MINSIGSTKSZ on ia32

MINSIGSTKSZ on ia32

[Arun Sharma]

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MINSIGSTKSZ is defined differently for i386 and ia64. This patch improves compatibility with apps which use sigaltstack(2) with sizes between MINSIGSTKSZ_IA32 and MINSIGSTKSZ.

Patches for both 2.4 and 2.6 are attached.

	-Arun


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Index: linux-2.4/arch/ia64/ia32/sys_ia32.c
===================================================================
--- linux-2.4/arch/ia64/ia32/sys_ia32.c	(revision 8)
+++ linux-2.4/arch/ia64/ia32/sys_ia32.c	(working copy)
@@ -75,6 +75,7 @@
 #define OFFSET4K(a)		((a) & 0xfff)
 #define PAGE_START(addr)	((addr) & PAGE_MASK)
 #define PAGE_OFF(addr)		((addr) & ~PAGE_MASK)
+#define MINSIGSTKSZ_IA32	2048
 
 extern asmlinkage long sys_execve (char *, char **, char **, struct pt_regs *);
 extern asmlinkage long sys_mprotect (unsigned long, size_t, unsigned long);
@@ -3408,10 +3409,18 @@
 			return -EFAULT;
 	uss.ss_sp = (void *) (long) buf32.ss_sp;
 	uss.ss_flags = buf32.ss_flags;
-	uss.ss_size = buf32.ss_size;
+	/* MINSIGSTKSZ is different for ia32 vs ia64. We lie here to pass the 
+           check and set it to the user requested value later */
+	if (buf32.ss_size < MINSIGSTKSZ_IA32) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	uss.ss_size = MINSIGSTKSZ;
 	set_fs(KERNEL_DS);
 	ret = do_sigaltstack(uss32 ? &uss : NULL, &uoss, pt->r12);
+ 	current->sas_ss_size = buf32.ss_size;	
 	set_fs(old_fs);
+out:
 	if (ret < 0)
 		return(ret);
 	if (uoss32) {

[-- Attachment #3: sigaltstk-2.6.patch --]
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Index: linux-2.6/arch/ia64/ia32/sys_ia32.c
===================================================================
--- linux-2.6/arch/ia64/ia32/sys_ia32.c	(revision 13148)
+++ linux-2.6/arch/ia64/ia32/sys_ia32.c	(working copy)
@@ -76,6 +76,7 @@
 
 #define OFFSET4K(a)		((a) & 0xfff)
 #define PAGE_START(addr)	((addr) & PAGE_MASK)
+#define MINSIGSTKSZ_IA32	2048
 
 #define high2lowuid(uid) ((uid) > 65535 ? 65534 : (uid))
 #define high2lowgid(gid) ((gid) > 65535 ? 65534 : (gid))
@@ -2262,10 +2263,18 @@
 			return -EFAULT;
 	uss.ss_sp = (void *) (long) buf32.ss_sp;
 	uss.ss_flags = buf32.ss_flags;
-	uss.ss_size = buf32.ss_size;
+	/* MINSIGSTKSZ is different for ia32 vs ia64. We lie here to pass the 
+           check and set it to the user requested value later */
+	if (buf32.ss_size < MINSIGSTKSZ_IA32) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	uss.ss_size = MINSIGSTKSZ;
 	set_fs(KERNEL_DS);
 	ret = do_sigaltstack(uss32 ? &uss : NULL, &uoss, pt->r12);
+ 	current->sas_ss_size = buf32.ss_size;	
 	set_fs(old_fs);
+out:
 	if (ret < 0)
 		return(ret);
 	if (uoss32) {

Re: MINSIGSTKSZ on ia32

[Bjorn Helgaas]

On Monday 08 September 2003 5:56 pm, Arun Sharma wrote:
> 
> MINSIGSTKSZ is defined differently for i386 and ia64. This patch improves compatibility with apps which use sigaltstack(2) with sizes between MINSIGSTKSZ_IA32 and MINSIGSTKSZ.
> 
> Patches for both 2.4 and 2.6 are attached.

I applied this for 2.4, thanks.