PATCH: ptrace support for fork/vfork/clone events [2/3]

Daniel Jacobowitz (dan@debian.org)
Sun, 27 Oct 2002 13:52:13 -0500

Messages sorted by: [ date ][ thread ][ subject ][ author ]
Next message: Daniel Jacobowitz: "PATCH: ptrace support for fork/vfork/clone events [3/3]"
Previous message: Daniel Jacobowitz: "PATCH: ptrace support for fork/vfork/clone events [1/3]"

On Sun, Oct 27, 2002 at 01:50:38PM -0500, Daniel Jacobowitz wrote:
> 2. Add a new clone flag, CLONE_UNTRACED, and force it in all kernel_thread
> implementations. Needed by the next patch. This one touches every
> architecture and some of them in assembly; I've tried to get them all
> correct.

Here's the second one.

[Why is this needed? It's needed so that the debugger doesn't get
triggered on, say, a kernel-started modprobe process or some other
kernel thread. That'd confuse the debugger, beyond the other possible
security/stability problems.]

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.809 -> 1.810
# arch/i386/kernel/process.c 1.32 -> 1.33
# arch/alpha/kernel/entry.S 1.15.1.2 -> 1.17
# arch/x86_64/kernel/process.c 1.7.1.3 -> 1.9
# include/linux/sched.h 1.94.1.14 -> 1.96
# arch/sparc/kernel/process.c 1.18 -> 1.19
# arch/s390x/kernel/process.c 1.10.1.4 -> 1.12
# arch/parisc/kernel/entry.S 1.3 -> 1.5
# arch/mips64/kernel/process.c 1.4 -> 1.5
# arch/ppc64/kernel/misc.S 1.28 -> 1.29
# arch/mips/kernel/process.c 1.7 -> 1.8
# arch/cris/kernel/entry.S 1.12 -> 1.13
# arch/sparc64/kernel/process.c 1.35 -> 1.36
# arch/ia64/kernel/process.c 1.15.1.1 -> 1.17
# arch/m68k/kernel/process.c 1.10 -> 1.11
# arch/cris/kernel/entryoffsets.c 1.3 -> 1.4
# arch/ppc64/kernel/asm-offsets.c 1.11 -> 1.12
# arch/sh/kernel/process.c 1.12 -> 1.13
# arch/s390/kernel/process.c 1.12.1.4 -> 1.14
# arch/arm/kernel/process.c 1.20 -> 1.21
# arch/ppc/kernel/misc.S 1.29 -> 1.30
# arch/alpha/kernel/asm-offsets.c 1.6 -> 1.7
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/26 drow@nevyn.them.org 1.810
# Merge to kernel.org
# --------------------------------------------
#
diff -Nru a/arch/alpha/kernel/asm-offsets.c b/arch/alpha/kernel/asm-offsets.c
--- a/arch/alpha/kernel/asm-offsets.c Sat Oct 26 20:09:43 2002
+++ b/arch/alpha/kernel/asm-offsets.c Sat Oct 26 20:09:43 2002
@@ -22,6 +22,7 @@
BLANK();
DEFINE(PT_PTRACED, PT_PTRACED);
DEFINE(CLONE_VM, CLONE_VM);
+ DEFINE(CLONE_UNTRACED, CLONE_UNTRACED);
DEFINE(SIGCHLD, SIGCHLD);
BLANK();
DEFINE(HAE_CACHE, offsetof(struct alpha_machine_vector, hae_cache));
diff -Nru a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
--- a/arch/alpha/kernel/entry.S Sat Oct 26 20:09:43 2002
+++ b/arch/alpha/kernel/entry.S Sat Oct 26 20:09:43 2002
@@ -212,7 +212,7 @@
stq $2, 152($30) /* HAE */

/* Shuffle FLAGS to the front; add CLONE_VM. */
- ldi $1, CLONE_VM
+ ldi $1, CLONE_VM|CLONE_UNTRACED
or $18, $1, $16
bsr $26, sys_clone

diff -Nru a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
--- a/arch/arm/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/arm/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -403,7 +403,7 @@
b sys_exit \n\
1: "
: "=r" (__ret)
- : "Ir" (flags), "I" (CLONE_VM), "r" (fn), "r" (arg)
+ : "Ir" (flags), "r" (CLONE_VM | CLONE_UNTRACED), "r" (fn), "r" (arg)
: "r0", "r1", "lr");
return __ret;
}
diff -Nru a/arch/cris/kernel/entry.S b/arch/cris/kernel/entry.S
--- a/arch/cris/kernel/entry.S Sat Oct 26 20:09:43 2002
+++ b/arch/cris/kernel/entry.S Sat Oct 26 20:09:43 2002
@@ -748,6 +748,7 @@
/* r11 is argument 2 to clone, the flags */
move.d $r12, $r11
or.w LCLONE_VM, $r11
+ or.w LCLONE_UNTRACED, $r11

