[PATCH] linux 2.6.0-test1: do_fork() return value for ARCH=um,m68k,s390,h8300

From: Philippe Biondi (biondi@cartel-securite.fr)
Date: Sun Jul 20 2003 - 17:03:32 EST

Hi all,

I tried to compile linux-2.6.0-test1 with ARCH=um.

First, I noticed that some functions expected do_fork() to return a
task_struct *. I don't know why. I find this really strange, did I miss
something ?

Here is the patch :

diff -Nrup linux-2.6.0-test1-ori/arch/h8300/kernel/process.c linux-2.6.0-test1/arch/h8300/kernel/process.c
--- linux-2.6.0-test1-ori/arch/h8300/kernel/process.c 2003-07-14 05:28:54.000000000 +0200
+++ linux-2.6.0-test1/arch/h8300/kernel/process.c 2003-07-20 17:58:56.000000000 +0200
@@ -172,25 +172,20 @@ asmlinkage int h8300_fork(struct pt_regs

 asmlinkage int h8300_vfork(struct pt_regs *regs)
 {
- struct task_struct *p;
- p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 }

 asmlinkage int h8300_clone(struct pt_regs *regs)
 {
         unsigned long clone_flags;
         unsigned long newsp;
- struct task_struct *p;

         /* syscall2 puts clone_flags in er1 and usp in er2 */
         clone_flags = regs->er1;
         newsp = regs->er2;
         if (!newsp)
                 newsp = rdusp();
- p = do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0, NULL, NULL);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
-
+ return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0, NULL, NULL);
 }

 int copy_thread(int nr, unsigned long clone_flags,
diff -Nrup linux-2.6.0-test1-ori/arch/m68k/kernel/process.c linux-2.6.0-test1/arch/m68k/kernel/process.c
--- linux-2.6.0-test1-ori/arch/m68k/kernel/process.c 2003-07-14 05:39:32.000000000 +0200
+++ linux-2.6.0-test1/arch/m68k/kernel/process.c 2003-07-20 17:55:34.000000000 +0200
@@ -202,24 +202,19 @@ void flush_thread(void)

 asmlinkage int m68k_fork(struct pt_regs *regs)
 {
- struct task_struct *p;
- p = do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
+ return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 }

 asmlinkage int m68k_vfork(struct pt_regs *regs)
 {
- struct task_struct *p;
- p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
                     NULL);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }

 asmlinkage int m68k_clone(struct pt_regs *regs)
 {
         unsigned long clone_flags;
         unsigned long newsp;
- struct task_struct *p;
         int *parent_tidptr, *child_tidptr;

         /* syscall2 puts clone_flags in d1 and usp in d2 */
@@ -229,9 +224,8 @@ asmlinkage int m68k_clone(struct pt_regs
         child_tidptr = (int *)regs->d4;
         if (!newsp)
                 newsp = rdusp();
- p = do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0,
+ return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0,
                     parent_tidptr, child_tidptr);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }

 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
diff -Nrup linux-2.6.0-test1-ori/arch/s390/kernel/compat_linux.c linux-2.6.0-test1/arch/s390/kernel/compat_linux.c
--- linux-2.6.0-test1-ori/arch/s390/kernel/compat_linux.c 2003-07-14 05:37:14.000000000 +0200
+++ linux-2.6.0-test1/arch/s390/kernel/compat_linux.c 2003-07-20 17:59:34.000000000 +0200
@@ -2809,7 +2809,6 @@ asmlinkage int sys32_clone(struct pt_reg
 {
         unsigned long clone_flags;
         unsigned long newsp;
- struct task_struct *p;
         int *parent_tidptr, *child_tidptr;

         clone_flags = regs.gprs[3] & 0xffffffffUL;
@@ -2818,7 +2817,6 @@ asmlinkage int sys32_clone(struct pt_reg
         child_tidptr = (int *) (regs.gprs[5] & 0x7fffffffUL);
         if (!newsp)
                 newsp = regs.gprs[15];
- p = do_fork(clone_flags & ~CLONE_IDLETASK, newsp, &regs, 0,
- parent_tidptr, child_tidptr);
- return IS_ERR(p) ? PTR_ERR(p) : p->pid;
+ return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, &regs, 0,
+ parent_tidptr, child_tidptr);
 }
diff -Nrup linux-2.6.0-test1-ori/arch/um/kernel/process_kern.c linux-2.6.0-test1/arch/um/kernel/process_kern.c
--- linux-2.6.0-test1-ori/arch/um/kernel/process_kern.c 2003-07-14 05:34:33.000000000 +0200
+++ linux-2.6.0-test1/arch/um/kernel/process_kern.c 2003-07-20 18:00:42.000000000 +0200
@@ -103,13 +103,13 @@ unsigned long alloc_stack(int order, int

