diff options
author | dchagin <dchagin@FreeBSD.org> | 2016-01-09 15:44:38 +0000 |
---|---|---|
committer | dchagin <dchagin@FreeBSD.org> | 2016-01-09 15:44:38 +0000 |
commit | 18c167233413ace7a8a90b3291ccd255ba510cc4 (patch) | |
tree | 2dd502aaab8976e7184c48db61fddd6e98e59a43 /sys/i386/linux | |
parent | 2e9cc3f70d31eef39a4b3f238bb4d7324769d0c4 (diff) | |
download | FreeBSD-src-18c167233413ace7a8a90b3291ccd255ba510cc4.zip FreeBSD-src-18c167233413ace7a8a90b3291ccd255ba510cc4.tar.gz |
MFC r283407:
Implement vdso - virtual dynamic shared object. Through vdso Linux
exposes functions from kernel with proper DWARF CFI information so that
it becomes easier to unwind through them.
Using vdso is a mandatory for a thread cancelation && cleanup
on a modern glibc.
Diffstat (limited to 'sys/i386/linux')
-rw-r--r-- | sys/i386/linux/linux.h | 2 | ||||
-rw-r--r-- | sys/i386/linux/linux_genassym.c | 3 | ||||
-rw-r--r-- | sys/i386/linux/linux_locore.s | 154 | ||||
-rw-r--r-- | sys/i386/linux/linux_sysvec.c | 65 | ||||
-rw-r--r-- | sys/i386/linux/linux_vdso.lds.s | 65 |
5 files changed, 256 insertions, 33 deletions
diff --git a/sys/i386/linux/linux.h b/sys/i386/linux/linux.h index 6a20a68..251c64e 100644 --- a/sys/i386/linux/linux.h +++ b/sys/i386/linux/linux.h @@ -108,7 +108,7 @@ typedef struct { /* * Miscellaneous */ -#define LINUX_AT_COUNT 16 /* Count of used aux entry types. +#define LINUX_AT_COUNT 18 /* Count of used aux entry types. * Keep this synchronized with * elf_linux_fixup() code. */ diff --git a/sys/i386/linux/linux_genassym.c b/sys/i386/linux/linux_genassym.c index 1e84572..9735110 100644 --- a/sys/i386/linux/linux_genassym.c +++ b/sys/i386/linux/linux_genassym.c @@ -6,6 +6,7 @@ __FBSDID("$FreeBSD$"); #include <sys/systm.h> #include <i386/linux/linux.h> +#include <compat/linux/linux_mib.h> ASSYM(LINUX_SIGF_HANDLER, offsetof(struct l_sigframe, sf_handler)); ASSYM(LINUX_SIGF_SC, offsetof(struct l_sigframe, sf_sc)); @@ -14,3 +15,5 @@ ASSYM(LINUX_SC_EFLAGS, offsetof(struct l_sigcontext, sc_eflags)); ASSYM(LINUX_RT_SIGF_HANDLER, offsetof(struct l_rt_sigframe, sf_handler)); ASSYM(LINUX_RT_SIGF_UC, offsetof(struct l_rt_sigframe, sf_sc)); ASSYM(LINUX_RT_SIGF_SC, offsetof(struct l_ucontext, uc_mcontext)); +ASSYM(LINUX_SC_ESP, offsetof(struct l_sigcontext, sc_esp)); +ASSYM(LINUX_VERSION_CODE, LINUX_VERSION_CODE); diff --git a/sys/i386/linux/linux_locore.s b/sys/i386/linux/linux_locore.s index a3e0e7dc..54553b5 100644 --- a/sys/i386/linux/linux_locore.s +++ b/sys/i386/linux/linux_locore.s @@ -5,33 +5,145 @@ #include <i386/linux/linux_syscall.h> /* system call numbers */ +#include "assym.s" + +/* + * To avoid excess stack frame the signal trampoline code emulates + * the 'call' instruction. + */ NON_GPROF_ENTRY(linux_sigcode) - call *LINUX_SIGF_HANDLER(%esp) - leal LINUX_SIGF_SC(%esp),%ebx /* linux scp */ - mov LINUX_SC_GS(%ebx),%gs - movl %esp, %ebx /* pass sigframe */ - push %eax /* fake ret addr */ + movl %esp, %ebx /* preserve sigframe */ + call .getip0 +.getip0: + popl %eax + add $.startsigcode-.getip0, %eax /* ret address */ + push %eax + jmp *LINUX_SIGF_HANDLER(%ebx) +.startsigcode: + popl %eax /* gcc unwind code need this */ movl $LINUX_SYS_linux_sigreturn,%eax /* linux_sigreturn() */ int $0x80 /* enter kernel