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Use a sv_copyout_auxargs hook in the Linux ELF ABIs.

Browse Source 
Reviewed by:	emaste
Tested on:	amd64 (linux64 only), i386
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D22356
This commit is contained in:
jhb 2019-11-15 23:01:43 +00:00
parent 1900fff82a
commit ad77a7b3cc
4 changed files with 77 additions and 93 deletions
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53
sys/amd64/linux/linux_sysvec.c
View File

@ -222,24 +222,17 @@ linux_set_syscall_retval(struct thread *td, int error)
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
static void
linux_copyout_auxargs(struct image_params *imgp, u_long *base)
{
Elf_Auxargs *args;
Elf_Auxinfo *argarray, *pos;
Elf_Addr *auxbase, *base;
struct ps_strings *arginfo;
u_long auxlen;
struct proc *p;
int error, issetugid;
int issetugid;
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
KASSERT(curthread->td_proc == imgp->proc,
("unsafe linux_fixup_elf(), should be curproc"));
base = (Elf64_Addr *)*stack_base;
args = (Elf64_Auxargs *)imgp->auxargs;
auxbase = base + imgp->args->argc + 1 + imgp->args->envc + 1;
argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
@ -267,15 +260,23 @@ linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
if (args->execfd != -1)
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
error = copyout(argarray, auxbase, sizeof(*argarray) * LINUX_AT_COUNT);
auxlen = sizeof(*argarray) * (pos - argarray);
*base -= auxlen;
copyout(argarray, (void *)*base, auxlen);
free(argarray, M_TEMP);
if (error != 0)
return (error);
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
{
Elf_Addr *base;
base = (Elf64_Addr *)*stack_base;
base--;
if (suword(base, (uint64_t)imgp->args->argc) == -1)
return (EFAULT);
@ -327,20 +328,6 @@ linux_copyout_strings(struct image_params *imgp)
copyout(canary, (void *)imgp->canary, sizeof(canary));
vectp = (char **)destp;
if (imgp->auxargs) {
/*
* Allocate room on the stack for the ELF auxargs
* array. It has LINUX_AT_COUNT entries.
*/
vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf64_Auxinfo),
sizeof(*vectp));
}
/*
* Allocate room for the argv[] and env vectors including the
* terminating NULL pointers.
*/
vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
/*
* Starting with 2.24, glibc depends on a 16-byte stack alignment.
@ -348,6 +335,15 @@ linux_copyout_strings(struct image_params *imgp)
*/
vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8);
if (imgp->auxargs)
imgp->sysent->sv_copyout_auxargs(imgp, (u_long *)&vectp);
/*
* Allocate room for the argv[] and env vectors including the
* terminating NULL pointers.
*/
vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
/* vectp also becomes our initial stack base. */
stack_base = (register_t *)vectp;
@ -715,6 +711,7 @@ struct sysentvec elf_linux_sysvec = {
.sv_usrstack = USRSTACK,
.sv_psstrings = PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_auxargs = linux_copyout_auxargs,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = NULL,

40
sys/amd64/linux32/linux32_sysvec.c
View File

@ -185,22 +185,15 @@ linux_translate_traps(int signal, int trap_code)
}
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
static void
linux_copyout_auxargs(struct image_params *imgp, u_long *base)
{
Elf32_Auxargs *args;
Elf32_Auxinfo *argarray, *pos;
Elf32_Addr *auxbase, *base;
struct linux32_ps_strings *arginfo;
int error, issetugid;
u_long auxlen;
int issetugid;
arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
KASSERT(curthread->td_proc == imgp->proc,
("unsafe linux_fixup_elf(), should be curproc"));
base = (Elf32_Addr *)*stack_base;
args = (Elf32_Auxargs *)imgp->auxargs;
auxbase = base + (imgp->args->argc + 1 + imgp->args->envc + 1);
argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
@ -244,12 +237,18 @@ linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
imgp->auxargs = NULL;
KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
error = copyout(&argarray[0], auxbase,
sizeof(*argarray) * LINUX_AT_COUNT);
auxlen = sizeof(*argarray) * (pos - argarray);
*base -= auxlen;
copyout(argarray, (void *)*base, auxlen);
free(argarray, M_TEMP);
if (error != 0)
return (error);
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
{
Elf32_Addr *base;
base = (Elf32_Addr *)*stack_base;
base--;
if (suword32(base, (uint32_t)imgp->args->argc) == -1)
return (EFAULT);
@ -755,14 +754,8 @@ linux_copyout_strings(struct image_params *imgp)
copyout(canary, (void *)imgp->canary, sizeof(canary));
vectp = (uint32_t *)destp;
if (imgp->auxargs) {
/*
* Allocate room on the stack for the ELF auxargs
* array. It has LINUX_AT_COUNT entries.
*/
vectp -= howmany(LINUX_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
@ -875,6 +868,7 @@ struct sysentvec elf_linux_sysvec = {
.sv_usrstack = LINUX32_USRSTACK,
.sv_psstrings = LINUX32_PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_auxargs = linux_copyout_auxargs,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = linux32_fixlimit,