/* Save FN for later. */
move.d $r10, $r12
diff -Nru a/arch/cris/kernel/entryoffsets.c b/arch/cris/kernel/entryoffsets.c
--- a/arch/cris/kernel/entryoffsets.c Sat Oct 26 20:09:43 2002
+++ b/arch/cris/kernel/entryoffsets.c Sat Oct 26 20:09:43 2002
@@ -57,5 +57,6 @@

/* linux/sched.h values - doesn't have an #ifdef __ASSEMBLY__ for these. */
VAL (LCLONE_VM, CLONE_VM)
+VAL (LCLONE_UNTRACED, CLONE_UNTRACED)

__asm__ (".endif");
diff -Nru a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
--- a/arch/i386/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/i386/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -224,7 +224,7 @@
regs.eflags = 0x286;

/* Ok, create the new process.. */
- p = do_fork(flags | CLONE_VM, 0, &regs, 0, NULL);
+ p = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL);
return IS_ERR(p) ? PTR_ERR(p) : p->pid;
}

diff -Nru a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
--- a/arch/ia64/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/ia64/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -514,7 +514,7 @@
struct task_struct *parent = current;
int result, tid;

- tid = clone(flags | CLONE_VM, 0);
+ tid = clone(flags | CLONE_VM | CLONE_UNTRACED, 0);
if (parent != current) {
result = (*fn)(arg);
_exit(result);
diff -Nru a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
--- a/arch/m68k/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/m68k/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -152,7 +152,7 @@

{
register long retval __asm__ ("d0");
- register long clone_arg __asm__ ("d1") = flags | CLONE_VM;
+ register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;

retval = __NR_clone;
__asm__ __volatile__
diff -Nru a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
--- a/arch/mips/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/mips/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -176,7 +176,7 @@
:"=r" (retval)
:"i" (__NR_clone), "i" (__NR_exit),
"r" (arg), "r" (fn),
- "r" (flags | CLONE_VM)
+ "r" (flags | CLONE_VM | CLONE_UNTRACED)
/*
* The called subroutine might have destroyed any of the
* at, result, argument or temporary registers ...
diff -Nru a/arch/mips64/kernel/process.c b/arch/mips64/kernel/process.c
--- a/arch/mips64/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/mips64/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -167,7 +167,7 @@
"1:\tmove\t%0, $2"
:"=r" (retval)
:"i" (__NR_clone), "i" (__NR_exit), "r" (arg), "r" (fn),
- "r" (flags | CLONE_VM)
+ "r" (flags | CLONE_VM | CLONE_UNTRACED)

/* The called subroutine might have destroyed any of the
* at, result, argument or temporary registers ... */
diff -Nru a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
--- a/arch/parisc/kernel/entry.S Sat Oct 26 20:09:43 2002
+++ b/arch/parisc/kernel/entry.S Sat Oct 26 20:09:43 2002
@@ -482,6 +482,7 @@
*/

#define CLONE_VM 0x100 /* Must agree with <linux/sched.h> */
+#define CLONE_UNTRACED 0x00800000

.export __kernel_thread, code
.import do_fork
@@ -497,7 +498,8 @@
#endif
STREG %r26, PT_GR26(%r1) /* Store function & argument for child */
STREG %r25, PT_GR25(%r1)
- ldo CLONE_VM(%r0), %r26 /* Force CLONE_VM since only init_mm */
+ ldil L%CLONE_UNTRACED, %r26
+ ldo CLONE_VM(%r26), %r26 /* Force CLONE_VM since only init_mm */
or %r26, %r24, %r26 /* will have kernel mappings. */
copy %r0, %r25
bl do_fork_FIXME_NOW_RETURNS_TASK_STRUCT, %r2
diff -Nru a/arch/ppc/kernel/misc.S b/arch/ppc/kernel/misc.S
--- a/arch/ppc/kernel/misc.S Sat Oct 26 20:09:43 2002
+++ b/arch/ppc/kernel/misc.S Sat Oct 26 20:09:43 2002
@@ -1005,6 +1005,7 @@
mr r30,r3 /* function */
mr r31,r4 /* argument */
ori r3,r5,CLONE_VM /* flags */
+ oris r3,r3,CLONE_UNTRACED>>16
li r0,__NR_clone
sc
cmpi 0,r3,0 /* parent or child? */
diff -Nru a/arch/ppc64/kernel/asm-offsets.c b/arch/ppc64/kernel/asm-offsets.c
--- a/arch/ppc64/kernel/asm-offsets.c Sat Oct 26 20:09:43 2002
+++ b/arch/ppc64/kernel/asm-offsets.c Sat Oct 26 20:09:43 2002
@@ -157,6 +157,7 @@
DEFINE(_SRR1, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)+8);