with args */ +.endsigcode: 0: jmp 0b - ALIGN_TEXT -/* XXXXX */ -linux_rt_sigcode: - call *LINUX_RT_SIGF_HANDLER(%esp) + +NON_GPROF_ENTRY(linux_rt_sigcode) leal LINUX_RT_SIGF_UC(%esp),%ebx /* linux ucp */ leal LINUX_RT_SIGF_SC(%ebx),%ecx /* linux sigcontext */ - mov LINUX_SC_GS(%ecx),%gs - push %eax /* fake ret addr */ + movl %esp, %edi + call .getip1 +.getip1: + popl %eax + add $.startrtsigcode-.getip1, %eax /* ret address */ + push %eax + jmp *LINUX_RT_SIGF_HANDLER(%edi) +.startrtsigcode: movl $LINUX_SYS_linux_rt_sigreturn,%eax /* linux_rt_sigreturn() */ int $0x80 /* enter kernel with args */ +.endrtsigcode: 0: jmp 0b - ALIGN_TEXT -/* XXXXX */ -linux_esigcode: - - .data - .globl linux_szsigcode, linux_sznonrtsigcode -linux_szsigcode: - .long linux_esigcode-linux_sigcode -linux_sznonrtsigcode: - .long linux_rt_sigcode-linux_sigcode + +NON_GPROF_ENTRY(linux_vsyscall) +.startvsyscall: + int $0x80 + ret +.endvsyscall: + + + .section .note.Linux, "a",@note + .long 2f - 1f /* namesz */ + .balign 4 + .long 4f - 3f /* descsz */ + .long 0 +1: + .asciz "Linux" +2: + .balign 4 +3: + .long LINUX_VERSION_CODE +4: + .balign 4 + .previous + + +#define do_cfa_expr(offset) \ + .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ + .uleb128 11f-10f; /* length */ \ +10: .byte 0x74; /* DW_OP_breg4 */ \ + .sleb128 offset; /* offset */ \ + .byte 0x06; /* DW_OP_deref */ \ +11: + + + /* CIE */ + .section .eh_frame,"a",@progbits +.LSTARTFRAMEDLSI1: + .long .LENDCIEDLSI1-.LSTARTCIEDLSI1 +.LSTARTCIEDLSI1: + .long 0 /* CIE ID */ + .byte 1 /* Version number */ + .string "zRS" /* NULL-terminated + * augmentation string + */ + .uleb128 1 /* Code alignment factor */ + .sleb128 -4 /* Data alignment factor */ + .byte 8 /* Return address + * register column + */ + .uleb128 1 /* Augmentation value length */ + .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */ + .byte 0 /* DW_CFA_nop */ + .align 4 +.LENDCIEDLSI1: + + /* FDE */ + .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */ +.LSTARTFDEDLSI1: + .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */ + .long .startsigcode-. /* PC-relative start address */ + .long .endsigcode-.startsigcode + .uleb128 0 /* Augmentation */ + do_cfa_expr(LINUX_SIGF_SC-8) + .align 4 +.LENDFDEDLSI1: + + .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */ +.LSTARTFDEDLSI2: + .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */ + .long .startrtsigcode-. /* PC-relative start address */ + .long .endrtsigcode-.startrtsigcode + .uleb128 0 /* Augmentation */ + do_cfa_expr(LINUX_RT_SIGF_SC-4+LINUX_SC_ESP) + .align 4 +.LENDFDEDLSI2: + .previous + + .section .eh_frame,"a",@progbits +.LSTARTFRAMEDLSI2: + .long .LENDCIEDLSI2-.LSTARTCIEDLSI2 +.LSTARTCIEDLSI2: + .long 0 /* CIE ID */ + .byte 1 /* Version number */ + .string "zR" /* NULL-terminated + * augmentation string + */ + .uleb128 1 /* Code alignment factor */ + .sleb128 -4 /* Data alignment factor */ + .byte 8 /* Return address register column */ + .uleb128 1 /* Augmentation value length */ + .