| |
| /*--------------------------------------------------------------------*/ |
| /*--- Doing syscalls. m_syscall.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2008 Julian Seward |
| jseward@acm.org |
| |
| This program is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| #include "pub_core_basics.h" |
| #include "pub_core_vki.h" |
| #include "pub_core_vkiscnums.h" |
| #include "pub_core_syscall.h" |
| |
| /* --------------------------------------------------------------------- |
| Building syscall return values. |
| ------------------------------------------------------------------ */ |
| |
| /* Make a SysRes value from an syscall return value. This is |
| Linux-specific. |
| |
| From: |
| http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/sysdeps/unix/sysv/ |
| linux/i386/sysdep.h? |
| rev=1.28&content-type=text/x-cvsweb-markup&cvsroot=glibc |
| |
| Linux uses a negative return value to indicate syscall errors, |
| unlike most Unices, which use the condition codes' carry flag. |
| |
| Since version 2.1 the return value of a system call might be |
| negative even if the call succeeded. E.g., the 'lseek' system call |
| might return a large offset. Therefore we must not anymore test |
| for < 0, but test for a real error by making sure the value in %eax |
| is a real error number. Linus said he will make sure the no |
| syscall returns a value in -1 .. -4095 as a valid result so we can |
| safely test with -4095. |
| */ |
| SysRes VG_(mk_SysRes_x86_linux) ( UInt val ) { |
| SysRes res; |
| res.isError = val >= -4095 && val <= -1; |
| if (res.isError) { |
| res.err = -val; |
| res.res = 0; |
| } else { |
| res.err = 0; |
| res.res = val; |
| } |
| return res; |
| } |
| |
| /* Similarly .. */ |
| SysRes VG_(mk_SysRes_amd64_linux) ( ULong val ) { |
| SysRes res; |
| res.isError = val >= -4095 && val <= -1; |
| if (res.isError) { |
| res.err = -val; |
| res.res = 0; |
| } else { |
| res.err = 0; |
| res.res = val; |
| } |
| return res; |
| } |
| |
| /* PPC uses the CR7.SO bit to flag an error (CR0 in IBM-speak) */ |
| /* Note this must be in the bottom bit of the second arg */ |
| SysRes VG_(mk_SysRes_ppc32_linux) ( UInt val, UInt cr0so ) { |
| SysRes res; |
| res.isError = (cr0so & 1) != 0; |
| if (res.isError) { |
| res.err = val; |
| res.res = 0; |
| } else { |
| res.err = 0; |
| res.res = val; |
| } |
| return res; |
| } |
| |
| /* As per ppc32 version, cr0.so must be in l.s.b. of 2nd arg */ |
| SysRes VG_(mk_SysRes_ppc64_linux) ( ULong val, ULong cr0so ) { |
| SysRes res; |
| res.isError = (cr0so & 1) != 0; |
| if (res.isError) { |
| res.err = val; |
| res.res = 0; |
| } else { |
| res.err = 0; |
| res.res = val; |
| } |
| return res; |
| } |
| |
| /* AIX scheme: we have to record both 'res' (r3) and 'err' (r4). If |
| 'err' is nonzero then the call has failed, but it could still be |
| that AIX userspace will ignore 'err' and instead consult 'res' to |
| determine if the call failed. So we have to record both. */ |
| SysRes VG_(mk_SysRes_ppc32_aix5) ( UInt res, UInt err ) { |
| SysRes r; |
| r.res = res; |
| r.err = err; |
| r.isError = r.err != 0; |
| return r; |
| } |
| |
