Date: Fri, 15 Nov 2019 22:01:08 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: John Baldwin <jhb@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r354741 - in head/sys: amd64/amd64 arm/arm arm64/arm64 compat/freebsd32 compat/ia32 i386/i386 kern mips/mips powerpc/powerpc riscv/riscv sparc64/sparc64 sys Message-ID: <20191115200108.GH2707@kib.kiev.ua> In-Reply-To: <201911151842.xAFIgDrJ093716@repo.freebsd.org> References: <201911151842.xAFIgDrJ093716@repo.freebsd.org>
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On Fri, Nov 15, 2019 at 06:42:13PM +0000, John Baldwin wrote: > Author: jhb > Date: Fri Nov 15 18:42:13 2019 > New Revision: 354741 > URL: https://svnweb.freebsd.org/changeset/base/354741 > > Log: > Add a sv_copyout_auxargs() hook in sysentvec. > > Change the FreeBSD ELF ABIs to use this new hook to copyout ELF auxv > instead of doing it in the sv_fixup hook. In particular, this new > hook allows the stack space to be allocated at the same time the auxv > values are copied out to userland. This allows us to avoid wasting > space for unused auxv entries as well as not having to recalculate > where the auxv vector is by walking back up over the argv and > environment vectors. > > Reviewed by: brooks, emaste > Tested on: amd64 (amd64 and i386 binaries), i386, mips, mips64 > Sponsored by: DARPA > Differential Revision: https://reviews.freebsd.org/D22355 > > Modified: > head/sys/amd64/amd64/elf_machdep.c > head/sys/arm/arm/elf_machdep.c > head/sys/arm64/arm64/elf32_machdep.c > head/sys/arm64/arm64/elf_machdep.c > head/sys/compat/freebsd32/freebsd32_misc.c > head/sys/compat/ia32/ia32_sysvec.c > head/sys/i386/i386/elf_machdep.c > head/sys/kern/imgact_elf.c > head/sys/kern/kern_exec.c > head/sys/mips/mips/elf_machdep.c > head/sys/mips/mips/freebsd32_machdep.c > head/sys/powerpc/powerpc/elf32_machdep.c > head/sys/powerpc/powerpc/elf64_machdep.c > head/sys/riscv/riscv/elf_machdep.c > head/sys/sparc64/sparc64/elf_machdep.c > head/sys/sys/imgact_elf.h > head/sys/sys/sysent.h > > Modified: head/sys/amd64/amd64/elf_machdep.c > ============================================================================== > --- head/sys/amd64/amd64/elf_machdep.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/amd64/amd64/elf_machdep.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -68,6 +68,7 @@ struct sysentvec elf64_freebsd_sysvec = { > .sv_usrstack = USRSTACK, > .sv_psstrings = PS_STRINGS, > .sv_stackprot = VM_PROT_ALL, > + .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), > .sv_copyout_strings = exec_copyout_strings, > .sv_setregs = exec_setregs, > .sv_fixlimit = NULL, > > Modified: head/sys/arm/arm/elf_machdep.c > ============================================================================== > --- head/sys/arm/arm/elf_machdep.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/arm/arm/elf_machdep.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -75,6 +75,7 @@ struct sysentvec elf32_freebsd_sysvec = { > .sv_usrstack = USRSTACK, > .sv_psstrings = PS_STRINGS, > .sv_stackprot = VM_PROT_ALL, > + .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), > .sv_copyout_strings = exec_copyout_strings, > .sv_setregs = exec_setregs, > .sv_fixlimit = NULL, > > Modified: head/sys/arm64/arm64/elf32_machdep.c > ============================================================================== > --- head/sys/arm64/arm64/elf32_machdep.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/arm64/arm64/elf32_machdep.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -92,6 +92,7 @@ static struct sysentvec elf32_freebsd_sysvec = { > .sv_usrstack = FREEBSD32_USRSTACK, > .sv_psstrings = FREEBSD32_PS_STRINGS, > .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, > + .sv_copyout_auxargs = elf32_freebsd_copyout_auxargs, > .sv_copyout_strings = freebsd32_copyout_strings, > .sv_setregs = freebsd32_setregs, > .sv_fixlimit = NULL, // XXX > > Modified: head/sys/arm64/arm64/elf_machdep.c > ============================================================================== > --- head/sys/arm64/arm64/elf_machdep.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/arm64/arm64/elf_machdep.