diff --git a/arch/csky/abiv1/inc/abi/vdso.h b/arch/csky/abiv1/inc/abi/vdso.h index 14352f524f1d11a4612c9628729db8121e82107c..9e6d0a2fdd2b7613908b21231cc5ec7a9d43908a 100644 --- a/arch/csky/abiv1/inc/abi/vdso.h +++ b/arch/csky/abiv1/inc/abi/vdso.h @@ -1,17 +1,9 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#include +#ifndef __ABI_CSKY_VDSO_H +#define __ABI_CSKY_VDSO_H -static inline int setup_vdso_page(unsigned short *ptr) -{ - int err = 0; +/* movi r1, 127; addi r1, (139 - 127) */ +#define SET_SYSCALL_ID .long 0x20b167f1 - /* movi r1, 127 */ - err |= __put_user(0x67f1, ptr + 0); - /* addi r1, (139 - 127) */ - err |= __put_user(0x20b1, ptr + 1); - /* trap 0 */ - err |= __put_user(0x0008, ptr + 2); - - return err; -} +#endif /* __ABI_CSKY_VDSO_H */ diff --git a/arch/csky/abiv2/inc/abi/vdso.h b/arch/csky/abiv2/inc/abi/vdso.h index b60d4a07032636e862840ee0d0432e94a3b97b67..40fd10d893ff2239ca254090d54427ef06137b84 100644 --- a/arch/csky/abiv2/inc/abi/vdso.h +++ b/arch/csky/abiv2/inc/abi/vdso.h @@ -3,21 +3,7 @@ #ifndef __ABI_CSKY_VDSO_H #define __ABI_CSKY_VDSO_H -#include +/* movi r7, 173 */ +#define SET_SYSCALL_ID .long 0x008bea07 -static inline int setup_vdso_page(unsigned short *ptr) -{ - int err = 0; - - /* movi r7, 173 */ - err |= __put_user(0xea07, ptr); - err |= __put_user(0x008b, ptr+1); - - /* trap 0 */ - err |= __put_user(0xc000, ptr+2); - err |= __put_user(0x2020, ptr+3); - - return err; -} - -#endif /* __ABI_CSKY_STRING_H */ +#endif /* __ABI_CSKY_VDSO_H */ diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h index d963d691f3a1f75e18348639aa0181d173df8540..12c5d638e784e08b998559ad8b1efaf0d189c7a8 100644 --- a/arch/csky/include/asm/vdso.h +++ b/arch/csky/include/asm/vdso.h @@ -3,10 +3,23 @@ #ifndef __ASM_CSKY_VDSO_H #define __ASM_CSKY_VDSO_H -#include +#include -struct csky_vdso { - unsigned short rt_signal_retcode[4]; +struct vdso_data { }; +/* + * The VDSO symbols are mapped into Linux so we can just use regular symbol + * addressing to get their offsets in userspace. The symbols are mapped at an + * offset of 0, but since the linker must support setting weak undefined + * symbols to the absolute address 0 it also happens to support other low + * addresses even when the code model suggests those low addresses would not + * otherwise be availiable. + */ +#define VDSO_SYMBOL(base, name) \ +({ \ + extern const char __vdso_##name[]; \ + (void __user *)((unsigned long)(base) + __vdso_##name); \ +}) + #endif /* __ASM_CSKY_VDSO_H */ diff --git a/arch/csky/kernel/Makefile b/arch/csky/kernel/Makefile index 37f37c0e934a8f36c95f7e2e0654ecf63b08e503..6c0f36010ed0509a8b1a89dbc0a518a36146da2b 100644 --- a/arch/csky/kernel/Makefile +++ b/arch/csky/kernel/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only extra-y := head.o vmlinux.lds -obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o +obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o vdso/ obj-y += power.o syscall.o syscall_table.o setup.o obj-y += process.o cpu-probe.o ptrace.o stacktrace.o obj-y += probes/ diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c index 37ea64ed3c12bc96ab86a0caa953a0f32c309bc8..312f046d452d87e19f6da7230d4ab50db1140ed3 100644 --- a/arch/csky/kernel/signal.c +++ b/arch/csky/kernel/signal.c @@ -134,7 +134,6 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { struct rt_sigframe *frame; int err = 0; - struct csky_vdso *vdso = current->mm->context.vdso; frame = get_sigframe(ksig, regs, sizeof(*frame)); if (!access_ok(frame, sizeof(*frame))) @@ -152,7 +151,8 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) return -EFAULT; /* Set up to return from userspace. */ - regs->lr = (unsigned long)(vdso->rt_signal_retcode); + regs->lr = (unsigned long)VDSO_SYMBOL( + current->mm->context.vdso, rt_sigreturn); /* * Set up registers for signal handler. diff --git a/arch/csky/kernel/vdso.c b/arch/csky/kernel/vdso.c index abc3dbc658d4979aa9260561a73b60225796561a..839523920843d00f960d8609b6fd35d475239bc2 100644 --- a/arch/csky/kernel/vdso.c +++ b/arch/csky/kernel/vdso.c @@ -1,86 +1,103 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. -#include -#include -#include -#include -#include #include #include -#include -#include -#include +#include +#include +#include +#include #include -#include -static struct page *vdso_page; +extern char vdso_start[], vdso_end[]; -static int __init init_vdso(void) -{ - struct csky_vdso *vdso; - int err = 0; - - vdso_page = alloc_page(GFP_KERNEL); - if (!vdso_page) - panic("Cannot allocate vdso"); +static unsigned int vdso_pages; +static struct page **vdso_pagelist; - vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL); - if (!vdso) - panic("Cannot map vdso"); +/* + * The vDSO data page. + */ +static union { + struct vdso_data data; + u8 page[PAGE_SIZE]; +} vdso_data_store __page_aligned_data; +struct vdso_data *vdso_data = &vdso_data_store.data; - clear_page(vdso); - - err = setup_vdso_page(vdso->rt_signal_retcode); - if (err) - panic("Cannot set signal return code, err: %x.", err); +static int __init vdso_init(void) +{ + unsigned int i; + + vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; + vdso_pagelist = + kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); + if (unlikely(vdso_pagelist == NULL)) { + pr_err("vdso: pagelist allocation failed\n"); + return -ENOMEM; + } - dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16); + for (i = 0; i < vdso_pages; i++) { + struct page *pg; - vunmap(vdso); + pg = virt_to_page(vdso_start + (i << PAGE_SHIFT)); + vdso_pagelist[i] = pg; + } + vdso_pagelist[i] = virt_to_page(vdso_data); return 0; } -subsys_initcall(init_vdso); +arch_initcall(vdso_init); -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp) { - int ret; - unsigned long addr; struct mm_struct *mm = current->mm; + unsigned long vdso_base, vdso_len; + int ret; - mmap_write_lock(mm); + vdso_len = (vdso_pages + 1) << PAGE_SHIFT; - addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0); - if (IS_ERR_VALUE(addr)) { - ret = addr; - goto up_fail; + mmap_write_lock(mm); + vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0); + if (IS_ERR_VALUE(vdso_base)) { + ret = vdso_base; + goto end; } - ret = install_special_mapping( - mm, - addr, - PAGE_SIZE, - VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - &vdso_page); - if (ret) - goto up_fail; + /* + * Put vDSO base into mm struct. We need to do this before calling + * install_special_mapping or the perf counter mmap tracking code + * will fail to recognise it as a vDSO (since arch_vma_name fails). + */ + mm->context.vdso = (void *)vdso_base; + + ret = + install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, + (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC), + vdso_pagelist); + + if (unlikely(ret)) { + mm->context.vdso = NULL; + goto end; + } - mm->context.vdso = (void *)addr; + vdso_base += (vdso_pages << PAGE_SHIFT); + ret = install_special_mapping(mm, vdso_base, PAGE_SIZE, + (VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]); -up_fail: + if (unlikely(ret)) + mm->context.vdso = NULL; +end: mmap_write_unlock(mm); return ret; } const char *arch_vma_name(struct vm_area_struct *vma) { - if (vma->vm_mm == NULL) - return NULL; - - if (vma->vm_start == (long)vma->vm_mm->context.vdso) + if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso)) return "[vdso]"; - else - return NULL; + if (vma->vm_mm && (vma->vm_start == + (long)vma->vm_mm->context.vdso + PAGE_SIZE)) + return "[vdso_data]"; + return NULL; } diff --git a/arch/csky/kernel/vdso/.gitignore b/arch/csky/kernel/vdso/.gitignore new file mode 100644 index 0000000000000000000000000000000000000000..3a19def868eccd8c5544a6629592be0932204646 --- /dev/null +++ b/arch/csky/kernel/vdso/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +vdso.lds +*.tmp +vdso-syms.S diff --git a/arch/csky/kernel/vdso/Makefile b/arch/csky/kernel/vdso/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..13ac549c6587df60ce56c8616e05b8bd83a39ae3 --- /dev/null +++ b/arch/csky/kernel/vdso/Makefile @@ -0,0 +1,67 @@ +# SPDX-License-Identifier: GPL-2.0-only + +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_CKCORE_ADDR32|R_CKCORE_JUMP_SLOT +include $(srctree)/lib/vdso/Makefile + +# Symbols present in the vdso +vdso-syms = rt_sigreturn + +# Files to link into the vdso +obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o + +ccflags-y := -fno-stack-protector + +# Build rules +targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o +obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) + +obj-y += vdso.o vdso-syms.o +CPPFLAGS_vdso.lds += -P -C -U$(ARCH) + +# Disable gcov profiling for VDSO code +GCOV_PROFILE := n +KCOV_INSTRUMENT := n + +# Force dependency +$(obj)/vdso.o: $(obj)/vdso.so + +SYSCFLAGS_vdso.so.dbg = $(c_flags) +$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE + $(call if_changed,vdsold) +SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \ + -Wl,--build-id=sha1 -Wl,--hash-style=both + +$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE + $(call if_changed,so2s) + +# strip rule for the .so file +$(obj)/%.so: OBJCOPYFLAGS := -S +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +# actual build commands +# The DSO images are built using a special linker script +# Make sure only to export the intended __vdso_xxx symbol offsets. +quiet_cmd_vdsold = VDSOLD $@ + cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \ + -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \ + $(CROSS_COMPILE)objcopy \ + $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \ + rm $@.tmp + +# Extracts symbol offsets from the VDSO, converting them into an assembly file +# that contains the same symbols at the same offsets. +quiet_cmd_so2s = SO2S $@ + cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@ + +# install commands for the unstripped file +quiet_cmd_vdso_install = INSTALL $@ + cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ + +vdso.so: $(obj)/vdso.so.dbg + @mkdir -p $(MODLIB)/vdso + $(call cmd,vdso_install) + +vdso_install: vdso.so diff --git a/arch/csky/kernel/vdso/note.S b/arch/csky/kernel/vdso/note.S new file mode 100644 index 0000000000000000000000000000000000000000..2a956c942211140ea137a7203142d54d07144078 --- /dev/null +++ b/arch/csky/kernel/vdso/note.S @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include +#include + +ELFNOTE_START(Linux, 0, "a") + .long LINUX_VERSION_CODE +ELFNOTE_END diff --git a/arch/csky/kernel/vdso/rt_sigreturn.S b/arch/csky/kernel/vdso/rt_sigreturn.S new file mode 100644 index 0000000000000000000000000000000000000000..0a6bd1216118c184bf6153255886e0cee6fe6fc6 --- /dev/null +++ b/arch/csky/kernel/vdso/rt_sigreturn.S @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include +#include +#include + + .text +ENTRY(__vdso_rt_sigreturn) + .cfi_startproc + .cfi_signal_frame + SET_SYSCALL_ID + trap 0 + .cfi_endproc +ENDPROC(__vdso_rt_sigreturn) diff --git a/arch/csky/kernel/vdso/so2s.sh b/arch/csky/kernel/vdso/so2s.sh new file mode 100755 index 0000000000000000000000000000000000000000..69da3d529c6da36b80981c508842a1165aa83a5f --- /dev/null +++ b/arch/csky/kernel/vdso/so2s.sh @@ -0,0 +1,5 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ + +sed 's!\([0-9a-f]*\) T \([a-z0-9_]*\)\(@@LINUX_5.10\)*!.global \2\n.set \2,0x\1!' \ +| grep '^\.' diff --git a/arch/csky/kernel/vdso/vdso.S b/arch/csky/kernel/vdso/vdso.S new file mode 100644 index 0000000000000000000000000000000000000000..5162ca0694949a38e19b05d964eb58946871c898 --- /dev/null +++ b/arch/csky/kernel/vdso/vdso.S @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include +#include +#include + + __PAGE_ALIGNED_DATA + + .globl vdso_start, vdso_end + .balign PAGE_SIZE +vdso_start: + .incbin "arch/csky/kernel/vdso/vdso.so" + .balign PAGE_SIZE +vdso_end: + + .previous diff --git a/arch/csky/kernel/vdso/vdso.lds.S b/arch/csky/kernel/vdso/vdso.lds.S new file mode 100644 index 0000000000000000000000000000000000000000..8d226252d4394e4e2aed1cb7444b329c75eca386 --- /dev/null +++ b/arch/csky/kernel/vdso/vdso.lds.S @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include + +OUTPUT_ARCH(csky) + +SECTIONS +{ + PROVIDE(_vdso_data = . + PAGE_SIZE); + . = SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .note : { *(.note.*) } :text :note + .dynamic : { *(.dynamic) } :text :dynamic + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) } + + . = 0x800; + .text : { *(.text .text.*) } :text + + .data : { + *(.got.plt) *(.got) + *(.data .data.* .gnu.linkonce.d.*) + *(.dynbss) + *(.bss .bss.* .gnu.linkonce.b.*) + } +} + +PHDRS +{ + text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ + eh_frame_hdr PT_GNU_EH_FRAME; +} + +VERSION +{ + LINUX_5.10 { + global: + __vdso_rt_sigreturn; + local: *; + }; +}