| SysRes VG_(mk_SysRes_ppc64_aix5) ( ULong res, ULong err ) { |
| SysRes r; |
| r.res = res; |
| r.err = err; |
| r.isError = r.err != 0; |
| return r; |
| } |
| |
| /* Generic constructors. */ |
| SysRes VG_(mk_SysRes_Error) ( UWord err ) { |
| SysRes r; |
| r.res = 0; |
| r.err = err; |
| r.isError = True; |
| return r; |
| } |
| |
| SysRes VG_(mk_SysRes_Success) ( UWord res ) { |
| SysRes r; |
| r.res = res; |
| r.err = 0; |
| r.isError = False; |
| return r; |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| A function for doing syscalls. |
| ------------------------------------------------------------------ */ |
| |
| #if defined(VGP_x86_linux) |
| /* Incoming args (syscall number + up to 6 args) come on the stack. |
| (ie. the C calling convention). |
| |
| The syscall number goes in %eax. The args are passed to the syscall in |
| the regs %ebx, %ecx, %edx, %esi, %edi, %ebp, ie. the kernel's syscall |
| calling convention. |
| |
| %eax gets the return value. Not sure which registers the kernel |
| clobbers, so we preserve all the callee-save regs (%esi, %edi, %ebx, |
| %ebp). |
| */ |
| extern UWord do_syscall_WRK ( |
| UWord syscall_no, |
| UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6 |
| ); |
| asm( |
| ".text\n" |
| "do_syscall_WRK:\n" |
| " push %esi\n" |
| " push %edi\n" |
| " push %ebx\n" |
| " push %ebp\n" |
| " movl 16+ 4(%esp),%eax\n" |
| " movl 16+ 8(%esp),%ebx\n" |
| " movl 16+12(%esp),%ecx\n" |
| " movl 16+16(%esp),%edx\n" |
| " movl 16+20(%esp),%esi\n" |
| " movl 16+24(%esp),%edi\n" |
| " movl 16+28(%esp),%ebp\n" |
| " int $0x80\n" |
| " popl %ebp\n" |
| " popl %ebx\n" |
| " popl %edi\n" |
| " popl %esi\n" |
| " ret\n" |
| ".previous\n" |
| ); |
| |
| #elif defined(VGP_amd64_linux) |
| /* Incoming args (syscall number + up to 6 args) come in %rdi, %rsi, |
| %rdx, %rcx, %r8, %r9, and the last one on the stack (ie. the C |
| calling convention). |
| |
| The syscall number goes in %rax. The args are passed to the syscall in |
| the regs %rdi, %rsi, %rdx, %r10, %r8, %r9 (yes, really %r10, not %rcx), |
| ie. the kernel's syscall calling convention. |
| |
| %rax gets the return value. %rcx and %r11 are clobbered by the syscall; |
| no matter, they are caller-save (the syscall clobbers no callee-save |
| regs, so we don't have to do any register saving/restoring). |
| */ |
| extern UWord do_syscall_WRK ( |
| UWord syscall_no, |
| UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6 |
| ); |
| asm( |
| ".text\n" |
| "do_syscall_WRK:\n" |
| /* Convert function calling convention --> syscall calling |
| convention */ |
| " movq %rdi, %rax\n" |
| " movq %rsi, %rdi\n" |
| " movq %rdx, %rsi\n" |
| " movq %rcx, %rdx\n" |
| " movq %r8, %r10\n" |
| " movq %r9, %r8\n" |
| " movq 8(%rsp), %r9\n" /* last arg from stack */ |
| " syscall\n" |
| " ret\n" |
| ".previous\n" |
| ); |
| |
| #elif defined(VGP_ppc32_linux) |
| /* Incoming args (syscall number + up to 6 args) come in %r3:%r9. |
| |
| The syscall number goes in %r0. The args are passed to the syscall in |
| the regs %r3:%r8, i.e. the kernel's syscall calling convention. |
| |
| The %cr0.so bit flags an error. |
