */ diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index f4e54503afa9..32e1a9513dc7 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -80,7 +80,7 @@ __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 early_mm_init(const struct machine_desc *); extern void adjust_lowmem_bounds(void); extern enum reboot_mode reboot_mode; extern void setup_dma_zone(const struct machine_desc *desc); @@ -1088,7 +1088,7 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); #ifdef CONFIG_MMU - early_paging_init(mdesc); + early_mm_init(mdesc); #endif setup_dma_zone(mdesc); xen_early_init(); diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4e016d7f37b3..347cca965783 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -414,6 +414,11 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) FIXADDR_END); BUG_ON(idx >= __end_of_fixed_addresses); + /* we only support device mappings until pgprot_kernel has been set */ + if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) && + pgprot_val(pgprot_kernel) == 0)) + return; + if (pgprot_val(prot)) set_pte_at(NULL, vaddr, pte, pfn_pte(phys >> PAGE_SHIFT, prot)); @@ -1492,7 +1497,7 @@ pgtables_remap lpae_pgtables_remap_asm; * early_paging_init() recreates boot time page table setup, allowing machines * to switch over to a high (>4G) address space on LPAE systems */ -void __init early_paging_init(const struct machine_desc *mdesc) +static void __init early_paging_init(const struct machine_desc *mdesc) { pgtables_remap *lpae_pgtables_remap; unsigned long pa_pgd; @@ -1560,7 +1565,7 @@ void __init early_paging_init(const struct machine_desc *mdesc) #else -void __init early_paging_init(const struct machine_desc *mdesc) +static void __init early_paging_init(const struct machine_desc *mdesc) { long long offset; @@ -1616,7 +1621,6 @@ void __init paging_init(const struct machine_desc *mdesc) { void *zero_page; - build_mem_type_table(); prepare_page_table(); map_lowmem(); memblock_set_current_limit(arm_lowmem_limit); @@ -1636,3 +1640,9 @@ void __init paging_init(const struct machine_desc *mdesc) empty_zero_page = virt_to_page(zero_page); __flush_dcache_page(NULL, empty_zero_page); } + +void __init early_mm_init(const struct machine_desc *mdesc) +{ + build_mem_type_table(); + early_paging_init(mdesc); +} From 6f05d0761af612e04572ba4d65b4c0274a88444f Mon Sep 17 00:00:00 2001 From: Abel Vesa Date: Mon, 3 Apr 2017 23:58:54 +0100 Subject: [PATCH 08/10] ARM: 8668/1: ftrace: Fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTER The support for dynamic ftrace with CONFIG_DEBUG_RODATA involves overriding the weak arch_ftrace_update_code() with a variant which makes the kernel text writable around the patching. This override was however added under the CONFIG_OLD_MCOUNT ifdef, and CONFIG_OLD_MCOUNT is only enabled if frame pointers are enabled. This leads to non-functional dynamic ftrace (ftrace triggers a WARN_ON()) when CONFIG_DEBUG_RODATA is enabled and CONFIG_FRAME_POINTER is not. Move the override out of that ifdef and into the CONFIG_DYNAMIC_FTRACE ifdef where it belongs. Fixes: 80d6b0c2eed2a ("ARM: mm: allow text and rodata sections to be read-only") Suggested-by: Nicolai Stange Suggested-by: Rabin Vincent Signed-off-by: Abel Vesa Acked-by: Rabin Vincent Signed-off-by: Russell King --- arch/arm/kernel/ftrace.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 3f1759411d51..414e60ed0257 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -29,11 +29,6 @@ #endif #ifdef CONFIG_DYNAMIC_FTRACE -#ifdef CONFIG_OLD_MCOUNT -#define OLD_MCOUNT_ADDR ((unsigned long) mcount) -#define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old) - -#define OLD_NOP 0xe1a00000 /* mov r0, r0 */ static int __ftrace_modify_code(void *data) { @@ -51,6 +46,12 @@ void arch_ftrace_update_code(int command) stop_machine(__ftrace_modify_code, &command, NULL); } +#ifdef CONFIG_OLD_MCOUNT +#define OLD_MCOUNT_ADDR ((unsigned long) mcount) +#define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old) + +#define OLD_NOP 0xe1a00000 /* mov r0, r0 */ + static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec) { return rec->arch.old_mcount ? OLD_NOP : NOP; From b70cd406d7fe9976962d621d8c60d324eb47d284 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Mon, 24 Apr 2017 10:41:53 +0100 Subject: [PATCH 09/10] ARM: 8671/1: V7M: Preserve registers across switch from Thread to Handler mode According to ARMv7 ARM, when exception is taken content of r0-r3, r12 is unknown (see ExceptionTaken() pseudocode). Even though existent implementations keep these register unchanged, preserve them to be in line with architecture. Reported-by: Dobromir Stefanov Signed-off-by: Vladimir Murzin Signed-off-by: Russell King --- arch/arm/mm/proc-v7m.