Add some diagnostics when TLS operations on the host fail. Also spit
out more information about the TLS environment on the host at boot
time.
Signed-off-by: Jeff Dike <[email protected]>
---
arch/um/sys-i386/tls.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
Index: linux-2.6.22/arch/um/sys-i386/tls.c
===================================================================
--- linux-2.6.22.orig/arch/um/sys-i386/tls.c 2007-11-14 14:08:50.000000000 -0500
+++ linux-2.6.22/arch/um/sys-i386/tls.c 2007-11-14 14:19:02.000000000 -0500
@@ -26,6 +26,11 @@ int do_set_thread_area(struct user_desc
cpu = get_cpu();
ret = os_set_thread_area(info, userspace_pid[cpu]);
put_cpu();
+
+ if (ret)
+ printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
+ "index = %d\n", ret, info->entry_number);
+
return ret;
}
@@ -37,6 +42,11 @@ int do_get_thread_area(struct user_desc
cpu = get_cpu();
ret = os_get_thread_area(info, userspace_pid[cpu]);
put_cpu();
+
+ if (ret)
+ printk(KERN_ERR "PTRACE_GET_THREAD_AREA failed, err = %d, "
+ "index = %d\n", ret, info->entry_number);
+
return ret;
}
@@ -356,10 +366,9 @@ out:
return ret;
}
-
/*
- * XXX: This part is probably common to i386 and x86-64. Don't create a common
- * file for now, do that when implementing x86-64 support.
+ * This code is really i386-only, but it detects and logs x86_64 GDT indexes
+ * if a 32-bit UML is running on a 64-bit host.
*/
static int __init __setup_host_supports_tls(void)
{
@@ -368,13 +377,16 @@ static int __init __setup_host_supports_
printk(KERN_INFO "Host TLS support detected\n");
printk(KERN_INFO "Detected host type: ");
switch (host_gdt_entry_tls_min) {
- case GDT_ENTRY_TLS_MIN_I386:
- printk("i386\n");
- break;
- case GDT_ENTRY_TLS_MIN_X86_64:
- printk("x86_64\n");
- break;
+ case GDT_ENTRY_TLS_MIN_I386:
+ printk(KERN_CONT "i386");
+ break;
+ case GDT_ENTRY_TLS_MIN_X86_64:
+ printk(KERN_CONT "x86_64");
+ break;
}
+ printk(KERN_CONT " (GDT indexes %d to %d)\n",
+ host_gdt_entry_tls_min,
+ host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES);
} else
printk(KERN_ERR " Host TLS support NOT detected! "
"TLS support inside UML will not work\n");