From a9f495b93f1497ced94dbe51ebb733537e0fa1ab Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 6 Jul 2021 09:55:12 -0700 Subject: [PATCH] linux-user/arm: Add vdso Signed-off-by: Richard Henderson --- linux-user/arm/Makefile.vdso | 17 ++++ linux-user/arm/meson.build | 12 +++ linux-user/arm/signal.c | 49 +++++---- linux-user/arm/vdso-asmoffset.h | 3 + linux-user/arm/vdso-be.so | Bin 0 -> 2648 bytes linux-user/arm/vdso-le.so | Bin 0 -> 2648 bytes linux-user/arm/vdso.S | 174 ++++++++++++++++++++++++++++++++ linux-user/arm/vdso.ld | 67 ++++++++++++ linux-user/elfload.c | 3 +- 9 files changed, 307 insertions(+), 18 deletions(-) create mode 100644 linux-user/arm/Makefile.vdso create mode 100644 linux-user/arm/vdso-asmoffset.h create mode 100755 linux-user/arm/vdso-be.so create mode 100755 linux-user/arm/vdso-le.so create mode 100644 linux-user/arm/vdso.S create mode 100644 linux-user/arm/vdso.ld diff --git a/linux-user/arm/Makefile.vdso b/linux-user/arm/Makefile.vdso new file mode 100644 index 0000000000..2d098a5748 --- /dev/null +++ b/linux-user/arm/Makefile.vdso @@ -0,0 +1,17 @@ +include $(BUILD_DIR)/tests/tcg/arm-linux-user/config-target.mak + +SUBDIR = $(SRC_PATH)/linux-user/arm +VPATH += $(SUBDIR) + +all: $(SUBDIR)/vdso-be.so $(SUBDIR)/vdso-le.so + +# Adding -use-blx disables unneeded interworking without actually using blx. +LDFLAGS = -nostdlib -shared -Wl,-use-blx \ + -Wl,-h,linux-vdso.so.1 -Wl,--build-id=sha1 \ + -Wl,--hash-style=both -Wl,-T,$(SUBDIR)/vdso.ld + +$(SUBDIR)/vdso-be.so: vdso.S vdso.ld vdso-asmoffset.h + $(CC) -o $@ $(LDFLAGS) -mbig-endian $< + +$(SUBDIR)/vdso-le.so: vdso.S vdso.ld vdso-asmoffset.h + $(CC) -o $@ $(LDFLAGS) -mlittle-endian $< diff --git a/linux-user/arm/meson.build b/linux-user/arm/meson.build index 5a93c925cf..c4bb9af5b8 100644 --- a/linux-user/arm/meson.build +++ b/linux-user/arm/meson.build @@ -5,3 +5,15 @@ syscall_nr_generators += { arguments: [ meson.current_source_dir() / 'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ], output: '@BASENAME@_nr.h') } + +# TARGET_BIG_ENDIAN is defined to 'n' for little-endian; which means it +# is always true as far as source_set.apply() is concerned. Always build +# both header files and include the right one via #if. + +vdso_be_inc = gen_vdso.process('vdso-be.so', + extra_args: ['-s', 'sigreturn_codes']) + +vdso_le_inc = gen_vdso.process('vdso-le.so', + extra_args: ['-s', 'sigreturn_codes']) + +linux_user_ss.add(when: 'TARGET_ARM', if_true: [vdso_be_inc, vdso_le_inc]) diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c index cf99fd7b8a..e19b514f17 100644 --- a/linux-user/arm/signal.c +++ b/linux-user/arm/signal.c @@ -21,6 +21,7 @@ #include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" +#include "vdso-asmoffset.h" struct target_sigcontext { abi_ulong trap_no; @@ -102,6 +103,11 @@ struct rt_sigframe struct sigframe sig; }; +QEMU_BUILD_BUG_ON(offsetof(struct sigframe, retcode[3]) + != SIGFRAME_RC3_OFFSET); +QEMU_BUILD_BUG_ON(offsetof(struct rt_sigframe, sig.retcode[3]) + != RT_SIGFRAME_RC3_OFFSET); + static abi_ptr sigreturn_fdpic_tramp; /* @@ -160,6 +166,9 @@ get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize) return (sp - framesize) & ~7; } +static void write_arm_sigreturn(uint32_t *rc, int syscall); +static void write_arm_fdpic_sigreturn(uint32_t *rc, int ofs); + static int setup_return(CPUARMState *env, struct target_sigaction *ka, int usig, struct sigframe *frame, abi_ulong sp_addr) @@ -167,9 +176,9 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, int usig, abi_ulong handler = 0; abi_ulong handler_fdpic_GOT = 0; abi_ulong retcode; - int thumb, retcode_idx; - int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); - bool copy_retcode; + bool is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); + bool is_rt = ka->sa_flags & TARGET_SA_SIGINFO; + bool thumb; if (is_fdpic) { /* In FDPIC mode, ka->_sa_handler points to a function @@ -184,9 +193,7 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, int usig, } else { handler = ka->_sa_handler; } - thumb = handler & 1; - retcode_idx = thumb + (ka->sa_flags & TARGET_SA_SIGINFO ? 2 : 0); uint32_t cpsr = cpsr_read(env); @@ -202,24 +209,32 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, int usig, cpsr &= ~CPSR_E; } + /* Our vdso default_sigreturn label is a table of entry points. */ + retcode = default_sigreturn + (is_fdpic * 2 + is_rt) * 8; + + /* + * Put the sigreturn code on the stack no matter which return + * mechanism we use in order to remain ABI compliant. + * Because this is about ABI, always use the A32 instructions, + * despite the fact that our actual vdso trampoline is T16. + */ + if (is_fdpic) { + write_arm_fdpic_sigreturn(frame->retcode, + is_rt ? RT_SIGFRAME_RC3_OFFSET + : SIGFRAME_RC3_OFFSET); + } else { + write_arm_sigreturn(frame->retcode, + is_rt ? TARGET_NR_rt_sigreturn + : TARGET_NR_sigreturn); + } + if (ka->sa_flags & TARGET_SA_RESTORER) { if (is_fdpic) { + /* Place the function descriptor in slot 3. */ __put_user((abi_ulong)ka->sa_restorer, &frame->retcode[3]); - retcode = (sigreturn_fdpic_tramp + - retcode_idx * RETCODE_BYTES + thumb); - copy_retcode = true; } else { retcode = ka->sa_restorer; - copy_retcode = false; } - } else { - retcode = default_sigreturn + retcode_idx * RETCODE_BYTES + thumb; - copy_retcode = true; - } - - /* Copy the code to the stack slot for ABI compatibility. */ - if (copy_retcode) { - memcpy(frame->retcode, g2h_untagged(retcode & ~1), RETCODE_BYTES); } env->regs[0] = usig; diff --git a/linux-user/arm/vdso-asmoffset.h b/linux-user/arm/vdso-asmoffset.h new file mode 100644 index 0000000000..252a95c46e --- /dev/null +++ b/linux-user/arm/vdso-asmoffset.h @@ -0,0 +1,3 @@ +/* offsetof(struct sigframe, retcode[3]) */ +#define SIGFRAME_RC3_OFFSET 756 +#define RT_SIGFRAME_RC3_OFFSET 884 diff --git a/linux-user/arm/vdso-be.so b/linux-user/arm/vdso-be.so new file mode 100755 index 0000000000000000000000000000000000000000..69cafbb956e283e2975bac59a10491c0cbafca57 GIT binary patch literal 2648 zcmbtWO>9(E6#nj;H$N@yFeL`XVS%x+1my)ugBXo*`ZH5ZTd=gTYT{!$^V*r%&TD2~ zYim%8VnIRJbRjXs8r^Cd0|^^qHyXo2UASPO;-YShF&O_?sLy=&-P^tyx-jv)oZNfP zJ@@b2bH4Ll>Fv)7LtvdE*bP7{I)V5~bin{Ru?tb`MjKK9VxVS&mjTHpAX(2>WG+K8 z;%dYIa4W2d6Fm7!ydJwQ)pY7KnZU-cX$L|0T$qkO+@~>xm|J-@u-7i1I zcU{Bjhu^k8*aaX7U?e!NSabb`D93@t)w>izbM~oil{eZOQN4h zQT5h*4^6b;`;nv39j3P7oajpW8cO@l54B$Ts=Lzt{*L=T+j9oCJzK1~c45*jJa11p zo>!i7HdP+zyiHwoYFejey5q(CJSNMPnYq1O*Q&YJgXljrI5KMQw+_f-8tb13zSf^V zc@L0pzEizxa03G(^3lv6YK$cPB+`*b06Y%HB*Z9yQ9z6Vm-zwFvx)u~ zfG-#mA$#T>_dE*Y_*QOuY$0`G>#NDvT2HpTzGbobRMY9i8}T<|XQF4#w<70^^C}s+ z|DymF0c=Mu`MuIJ7d{7Y5{$c4GWybQ(O4|i6lZ&{$yAp%KLMa$5`j%j*~GMsq=n0V zN8%yeSh&jG(t58+^#(gQwwl%73mv$@{)ei)`cBKW3)xieTh(R&+?jXsV`UkSt^aq3nnCf(lQbYrv;!13oP_;M2uAd@2;4na<5;E0&9P z5A8+RJx>p21`c(jR-ULj-b}S(7u=#mgWTYV-P>nphcW}bc3;mB>|Fohu1vpuIGa7% zJ8TbUy83(V5F{u7ssoTlPznJ}9Z+q8NfN(c)#j(X{1~j7R}I>d?p0jRfmNKZ!7ApxJgkYzj8)3lN`c<12AWx?S}VJiI>9c&a!U4iH9zIprDAnMg5^1L9<0pJ zfR*>WYI$tNb87lQ{u`wOY?HCCYbEQXCS3#W3DpK&lUa{dj7vMl_Z}5zMo<@JE)kz- z$5`ch%$NO2W*S~sF%^z)+L4(H%rmaH7BGmZ;TlD|gRburzl|UtWlj3n*^^?hHhcS+?i&!^WTR*;|4HJpqjlxHK2tNYSU{j;@TMjd4 z=FFM7Gv|C~U+Ejn3L#(+!7doB1Hf_v01L4WY)1^c(1JALfSltz<+7G2AjPaVxEzHP zx&j0&0Cz*O2uLyOM}F~(cP+q3FCfLtv;8(CZGe>U`~v_Y0Q!f=@XmqCS6$!T=)JLH z>#rXkyVvqqLM*2MjOp|KEP%iM3B0rg#JHCQ`Hk}e*aW}>uo*xaz`Y>wu3Nz0LE!N_ zZU=$)DLelY8SWDW8UbuU0($|tQMEtytpJ`6>Ad5^A>9q_--4BZ_iMm=;G3}}cuxes zm43p>bTjuoV&EI)bq{NQCt3mCyf3 z^35O7?@Fj|6Sy<`afEY(xhK&YIq(c1V{%*o;{YZE@FIX|0h|XgCsb^o62NT$O9E)* zm;m+&6%T|sk%M(IC0Y|n8Fvrq*k7ZAAsMW-ZVTu0N{rW#*YK|8Y(7? zJ@btaCvrz%oowc&#~0J5n_o@6mOPVqee>B(=bFwpzR~bz{6g%l=-ZKt)+OEp_wNF5 z7Lc)o{?tz#-wxnQ0A~Os=s2BGs-tiJR|c)BQi{HuE5WyqljWLnIl49ixa_ zO+5O2ASVzJ`SOZml&&J2`K)x63E!{kDkI1PYFp zH_4X#rF0ny=+X%ok!%8t=tPXDn_oo)N&N*1QLF@f8)MIxYNl=yTKhAg{g%-83#Y~JLSH_r2by63IAU)Fm`^(jyym~m_zA1 zAx>#KG7j@yigBjzm>^$ARJoGie=OD=1LK-4&t`Bn3M>mq{@{NKo{#TF#xi$6l;XfA SW|2M<(Nbska09Tkf!)7C+HF(- literal 0 HcmV?d00001 diff --git a/linux-user/arm/vdso.S b/linux-user/arm/vdso.S new file mode 100644 index 0000000000..b3bb6491dc --- /dev/null +++ b/linux-user/arm/vdso.S @@ -0,0 +1,174 @@ +/* + * arm linux replacement vdso. + * + * Copyright 2023 Linaro, Ltd. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include +#include "vdso-asmoffset.h" + +/* + * All supported cpus have T16 instructions: at least arm4t. + * + * We support user-user with m-profile cpus as an extension, because it + * is useful for testing gcc, which requires we avoid A32 instructions. + */ + .thumb + .arch armv4t + .eabi_attribute Tag_FP_arch, 0 + .eabi_attribute Tag_ARM_ISA_use, 0 + + .text + +.macro raw_syscall n + .ifne \n < 0x100 + mov r7, #\n + .elseif \n < 0x1ff + mov r7, #0xff + add r7, #(\n - 0xff) + .else + .err + .endif + swi #0 +.endm + +.macro fdpic_thunk ofs + ldr r3, [sp, #\ofs] + ldmia r2, {r2, r3} + mov r9, r3 + bx r2 +.endm + +.macro endf name + .globl \name + .type \name, %function + .size \name, . - \name +.endm + +/* + * We must save/restore r7 for the EABI syscall number. + * While we're doing that, we might as well save LR to get a free return, + * and a branch that is interworking back to ARMv5. + */ + +.macro SYSCALL name, nr +\name: + .cfi_startproc + push {r7, lr} + .cfi_adjust_cfa_offset 8 + .cfi_offset r7, -8 + .cfi_offset lr, -4 + raw_syscall \nr + pop {r7, pc} + .cfi_endproc +endf \name +.endm + +SYSCALL __vdso_clock_gettime, __NR_clock_gettime +SYSCALL __vdso_clock_gettime64, __NR_clock_gettime64 +SYSCALL __vdso_clock_getres, __NR_clock_getres +SYSCALL __vdso_gettimeofday, __NR_gettimeofday + + +/* + * We, like the real kernel, use a table of sigreturn trampolines. + * Unlike the real kernel, we do not attempt to pack this into as + * few bytes as possible -- simply use 8 bytes per slot. + * + * Within each slot, use the exact same code sequence as the kernel, + * lest we trip up someone doing code inspection. + */ + +.macro slot n + .balign 8 + .org sigreturn_codes + 8 * \n +.endm + +.macro cfi_fdpic_r9 ofs + /* + * fd = *(r13 + ofs) + * r9 = *(fd + 4) + * + * DW_CFA_expression r9, length (7), + * DW_OP_breg13, ofs, DW_OP_deref, + * DW_OP_plus_uconst, 4, DW_OP_deref + */ + .cfi_escape 0x10, 9, 7, 0x7d, (\ofs & 0x7f) + 0x80, (\ofs >> 7), 0x06, 0x23, 4, 0x06 +.endm + +.macro cfi_fdpic_pc ofs + /* + * fd = *(r13 + ofs) + * pc = *fd + * + * DW_CFA_expression lr (14), length (5), + * DW_OP_breg13, ofs, DW_OP_deref, DW_OP_deref + */ + .cfi_escape 0x10, 14, 5, 0x7d, (\ofs & 0x7f) + 0x80, (\ofs >> 7), 0x06, 0x06 +.endm + +/* + * Start the unwind info at least one instruction before the signal + * trampoline, because the unwinder will assume we are returning + * after a call site. + */ + .cfi_startproc simple + .cfi_signal_frame + .cfi_return_column 15 + + .cfi_def_cfa sp, 32 + 64 + .cfi_offset r0, -16 * 4 + .cfi_offset r1, -15 * 4 + .cfi_offset r2, -14 * 4 + .cfi_offset r3, -13 * 4 + .cfi_offset r4, -12 * 4 + .cfi_offset r5, -11 * 4 + .cfi_offset r6, -10 * 4 + .cfi_offset r7, -9 * 4 + .cfi_offset r8, -8 * 4 + .cfi_offset r9, -7 * 4 + .cfi_offset