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S index 8dea61640cc1..11ae6b847ad0 100644 --- a/arch/arm/mm/proc-v7m.S +++ b/arch/arm/mm/proc-v7m.S @@ -135,9 +135,11 @@ __v7m_setup_cont: dsb mov r6, lr @ save LR ldr sp, =init_thread_union + THREAD_START_SP + stmia sp, {r0-r3, r12} cpsie i svc #0 1: cpsid i + ldmia sp, {r0-r3, r12} str r5, [r12, #11 * 4] @ restore the original SVC vector entry mov lr, r6 @ restore LR From 11ce4b33aedc65198d7bc9669344ebca5ee36a41 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Tue, 25 Apr 2017 21:20:52 +0100 Subject: [PATCH 10/10] ARM: 8672/1: mm: remove tasklist locking from update_sections_early() The below backtrace can be observed on -rt kernel with CONFIG_DEBUG_MODULE_RONX (4.9 kernel CONFIG_DEBUG_RODATA) option enabled: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993 in_atomic(): 1, irqs_disabled(): 128, pid: 14, name: migration/0 1 lock held by migration/0/14: #0: (tasklist_lock){+.+...}, at: [] update_sections_early+0x24/0xdc irq event stamp: 38 hardirqs last enabled at (37): [] _raw_spin_unlock_irq+0x24/0x68 hardirqs last disabled at (38): [] multi_cpu_stop+0xd8/0x138 softirqs last enabled at (0): [] copy_process.part.5+0x238/0x1b64 softirqs last disabled at (0): [< (null)>] (null) Preemption disabled at: [] cpu_stopper_thread+0x80/0x10c CPU: 0 PID: 14 Comm: migration/0 Not tainted 4.9.21-rt16-02220-g49e319c #15 Hardware name: Generic DRA74X (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xa8/0xd4) [] (dump_stack) from [] (___might_sleep+0x1bc/0x2ac) [] (___might_sleep) from [] (__rt_spin_lock+0x1c/0x30) [] (__rt_spin_lock) from [] (rt_read_lock+0x54/0x68) [] (rt_read_lock) from [] (update_sections_early+0x24/0xdc) [] (update_sections_early) from [] (__fix_kernmem_perms+0x10/0x1c) [] (__fix_kernmem_perms) from [] (multi_cpu_stop+0x100/0x138) [] (multi_cpu_stop) from [] (cpu_stopper_thread+0x88/0x10c) [] (cpu_stopper_thread) from [] (smpboot_thread_fn+0x174/0x31c) [] (smpboot_thread_fn) from [] (kthread+0xf0/0x108) [] (kthread) from [] (ret_from_fork+0x14/0x3c) Freeing unused kernel memory: 1024K (c0d00000 - c0e00000) The stop_machine() is called with cpus = NULL from fix_kernmem_perms() and mark_rodata_ro() which means only one CPU will execute update_sections_early() while all other CPUs will spin and wait. Hence, it's safe to remove tasklist locking from update_sections_early(). As part of this change also mark functions which are local to this module as static. Signed-off-by: Grygorii Strashko Acked-by: Laura Abbott Acked-by: Kees Cook Signed-off-by: Russell King --- arch/arm/mm/init.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 1d8558ff9827..ad80548325fe 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -709,34 +709,37 @@ void set_section_perms(struct section_perm *perms, int n, bool set, } +/** + * update_sections_early intended to be called only through stop_machine + * framework and executed by only one CPU while all other CPUs will spin and + * wait, so no locking is required in this function. + */ static void update_sections_early(struct section_perm perms[], int n) { struct task_struct *t, *s; - read_lock(&tasklist_lock); for_each_process(t) { if (t->flags & PF_KTHREAD) continue; for_each_thread(t, s) set_section_perms(perms, n, true, s->mm); } - read_unlock(&tasklist_lock); set_section_perms(perms, n, true, current->active_mm); set_section_perms(perms, n, true, &init_mm); } -int __fix_kernmem_perms(void *unused) +static int __fix_kernmem_perms(void *unused) { update_sections_early(nx_perms, ARRAY_SIZE(nx_perms)); return 0; } -void fix_kernmem_perms(void) +static void fix_kernmem_perms(void) { stop_machine(__fix_kernmem_perms, NULL, NULL); } -int __mark_rodata_ro(void *unused) +static int __mark_rodata_ro(void *unused) { update_sections_early(ro_perms, ARRAY_SIZE(ro_perms)); return 0;