 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 {
- struct task_struct *p;
-
+ long pid;
+
         current->thread.request.u.thread.proc = fn;
         current->thread.request.u.thread.arg = arg;
- p = do_fork(CLONE_VM | flags, 0, NULL, 0, NULL, NULL);
- if(IS_ERR(p)) panic("do_fork failed in kernel_thread");
- return(p->pid);
+ pid = do_fork(CLONE_VM | flags, 0, NULL, 0, NULL, NULL);
+ if (pid < 0) panic("do_fork failed in kernel_thread");
+ return (pid);
 }

 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
diff -Nrup linux-2.6.0-test1-ori/arch/um/kernel/smp.c linux-2.6.0-test1/arch/um/kernel/smp.c
--- linux-2.6.0-test1-ori/arch/um/kernel/smp.c 2003-07-14 05:31:57.000000000 +0200
+++ linux-2.6.0-test1/arch/um/kernel/smp.c 2003-07-20 17:58:20.000000000 +0200
@@ -135,13 +135,15 @@ static int idle_proc(void *cpup)

 static struct task_struct *idle_thread(int cpu)
 {
- struct task_struct *new_task;
         unsigned char c;
+ long new_pid;
+ struct task_struct *new_task;

         current->thread.request.u.thread.proc = idle_proc;
         current->thread.request.u.thread.arg = (void *) cpu;
- new_task = do_fork(CLONE_VM | CLONE_IDLETASK, 0, NULL, 0, NULL, NULL);
- if(IS_ERR(new_task)) panic("do_fork failed in idle_thread");
+ new_pid = do_fork(CLONE_VM | CLONE_IDLETASK, 0, NULL, 0, NULL, NULL);
+ if (new_pid < 0) panic("do_fork failed in idle_thread");
+ new_task = find_task_by_pid(new_pid);

         cpu_tasks[cpu] = ((struct cpu_task)
                           { .pid = new_task->thread.mode.tt.extern_pid,
diff -Nrup linux-2.6.0-test1-ori/arch/um/kernel/syscall_kern.c linux-2.6.0-test1/arch/um/kernel/syscall_kern.c
--- linux-2.6.0-test1-ori/arch/um/kernel/syscall_kern.c 2003-07-14 05:36:35.000000000 +0200
+++ linux-2.6.0-test1/arch/um/kernel/syscall_kern.c 2003-07-20 17:53:54.000000000 +0200
@@ -35,32 +35,32 @@ long um_mount(char * dev_name, char * di

 long sys_fork(void)
 {
- struct task_struct *p;
+ long pid;

         current->thread.forking = 1;
- p = do_fork(SIGCHLD, 0, NULL, 0, NULL, NULL);
+ pid = do_fork(SIGCHLD, 0, NULL, 0, NULL, NULL);
         current->thread.forking = 0;
- return(IS_ERR(p) ? PTR_ERR(p) : p->pid);
+ return pid;
 }

 long sys_clone(unsigned long clone_flags, unsigned long newsp)
 {
- struct task_struct *p;
+ long pid;

         current->thread.forking = 1;
- p = do_fork(clone_flags, newsp, NULL, 0, NULL, NULL);
+ pid = do_fork(clone_flags, newsp, NULL, 0, NULL, NULL);
         current->thread.forking = 0;
- return(IS_ERR(p) ? PTR_ERR(p) : p->pid);
+ return pid;
 }

 long sys_vfork(void)
 {
- struct task_struct *p;
+ long pid;

         current->thread.forking = 1;
- p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, NULL, 0, NULL, NULL);
+ pid = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, NULL, 0, NULL, NULL);
         current->thread.forking = 0;
- return(IS_ERR(p) ? PTR_ERR(p) : p->pid);
+ return pid;
 }

 /* common code for old and new mmaps */ 

-- 
Philippe Biondi <biondi@ cartel-securite.fr> Cartel Sécurité
Security Consultant/R&D                      http://www.cartel-securite.fr
PGP KeyID:3D9A43E2  FingerPrint:C40A772533730E39330DC0985EE8FF5F3D9A43E2

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This archive was generated by hypermail 2b29 : Wed Jul 23 2003 - 22:00:41 EST