42
sys/arm64/linux/linux_sysvec.c
View File

@ -87,6 +87,7 @@ LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
/* DTrace probes */
LIN_SDT_PROBE_DEFINE2(sysvec, linux_translate_traps, todo, "int", "int");
LIN_SDT_PROBE_DEFINE0(sysvec, linux_exec_setregs, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_copyout_auxargs, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_elf_fixup, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sigreturn, todo);
LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sendsig, todo);
@ -140,26 +141,19 @@ linux_set_syscall_retval(struct thread *td, int error)
cpu_set_syscall_retval(td, error);
}
static int
linux_elf_fixup(register_t **stack_base, struct image_params *imgp)
static void
linux_copyout_auxargs(struct image_params *imgp, u_long *base)
{
Elf_Auxargs *args;
Elf_Auxinfo *argarray, *pos;
Elf_Addr *auxbase, *base;
struct ps_strings *arginfo;
u_long auxlen;
struct proc *p;
int error, issetugid;
int issetugid;
LIN_SDT_PROBE0(sysvec, linux_elf_fixup, todo);
LIN_SDT_PROBE0(sysvec, linux_copyout_auxargs, todo);
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
KASSERT(curthread->td_proc == imgp->proc,
("unsafe linux_elf_fixup(), should be curproc"));
base = (Elf64_Addr *)*stack_base;
args = (Elf64_Auxargs *)imgp->auxargs;
/* Auxargs after argc, and NULL-terminated argv and envv lists. */
auxbase = base + 1 + imgp->args->argc + 1 + imgp->args->envc + 1;
argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
@ -195,10 +189,17 @@ linux_elf_fixup(register_t **stack_base, struct image_params *imgp)
imgp->auxargs = NULL;
KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
error = copyout(argarray, auxbase, sizeof(*argarray) * LINUX_AT_COUNT);
auxlen = sizeof(*argarray) * (pos - argarray);
*base -= auxlen;
copyout(argarray, (void *)*base, auxlen);
free(argarray, M_TEMP);
if (error != 0)
return (error);
}
static int
linux_elf_fixup(register_t **stack_base, struct image_params *imgp)
{
LIN_SDT_PROBE0(sysvec, linux_elf_fixup, todo);
return (0);
}
@ -247,14 +248,8 @@ linux_copyout_strings(struct image_params *imgp)
copyout(canary, (void *)imgp->canary, sizeof(canary));
vectp = (char **)destp;
if (imgp->auxargs) {
/*
* Allocate room on the stack for the ELF auxargs
* array. It has up to LINUX_AT_COUNT entries.
*/
vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf64_Auxinfo),
sizeof(*vectp));
}
if (imgp->auxargs)
imgp->sysent->sv_copyout_auxargs(imgp, (u_long *)&vectp);
/*
* Allocate room for argc and the argv[] and env vectors including the
@ -372,6 +367,7 @@ struct sysentvec elf_linux_sysvec = {
.sv_usrstack = USRSTACK,
.sv_psstrings = PS_STRINGS, /* XXX */
.sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
.sv_copyout_auxargs = linux_copyout_auxargs,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = NULL,

35
sys/i386/linux/linux_sysvec.c
View File

@ -188,25 +188,22 @@ linux_fixup(register_t **stack_base, struct image_params *imgp)
return (0);
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
static void
linux_copyout_auxargs(struct image_params *imgp, u_long *base)
{
struct proc *p;
Elf32_Auxargs *args;
Elf32_Auxinfo *argarray, *pos;
Elf32_Addr *auxbase, *uplatform;
Elf32_Addr *uplatform;
struct ps_strings *arginfo;
int error, issetugid;
KASSERT(curthread->td_proc == imgp->proc,
("unsafe linux_fixup_elf(), should be curproc"));
u_long auxlen;
int issetugid;
p = imgp->proc;
issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
args = (Elf32_Auxargs *)imgp->auxargs;
auxbase = *stack_base + imgp->args->argc + 1 + imgp->args->envc + 1;
argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
@ -249,10 +246,15 @@ linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
imgp->auxargs = NULL;
KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
error = copyout(argarray, auxbase, sizeof(*argarray) * LINUX_AT_COUNT);
auxlen = sizeof(*argarray) * (pos - argarray);
*base -= auxlen;
copyout(argarray, (void *)*base, auxlen);
free(argarray, M_TEMP);
if (error != 0)
return (error);
}
static int
linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
{
(*stack_base)--;
if (suword(*stack_base, (register_t)imgp->args->argc) == -1)
@ -305,14 +307,8 @@ linux_copyout_strings(struct image_params *imgp)
copyout(canary, (void *)imgp->canary, sizeof(canary));
vectp = (char **)destp;
if (imgp->auxargs) {
/*
* Allocate room on the stack for the ELF auxargs
* array. It has LINUX_AT_COUNT entries.
*/
vectp -= howmany(LINUX_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
@ -851,6 +847,7 @@ struct sysentvec elf_linux_sysvec = {
.sv_usrstack = LINUX_USRSTACK,
.sv_psstrings = LINUX_PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_auxargs = linux_copyout_auxargs,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = linux_exec_setregs,
.sv_fixlimit = NULL,