| We return the syscall return value in %r3, and the %cr0.so in |
| the lowest bit of %r4. |
| We return a ULong, of which %r3 is the high word, and %r4 the low. |
| No callee-save regs are clobbered, so no saving/restoring is needed. |
| */ |
| extern ULong do_syscall_WRK ( |
| UWord syscall_no, |
| UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6 |
| ); |
| asm( |
| ".text\n" |
| "do_syscall_WRK:\n" |
| " mr 0,3\n" |
| " mr 3,4\n" |
| " mr 4,5\n" |
| " mr 5,6\n" |
| " mr 6,7\n" |
| " mr 7,8\n" |
| " mr 8,9\n" |
| " sc\n" /* syscall: sets %cr0.so on error */ |
| " mfcr 4\n" /* %cr -> low word of return var */ |
| " rlwinm 4,4,4,31,31\n" /* rotate flag bit so to lsb, and mask it */ |
| " blr\n" /* and return */ |
| ".previous\n" |
| ); |
| |
| #elif defined(VGP_ppc64_linux) |
| /* Due to the need to return 65 bits of result, this is completely |
| different from the ppc32 case. The single arg register points to a |
| 7-word block containing the syscall # and the 6 args. The syscall |
| result proper is put in [0] of the block, and %cr0.so is in the |
| bottom but of [1]. */ |
| extern void do_syscall_WRK ( ULong* argblock ); |
| asm( |
| ".align 2\n" |
| ".globl do_syscall_WRK\n" |
| ".section \".opd\",\"aw\"\n" |
| ".align 3\n" |
| "do_syscall_WRK:\n" |
| ".quad .do_syscall_WRK,.TOC.@tocbase,0\n" |
| ".previous\n" |
| ".type .do_syscall_WRK,@function\n" |
| ".globl .do_syscall_WRK\n" |
| ".do_syscall_WRK:\n" |
| " std 3,-16(1)\n" /* stash arg */ |
| " ld 8, 48(3)\n" /* sc arg 6 */ |
| " ld 7, 40(3)\n" /* sc arg 5 */ |
| " ld 6, 32(3)\n" /* sc arg 4 */ |
| " ld 5, 24(3)\n" /* sc arg 3 */ |
| " ld 4, 16(3)\n" /* sc arg 2 */ |
| " ld 0, 0(3)\n" /* sc number */ |
| " ld 3, 8(3)\n" /* sc arg 1 */ |
| " sc\n" /* result in r3 and cr0.so */ |
| " ld 5,-16(1)\n" /* reacquire argblock ptr (r5 is caller-save) */ |
| " std 3,0(5)\n" /* argblock[0] = r3 */ |
| " mfcr 3\n" |
| " srwi 3,3,28\n" |
| " andi. 3,3,1\n" |
| " std 3,8(5)\n" /* argblock[1] = cr0.s0 & 1 */ |
| " blr\n" |
| ); |
| |
| #elif defined(VGP_ppc32_aix5) |
| static void do_syscall_WRK ( UWord* res_r3, UWord* res_r4, |
| UWord sysno, |
| UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6, |
| UWord a7, UWord a8 ) |
| { |
| /* Syscalls on AIX are very similar to function calls: |
| - up to 8 args in r3-r10 |
| - syscall number in r2 |
| - kernel resumes at 'lr', so must set it appropriately beforehand |
| - r3 holds the result and r4 any applicable error code |
| See http://www.cs.utexas.edu/users/cart/publications/tr00-04.ps |
| and also 'man truss'. |
| */ |
| /* For some reason gcc-3.3.2 doesn't preserve r31 across the asm |
| even though we state it to be trashed. So use r27 instead. */ |
| UWord args[9]; |
| args[0] = sysno; |
| args[1] = a1; args[2] = a2; |
| args[3] = a3; args[4] = a4; |
| args[5] = a5; args[6] = a6; |
| args[7] = a7; args[8] = a8; |
| |
| __asm__ __volatile__( |
| |
| // establish base ptr |
| "mr 28,%0\n\t" |
| |
| // save r2, lr |
| "mr 27,2\n\t" // save r2 in r27 |
| "mflr 30\n\t" // save lr in r30 |
| |
| // set syscall number and args |
| "lwz 2, 0(28)\n\t" |
| "lwz 3, 4(28)\n\t" |
| "lwz 4, 8(28)\n\t" |
| "lwz 5, 12(28)\n\t" |
