From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id 7374F385800A; Thu, 9 Feb 2023 11:40:46 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7374F385800A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1675942846; bh=CVpSOyMFW340DJqKz9HcsoyOILlAs0lJuvJFMfmN6RQ=; h=From:To:Subject:Date:From; b=i84J8rLe4JLe9yHj4KyeDgNh6c36xoI+S1el6t3D/A44CcAJC734b9174ZNf2HNaM Hq00dpf/FmeQ0lPwgdXip3lo+xvhH8vGoXfv0mfITOttmITVM4M4So0LWq3NFgLwuv O4o49RZ/HJJlgo0uCeW77tMAcj0GsyK1+qiRobBQ= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc] powerpc64: Add the clone3 wrapper X-Act-Checkin: glibc X-Git-Author: Adhemerval Zanella Netto X-Git-Refname: refs/heads/master X-Git-Oldrev: fb95c316382679c0826cc8399760977cd95f15c9 X-Git-Newrev: 16e424a325bc8ece973e4ef4758f12f15355ec57 Message-Id: <20230209114046.7374F385800A@sourceware.org> Date: Thu, 9 Feb 2023 11:40:46 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=16e424a325bc8ece973e4ef4758f12f15355ec57 commit 16e424a325bc8ece973e4ef4758f12f15355ec57 Author: Adhemerval Zanella Netto Date: Fri Feb 3 14:12:33 2023 -0300 powerpc64: Add the clone3 wrapper It follows the internal signature: extern int clone3 (struct clone_args *__cl_args, size_t __size, int (*__func) (void *__arg), void *__arg); The powerpc64 ABI requires an initial stackframe so the child can store/restore the TOC. It is create prior calling clone3 by adjusting the stack size (since kernel will compute the stack as stack plus size). Checked on powerpc64-linux-gnu (power8, kernel 6.0) and powerpc64le-linux-gnu (power9, kernel 4.18). Reviewed-by: Paul E. Murphy Diff: --- sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S | 157 +++++++++++++++++++++ sysdeps/unix/sysv/linux/powerpc/sysdep.h | 1 + 2 files changed, 158 insertions(+) diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S new file mode 100644 index 0000000000..3c50fe392f --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S @@ -0,0 +1,157 @@ +/* The clone3 syscall wrapper. Linux/powerpc64 version. + Copyright (C) 2023 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#define _ERRNO_H 1 +#include + +/* The userland implementation is: + int clone3 (struct clone_args *cl_args, size_t size, + int (*func)(void *arg), void *arg); + + the kernel entry is: + int clone3 (struct clone_args *cl_args, size_t size); + + The parameters are passed in registers from userland: + r3: cl_args + r4: size + r5: func + r6: arg */ + +#ifdef USE_PPC_SCV +/* This is equivalent to DO_CALL_SCV, but we cannot use the macro here + because it uses CFI directives and we just called cfi_endproc. */ +# define DO_CLONE3_SVC_CALL(jumpfalse) \ + CHECK_SCV_SUPPORT r28 jumpfalse; \ + mflr r9; \ + std r9, FRAME_LR_SAVE(r1); \ + .machine "push"; \ + .machine "power9"; \ + scv 0; \ + .machine "pop"; \ + ld r9, FRAME_LR_SAVE(r1); \ + mtlr r9; \ + /* With scv an, an error is a value -4095 <= x < 0. */ \ + cmpdi cr1, r3, 0; \ + b 1f; +#else +# define DO_CLONE3_SVC_CALL(fail_branch) +#endif + + .text +ENTRY(__clone3) + CALL_MCOUNT 4 + + /* Sanity checks args. */ + cmpdi cr0, r3, 0 + cmpdi cr1, r5, 0 + cror cr0*4+eq, cr1*4+eq, cr0*4+eq + beq cr0,L(badargs) + + /* Save some regs in the "red zone". */ +#ifdef USE_PPC_SCV + std r28, -24(r1) + cfi_offset (r28, -24) +#endif + std r29, -16(r1) + std r30, -8(r1) + cfi_offset (r29, -16) + cfi_offset (r30, -8) + + /* Save func and arg across syscall. */ + mr r30, r5 /* Function in r30. */ + mr r29, r6 /* Argument in r29. */ + + /* End FDE now, because in the child the unwind info will be + wrong. */ + cfi_endproc + + /* Setup a minimum stack frame for child. It needs to first calculate + the effective stack address, write the start empty backchain pointer, + and update the frame size in the input cl_args. */ + ld r7, 40(r3) /* Load stack value. */ + ld r8, 48(r3) /* Load stack_size value. */ + li r10, 0 + add r7, r7, r8 /* Calculate effective stack address. */ + std r10, -FRAME_MIN_SIZE_PARM(r7) + addi r8, r8, -FRAME_MIN_SIZE_PARM + std r8, 48(r3) + + /* Do the system call, the kernel expects: + r0: system call numer + r3: cl_args + r4: size */ + li r0, SYS_ify(clone3) + DO_CLONE3_SVC_CALL (0f) +0: DO_CALL_SC + + /* With sc, error is indicated by cr0.SO. */ + cmpdi cr1, r3, 0 + crandc cr1*4+eq, cr1*4+eq, cr0*4+so + +1: bne- cr1,L(parent) + + /* Child, load the function and arguments. */ + std r2, FRAME_TOC_SAVE(r1) + PPC64_LOAD_FUNCPTR r30 + mr r3, r29 + bctrl + ld r2, FRAME_TOC_SAVE(r1) + + li r0, SYS_ify(exit) + DO_CLONE3_SVC_CALL (2f) +2: DO_CALL_SC + /* We won't ever get here but provide a nop so that the linker + will insert a toc adjusting stub if necessary. */ + nop + +L(badargs): + cfi_startproc + li r3, EINVAL + TAIL_CALL_SYSCALL_ERROR + +L(parent): + /* Check if scv is available. */ + cmpdi cr1, r28, 0 + + /* Parent. Restore registers & return. */ +#ifdef USE_PPC_SCV + cfi_offset (r28, -24) + ld r28, -24(r1) + cfi_restore (r28) +#endif + cfi_offset (r29,-16) + cfi_offset (r30,-8) + ld r29, -16(r1) + ld r30, -8(r1) + cfi_restore (r29) + cfi_restore (r30) + +#ifdef USE_PPC_SCV + beq cr1, 0f + RET_SCV + b 1f +#endif +0: RET_SC +1: TAIL_CALL_SYSCALL_ERROR + +PSEUDO_END (__clone3) + +libc_hidden_def (__clone3) +weak_alias (__clone3, clone3) diff --git a/sysdeps/unix/sysv/linux/powerpc/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/sysdep.h index 9859cb8171..96a0edc38f 100644 --- a/sysdeps/unix/sysv/linux/powerpc/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/sysdep.h @@ -214,6 +214,7 @@ #if defined(__PPC64__) || defined(__powerpc64__) #define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres" #define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime" +#define HAVE_CLONE3_WRAPPER 1 #else #define HAVE_CLOCK_GETRES_VSYSCALL "__kernel_clock_getres" #define HAVE_CLOCK_GETTIME_VSYSCALL "__kernel_clock_gettime"