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -76,6 +76,7 @@ static struct sysentvec elf64_freebsd_sysvec = { > .sv_usrstack = USRSTACK, > .sv_psstrings = PS_STRINGS, > .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, > + .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), > .sv_copyout_strings = exec_copyout_strings, > .sv_setregs = exec_setregs, > .sv_fixlimit = NULL, > > Modified: head/sys/compat/freebsd32/freebsd32_misc.c > ============================================================================== > --- head/sys/compat/freebsd32/freebsd32_misc.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/compat/freebsd32/freebsd32_misc.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -3195,14 +3195,8 @@ freebsd32_copyout_strings(struct image_params *imgp) > if (imgp->sysent->sv_stackgap != NULL) > imgp->sysent->sv_stackgap(imgp, (u_long *)&vectp); > > - if (imgp->auxargs) { > - /* > - * Allocate room on the stack for the ELF auxargs > - * array. It has up to AT_COUNT entries. > - */ > - vectp -= howmany(AT_COUNT * sizeof(Elf32_Auxinfo), > - sizeof(*vectp)); > - } > + if (imgp->auxargs) > + imgp->sysent->sv_copyout_auxargs(imgp, (u_long *)&vectp); > > /* > * Allocate room for the argv[] and env vectors including the > > Modified: head/sys/compat/ia32/ia32_sysvec.c > ============================================================================== > --- head/sys/compat/ia32/ia32_sysvec.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/compat/ia32/ia32_sysvec.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -114,6 +114,7 @@ struct sysentvec ia32_freebsd_sysvec = { > .sv_usrstack = FREEBSD32_USRSTACK, > .sv_psstrings = FREEBSD32_PS_STRINGS, > .sv_stackprot = VM_PROT_ALL, > + .sv_copyout_auxargs = elf32_freebsd_copyout_auxargs, > .sv_copyout_strings = freebsd32_copyout_strings, > .sv_setregs = ia32_setregs, > .sv_fixlimit = ia32_fixlimit, > > Modified: head/sys/i386/i386/elf_machdep.c > ============================================================================== > --- head/sys/i386/i386/elf_machdep.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/i386/i386/elf_machdep.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -70,6 +70,7 @@ struct sysentvec elf32_freebsd_sysvec = { > .sv_usrstack = USRSTACK, > .sv_psstrings = PS_STRINGS, > .sv_stackprot = VM_PROT_ALL, > + .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), > .sv_copyout_strings = exec_copyout_strings, > .sv_setregs = exec_setregs, > .sv_fixlimit = NULL, > > Modified: head/sys/kern/imgact_elf.c > ============================================================================== > --- head/sys/kern/imgact_elf.c Fri Nov 15 18:34:36 2019 (r354740) > +++ head/sys/kern/imgact_elf.c Fri Nov 15 18:42:13 2019 (r354741) > @@ -1289,7 +1289,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i > addr = et_dyn_addr; > > /* > - * Construct auxargs table (used by the fixup routine) > + * Construct auxargs table (used by the copyout_auxargs routine) > */ > elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_NOWAIT); > if (elf_auxargs == NULL) { > @@ -1323,16 +1323,13 @@ ret: > > #define suword __CONCAT(suword, __ELF_WORD_SIZE) > > -int > -__elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp) > +void > +__elfN(freebsd_copyout_auxargs)(struct image_params *imgp, u_long *base) > { > Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; > Elf_Auxinfo *argarray, *pos; > - Elf_Addr *base, *auxbase; > - int error; > + u_long auxlen; > > - base = (Elf_Addr *)*stack_base; > - auxbase = base + imgp->args->argc + 1 + imgp->args->envc + 1; > argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP, > M_WAITOK | M_ZERO); > > @@ -1376,11 +1373,18 @@ __elfN(freebsd_fixup)(register_t **stack_base, struct > imgp->auxargs = NULL; > KASSERT(pos - argarray <= AT_COUNT, ("Too many auxargs")); > > - error = copyout(argarray, auxbase, sizeof(*argarray) * AT_COUNT); > + auxlen = sizeof(*argarray) * (pos - argarray); > + *base -= auxlen; > + copyout(argarray, (void *)*base, auxlen); > free(argarray, M_TEMP); > - if (error != 0) > - return (error); > +} So you are ignoring copyout errors ?
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