Re: Regression in ptrace (Wine) starting with 2.6.33-rc1

[Frederic Weisbecker <fweisbec@gmail.com>]

On Sun, Feb 14, 2010 at 09:13:06PM +0100, Michael Stefaniuc wrote:
> Although Wine will map address 0x0 for DOS programs that isn't the  
> reason for those tests. Wine has to support games that come with  
> pointless copy protection schemes that employ that technique.


Ah, which kind of protection?



> Cool, thanks!
> Any chance to get that fix into 2.6.33?


Yeah.

Could you please test the following patch on top of
2.6.33-rc9 ?
I'm trying to build wine but it fails because my libx11 is
incorrect for the linking (probably because I don't have a x86-32
version of libx11.so):

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 05d5fec..bb6006e 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -212,25 +212,6 @@ static int arch_check_va_in_kernelspace(unsigned long va, u8 hbp_len)
 	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
 }
 
-/*
- * Store a breakpoint's encoded address, length, and type.
- */
-static int arch_store_info(struct perf_event *bp)
-{
-	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-	/*
-	 * For kernel-addresses, either the address or symbol name can be
-	 * specified.
-	 */
-	if (info->name)
-		info->address = (unsigned long)
-				kallsyms_lookup_name(info->name);
-	if (info->address)
-		return 0;
-
-	return -EINVAL;
-}
-
 int arch_bp_generic_fields(int x86_len, int x86_type,
 			   int *gen_len, int *gen_type)
 {
@@ -362,10 +343,13 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp,
 		return ret;
 	}
 
-	ret = arch_store_info(bp);
-
-	if (ret < 0)
-		return ret;
+	/*
+	 * For kernel-addresses, either the address or symbol name can be
+	 * specified.
+	 */
+	if (info->name)
+		info->address = (unsigned long)
+				kallsyms_lookup_name(info->name);
 	/*
 	 * Check that the low-order bits of the address are appropriate
 	 * for the alignment implied by len.



> I cannot test that as the corresponding test is directly affected by  
> this ABI change.


Sure, let's fix the first problem to begin.

Thanks!