| "lwz 6, 16(28)\n\t" |
| "lwz 7, 20(28)\n\t" |
| "lwz 8, 24(28)\n\t" |
| "lwz 9, 28(28)\n\t" |
| "lwz 10, 32(28)\n\t" |
| |
| // set bit 3 of CR1 otherwise AIX 5.1 returns to the |
| // wrong address after the sc instruction |
| "crorc 6,6,6\n\t" |
| |
| // set up LR to point just after the sc insn |
| ".long 0x48000005\n\t" // "bl here+4" -- lr := & next insn |
| "mflr 29\n\t" |
| "addi 29,29,16\n\t" |
| "mtlr 29\n\t" |
| |
| // do it! |
| "sc\n\t" |
| |
| // result is now in r3; save it in args[0] |
| "stw 3,0(28)\n\t" |
| // error code in r4; save it in args[1] |
| "stw 4,4(28)\n\t" |
| |
| // restore |
| "mr 2,27\n\t" |
| "mtlr 30\n\t" |
| |
| : /*out*/ |
| : /*in*/ "b" (&args[0]) |
| : /*trash*/ |
| /*temps*/ "r31","r30","r29","r28","r27", |
| /*args*/ "r3","r4","r5","r6","r7","r8","r9","r10", |
| /*paranoia*/ "memory","cc","r0","r1","r11","r12","r13", |
| "xer","ctr","cr0","cr1","cr2","cr3", |
| "cr4","cr5","cr6","cr7" |
| ); |
| |
| *res_r3 = args[0]; |
| *res_r4 = args[1]; |
| } |
| |
| #elif defined(VGP_ppc64_aix5) |
| static void do_syscall_WRK ( UWord* res_r3, UWord* res_r4, |
| UWord sysno, |
| UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6, |
| UWord a7, UWord a8 ) |
| { |
| /* Same scheme as ppc32-aix5. */ |
| UWord args[9]; |
| args[0] = sysno; |
| args[1] = a1; args[2] = a2; |
| args[3] = a3; args[4] = a4; |
| args[5] = a5; args[6] = a6; |
| args[7] = a7; args[8] = a8; |
| |
| __asm__ __volatile__( |
| |
| // establish base ptr |
| "mr 28,%0\n\t" |
| |
| // save r2, lr |
| "mr 27,2\n\t" // save r2 in r27 |
| "mflr 30\n\t" // save lr in r30 |
| |
| // set syscall number and args |
| "ld 2, 0(28)\n\t" |
| "ld 3, 8(28)\n\t" |
| "ld 4, 16(28)\n\t" |
| "ld 5, 24(28)\n\t" |
| "ld 6, 32(28)\n\t" |
| "ld 7, 40(28)\n\t" |
| "ld 8, 48(28)\n\t" |
| "ld 9, 56(28)\n\t" |
| "ld 10, 64(28)\n\t" |
| |
| // set bit 3 of CR1 otherwise AIX 5.1 returns to the |
| // wrong address after the sc instruction |
| "crorc 6,6,6\n\t" |
| |
| // set up LR to point just after the sc insn |
| ".long 0x48000005\n\t" // "bl here+4" -- lr := & next insn |
| "mflr 29\n\t" |
| "addi 29,29,16\n\t" |
| "mtlr 29\n\t" |
| |
| // do it! |
| "sc\n\t" |
| |
| // result is now in r3; save it in args[0] |
| "std 3,0(28)\n\t" |
| // error code in r4; save it in args[1] |
| "std 4,8(28)\n\t" |
| |
| // restore |
| "mr 2,27\n\t" |
| "mtlr 30\n\t" |
| |
| : /*out*/ |
| : /*in*/ "b" (&args[0]) |
| : /*trash*/ |
| /*temps*/ "r31","r30","r29","r28","r27", |
| /*args*/ "r3","r4","r5","r6","r7","r8","r9","r10", |
| /*paranoia*/ "memory","cc","r0","r1","r11","r12","r13", |
| "xer","ctr","cr0","cr1","cr2","cr3", |
| "cr4","cr5","cr6","cr7" |
| ); |
| |
| *res_r3 = args[0]; |
| *res_r4 = args[1]; |
| } |
| |
| #else |
| # error Unknown platform |
| #endif |
| |
| |
| SysRes VG_(do_syscall) ( UWord sysno, UWord a1, UWord a2, UWord a3, |
| UWord a4, UWord a5, UWord a6, |
| UWord a7, UWord a8 ) |
| { |
| #if defined(VGP_x86_linux) |
| UWord val = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); |
| return VG_(mk_SysRes_x86_linux)( val ); |
| |
| #elif defined(VGP_amd64_linux) |
| UWord val = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); |