DEFINE(CLONE_VM, CLONE_VM);
+ DEFINE(CLONE_UNTRACED, CLONE_UNTRACED);

return 0;
}
diff -Nru a/arch/ppc64/kernel/misc.S b/arch/ppc64/kernel/misc.S
--- a/arch/ppc64/kernel/misc.S Sat Oct 26 20:09:43 2002
+++ b/arch/ppc64/kernel/misc.S Sat Oct 26 20:09:43 2002
@@ -486,6 +486,7 @@
/* XXX fix this when we optimise syscall entry to not save volatiles */
mr r6,r3 /* function */
ori r3,r5,CLONE_VM /* flags */
+ oris r3,r3,(CLONE_UNTRACED>>16)
li r0,__NR_clone
sc
cmpi 0,r3,0 /* parent or child? */
diff -Nru a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
--- a/arch/s390/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/s390/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -146,7 +146,7 @@
regs.orig_gpr2 = -1;

/* Ok, create the new process.. */
- p = do_fork(flags | CLONE_VM, 0, &regs, 0, NULL);
+ p = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL);
return IS_ERR(p) ? PTR_ERR(p) : p->pid;
}

diff -Nru a/arch/s390x/kernel/process.c b/arch/s390x/kernel/process.c
--- a/arch/s390x/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/s390x/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -143,7 +143,7 @@
regs.orig_gpr2 = -1;

/* Ok, create the new process.. */
- p = do_fork(flags | CLONE_VM, 0, &regs, 0, NULL);
+ p = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL);
return IS_ERR(p) ? PTR_ERR(p) : p->pid;
}

diff -Nru a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
--- a/arch/sh/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/sh/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -120,7 +120,7 @@
{ /* Don't use this in BL=1(cli). Or else, CPU resets! */
register unsigned long __sc0 __asm__ ("r0");
register unsigned long __sc3 __asm__ ("r3") = __NR_clone;
- register unsigned long __sc4 __asm__ ("r4") = (long) flags | CLONE_VM;
+ register unsigned long __sc4 __asm__ ("r4") = (long) flags | CLONE_VM | CLONE_UNTRACED;
register unsigned long __sc5 __asm__ ("r5") = 0;
register unsigned long __sc8 __asm__ ("r8") = (long) arg;
register unsigned long __sc9 __asm__ ("r9") = (long) fn;
diff -Nru a/arch/sparc/kernel/process.c b/arch/sparc/kernel/process.c
--- a/arch/sparc/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/sparc/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -726,7 +726,7 @@
/* Notreached by child. */
"1: mov %%o0, %0\n\t" :
"=r" (retval) :
- "i" (__NR_clone), "r" (flags | CLONE_VM),
+ "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
"i" (__NR_exit), "r" (fn), "r" (arg) :
"g1", "g2", "g3", "o0", "o1", "memory", "cc");
return retval;
diff -Nru a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
--- a/arch/sparc64/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/sparc64/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -694,7 +694,7 @@
/* Notreached by child. */
"1:" :
"=r" (retval) :
- "i" (__NR_clone), "r" (flags | CLONE_VM),
+ "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
"i" (__NR_exit), "r" (fn), "r" (arg) :
"g1", "g2", "g3", "o0", "o1", "memory", "cc");
return retval;
diff -Nru a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
--- a/arch/x86_64/kernel/process.c Sat Oct 26 20:09:43 2002
+++ b/arch/x86_64/kernel/process.c Sat Oct 26 20:09:43 2002
@@ -59,7 +59,7 @@
asmlinkage extern void ret_from_fork(void);
int sys_arch_prctl(int code, unsigned long addr);

-unsigned long kernel_thread_flags = CLONE_VM;
+unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;

int hlt_counter;

diff -Nru a/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h Sat Oct 26 20:09:43 2002
+++ b/include/linux/sched.h Sat Oct 26 20:09:43 2002
@@ -51,6 +51,7 @@
#define CLONE_SETTID 0x00100000 /* write the TID back to userspace */
#define CLONE_CLEARTID 0x00200000 /* clear the userspace TID */
#define CLONE_DETACHED 0x00400000 /* parent wants no child-exit signal */
+#define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */

/*
* List of flags we want to share for kernel threads,

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Next message: Daniel Jacobowitz: "PATCH: ptrace support for fork/vfork/clone events [3/3]"
Previous message: Daniel Jacobowitz: "PATCH: ptrace support for fork/vfork/clone events [1/3]"