r10, -6 * 4 + .cfi_offset r11, -5 * 4 + .cfi_offset r12, -4 * 4 + .cfi_offset r13, -3 * 4 + .cfi_offset r14, -2 * 4 + .cfi_offset r15, -1 * 4 + + nop + + .balign 16 +sigreturn_codes: + /* [EO]ABI sigreturn */ + slot 0 + raw_syscall __NR_sigreturn + + .cfi_def_cfa_offset 160 + 64 + + /* [EO]ABI rt_sigreturn */ + slot 1 + raw_syscall __NR_rt_sigreturn + + .cfi_endproc + + /* FDPIC sigreturn */ + .cfi_startproc + cfi_fdpic_pc SIGFRAME_RC3_OFFSET + cfi_fdpic_r9 SIGFRAME_RC3_OFFSET + + slot 2 + fdpic_thunk SIGFRAME_RC3_OFFSET + .cfi_endproc + + /* FDPIC rt_sigreturn */ + .cfi_startproc + cfi_fdpic_pc RT_SIGFRAME_RC3_OFFSET + cfi_fdpic_r9 RT_SIGFRAME_RC3_OFFSET + + slot 3 + fdpic_thunk RT_SIGFRAME_RC3_OFFSET + .cfi_endproc + + .balign 16 +endf sigreturn_codes diff --git a/linux-user/arm/vdso.ld b/linux-user/arm/vdso.ld new file mode 100644 index 0000000000..3b00adf27a --- /dev/null +++ b/linux-user/arm/vdso.ld @@ -0,0 +1,67 @@ +/* + * Linker script for linux arm replacement vdso. + * + * Copyright 2023 Linaro, Ltd. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +VERSION { + LINUX_2.6 { + global: + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_clock_getres; + __vdso_clock_gettime64; + + local: *; + }; +} + + +PHDRS { + phdr PT_PHDR FLAGS(4) PHDRS; + load PT_LOAD FLAGS(7) FILEHDR PHDRS; /* FLAGS=RWX */ + dynamic PT_DYNAMIC FLAGS(4); + eh_frame_hdr PT_GNU_EH_FRAME; + note PT_NOTE FLAGS(4); +} + +SECTIONS { + . = SIZEOF_HEADERS; + + /* + * The following, including the FILEHDRS and PHDRS, are modified + * when we relocate the binary. We want them to be initially + * writable for the relocation; we'll force them read-only after. + */ + .note : { *(.note*) } :load :note + .dynamic : { *(.dynamic) } :load :dynamic + .dynsym : { *(.dynsym) } :load + /* + * There ought not be any real read-write data. + * But since we manipulated the segment layout, + * we have to put these sections somewhere. + */ + .data : { + *(.data*) + *(.sdata*) + *(.got.plt) *(.got) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + } + + .rodata : { *(.rodata*) } + .hash : { *(.hash) } + .gnu.hash : { *(.gnu.hash) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + .eh_frame_hdr : { *(.eh_frame_hdr) } :load :eh_frame_hdr + .eh_frame : { *(.eh_frame) } :load + + .text : { *(.text*) } :load +} diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 0a3a57018b..7400ed0ca1 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -944,13 +944,14 @@ const char *elf_hwcap2_str(uint32_t bit) #undef GET_FEATURE_ID +#endif /* not TARGET_AARCH64 */ + #if TARGET_BIG_ENDIAN # define VDSO_HEADER "vdso-be.c.inc" #else # define VDSO_HEADER "vdso-le.c.inc" #endif -#endif /* not TARGET_AARCH64 */ #endif /* TARGET_ARM */ #ifdef TARGET_SPARC -- 2.50.1