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */ + .byte 0x0c /* DW_CFA_def_cfa */ + .uleb128 4 + .uleb128 4 + .byte 0x88 /* DW_CFA_offset, column 0x8 */ + .uleb128 1 + .align 4 +.LENDCIEDLSI2: + .long .LENDFDEDLSI3-.LSTARTFDEDLSI3 /* Length FDE */ +.LSTARTFDEDLSI3: + .long .LSTARTFDEDLSI3-.LSTARTFRAMEDLSI2 /* CIE pointer */ + .long .startvsyscall-. /* PC-relative start address */ + .long .endvsyscall-.startvsyscall + .uleb128 0 + .align 4 +.LENDFDEDLSI3: + .previous diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c index 970bd05..730e7ef 100644 --- a/sys/i386/linux/linux_sysvec.c +++ b/sys/i386/linux/linux_sysvec.c @@ -71,6 +71,7 @@ __FBSDID("$FreeBSD$"); #include <compat/linux/linux_misc.h> #include <compat/linux/linux_signal.h> #include <compat/linux/linux_util.h> +#include <compat/linux/linux_vdso.h> MODULE_VERSION(linux, 1); @@ -93,8 +94,11 @@ MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures"); #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings)) -extern char linux_sigcode[]; -extern int linux_szsigcode; +static int linux_szsigcode; +static vm_object_t linux_shared_page_obj; +static char *linux_shared_page_mapping; +extern char _binary_linux_locore_o_start; +extern char _binary_linux_locore_o_end; extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; @@ -110,6 +114,8 @@ static void exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack); static register_t *linux_copyout_strings(struct image_params *imgp); static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel); +static void linux_vdso_install(void *param); +static void linux_vdso_deinstall(void *param); static int linux_szplatform; const char *linux_platform; @@ -199,6 +205,10 @@ static int _bsd_to_linux_trapcode[] = { _bsd_to_linux_trapcode[(code)]: \ LINUX_T_UNKNOWN) +LINUX_VDSO_SYM_INTPTR(linux_sigcode); +LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); +LINUX_VDSO_SYM_INTPTR(linux_vsyscall); + /* * If FreeBSD & Linux have a difference of opinion about what a trap * means, deal with it here. @@ -255,6 +265,9 @@ elf_linux_fixup(register_t **stack_base, struct image_params *imgp) args = (Elf32_Auxargs *)imgp->auxargs; pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2); + AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, + imgp->proc->p_sysent->sv_shared_page_base); + AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall); AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); /* @@ -399,10 +412,6 @@ linux_copyout_strings(struct image_params *imgp) return (stack_base); } - - -extern unsigned long linux_sznonrtsigcode; - static void linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) { @@ -478,6 +487,7 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi; frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp; frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx; + frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp; frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx; frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx; frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax; @@ -515,7 +525,7 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) * Build context to run handler in. */ regs->tf_esp = (int)fp; - regs->tf_eip = p->p_sysent->sv_sigcode_base + linux_sznonrtsigcode; + regs->tf_eip = linux_rt_sigcode; regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; @@ -606,6 +616,7 @@ linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) frame.sf_sc.sc_esi = regs->tf_esi; frame.sf_sc.sc_ebp = regs->tf_ebp; frame.sf_sc.sc_ebx = regs->tf_ebx; + frame.sf_sc.sc_esp = regs->tf_esp; frame.sf_sc.sc_edx = regs->tf_edx; frame.sf_sc.sc_ecx = regs->tf_ecx; frame.sf_sc.sc_eax = regs->tf_eax; @@ -634,7 +645,7 @@ linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) * Build context to run handler in. */ regs->tf_esp = (int)fp; - regs->tf_eip = p->p_sysent->sv_sigcode_base; + regs->tf_eip = linux_sigcode; regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; @@ -950,7 +961,7 @@ struct sysentvec linux_sysvec = { .sv_transtrap = translate_traps, .sv_fixup = linux_fixup, .sv_sendsig = linux_sendsig, - .sv_sigcode = linux_sigcode, + .sv_sigcode = &_binary_linux_locore_o_start, .sv_szsigcode = &linux_szsigcode, .sv_prepsyscall = NULL, .sv_name = "Linux a.out", @@ -989,7 +1000,7 @@ struct sysentvec elf_linux_sysvec = { .sv_transtrap = translate_traps, .sv_fixup = elf_linux_fixup, .sv_sendsig = linux_sendsig, - .sv_sigcode = linux_sigcode, + .sv_sigcode = &_binary_linux_locore_o_start, .sv_szsigcode = &linux_szsigcode, .sv_prepsyscall = NULL, .sv_name = "Linux ELF", @@ -1015,7 +1026,39 @@ struct sysentvec elf_linux_sysvec = { .sv_schedtail = linux_schedtail, .sv_thread_detach = linux_thread_detach, }; -INIT_SYSENTVEC(elf_sysvec, &elf_linux_sysvec); + +static void +linux_vdso_install(void *param) +{ + + linux_szsigcode = (&_binary_linux_locore_o_end - + &_binary_linux_locore_o_start); + + if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) + panic("Linux invalid vdso size\n"); + + __elfN(linux_vdso_fixup)(&elf_linux_sysvec); + + linux_shared_page_obj = __elfN(linux_shared_page_init) + (&linux_shared_page_mapping); + + __elfN(linux_vdso_reloc)(&elf_linux_sysvec, LINUX_SHAREDPAGE); + + bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping, + linux_szsigcode); + elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; +} +SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, + (sysinit_cfunc_t)linux_vdso_install, NULL); + +static void +linux_vdso_deinstall(void *param) +{ + + __elfN(linux_shared_page_fini)(linux_shared_page_obj); +}; +SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, + (sysinit_cfunc_t)linux_vdso_deinstall, NULL); static char GNU_ABI_VENDOR[] = "GNU"; static int GNULINUX_ABI_DESC = 0; diff --git a/sys/i386/linux/linux_vdso.lds.s b/sys/i386/linux/linux_vdso.lds.s new file mode 100644 index 0000000..dcb61cf --- /dev/null +++ b/sys/i386/linux/linux_vdso.lds.s @@ -0,0 +1,65 @@ +/* + * Linker script for 32-bit vDSO. + * Copied from Linux kernel arch/x86/vdso/vdso-layout.lds.S + * and arch/x86/vdso/vdso32/vdso32.lds.S + * + * $FreeBSD$ + */ + +SECTIONS +{ + . = . + 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 + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { *(.rodata*) } :text + .data : { + *(.data*) + *(.sdata*) + *(.got.plt) *(.got) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + } + + .altinstructions : { *(.altinstructions) } + .altinstr_replacement : { *(.altinstr_replacement) } + + . = ALIGN(0x100); + .text : { *(.text*) } :text =0x90909090 +} + +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; +} + +ENTRY(linux_vsyscall); + +VERSION +{ + LINUX_2.5 { + global: + linux_vsyscall; + linux_sigcode; + linux_rt_sigcode; + local: *; + }; +} |