| return VG_(mk_SysRes_amd64_linux)( val ); |
| |
| #elif defined(VGP_ppc32_linux) |
| ULong ret = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); |
| UInt val = (UInt)(ret>>32); |
| UInt cr0so = (UInt)(ret); |
| return VG_(mk_SysRes_ppc32_linux)( val, cr0so ); |
| |
| #elif defined(VGP_ppc64_linux) |
| ULong argblock[7]; |
| argblock[0] = sysno; |
| argblock[1] = a1; |
| argblock[2] = a2; |
| argblock[3] = a3; |
| argblock[4] = a4; |
| argblock[5] = a5; |
| argblock[6] = a6; |
| do_syscall_WRK( &argblock[0] ); |
| return VG_(mk_SysRes_ppc64_linux)( argblock[0], argblock[1] ); |
| |
| #elif defined(VGP_ppc32_aix5) |
| UWord res; |
| UWord err; |
| do_syscall_WRK( &res, &err, |
| sysno, a1, a2, a3, a4, a5, a6, a7, a8); |
| /* Try to set the error number to zero if the syscall hasn't |
| really failed. */ |
| if (sysno == __NR_AIX5_kread |
| || sysno == __NR_AIX5_kwrite) { |
| if (res != (UWord)-1L) |
| err = 0; |
| } |
| else if (sysno == __NR_AIX5_sigprocmask |
| || sysno == __NR_AIX5__sigpending) { |
| if (res == 0) |
| err = 0; |
| } |
| |
| return VG_(mk_SysRes_ppc32_aix5)( res, err ); |
| |
| #elif defined(VGP_ppc64_aix5) |
| UWord res; |
| UWord err; |
| do_syscall_WRK( &res, &err, |
| sysno, a1, a2, a3, a4, a5, a6, a7, a8); |
| /* Try to set the error number to zero if the syscall hasn't |
| really failed. */ |
| if (sysno == __NR_AIX5_kread |
| || sysno == __NR_AIX5_kwrite) { |
| if (res != (UWord)-1L) |
| err = 0; |
| } |
| else if (sysno == __NR_AIX5_sigprocmask |
| || sysno == __NR_AIX5__sigpending) { |
| if (res == 0) |
| err = 0; |
| } |
| |
| return VG_(mk_SysRes_ppc64_aix5)( res, err ); |
| |
| #else |
| # error Unknown platform |
| #endif |
| } |
| |
| /* --------------------------------------------------------------------- |
| Names of errors. |
| ------------------------------------------------------------------ */ |
| |
| /* Return a string which gives the name of an error value. Note, |
| unlike the standard C syserror fn, the returned string is not |
| malloc-allocated or writable -- treat it as a constant. |
| TODO: implement this properly. */ |
| |
| const HChar* VG_(strerror) ( UWord errnum ) |
| { |
| switch (errnum) { |
| case VKI_EPERM: return "Operation not permitted"; |
| case VKI_ENOENT: return "No such file or directory"; |
| case VKI_ESRCH: return "No such process"; |
| case VKI_EINTR: return "Interrupted system call"; |
| case VKI_EBADF: return "Bad file number"; |
| case VKI_EAGAIN: return "Try again"; |
| case VKI_ENOMEM: return "Out of memory"; |
| case VKI_EACCES: return "Permission denied"; |
| case VKI_EFAULT: return "Bad address"; |
| case VKI_EEXIST: return "File exists"; |
| case VKI_EINVAL: return "Invalid argument"; |
| case VKI_EMFILE: return "Too many open files"; |
| case VKI_ENOSYS: return "Function not implemented"; |
| case VKI_EOVERFLOW: return "Value too large for defined data type"; |
| case VKI_ERESTARTSYS: return "ERESTARTSYS"; |
| default: return "VG_(strerror): unknown error"; |
| } |
| } |
| |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end ---*/ |
| /*--------------------------------------------------------------------*/ |