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authorJason Wessel <jason.wessel@windriver.com>2010-11-15 08:07:35 -0600
committerJason Wessel <jason.wessel@windriver.com>2010-11-17 13:54:57 -0600
commit10a6e67648d4b47769953bd24759ba9609bf00df (patch)
tree87a7381db182f858bda6b275c421ee01f674b5de /arch/x86/kernel/kgdb.c
parent5450d904054b4ed582793ad6ecb5469f03cc4c46 (diff)
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kgdb,x86: fix regression in detach handling
The fix from ba773f7c510c0b252145933926c636c439889207 (x86,kgdb: Fix hw breakpoint regression) was not entirely complete. The kgdb_remove_all_hw_break() function also needs to call the hw_break_release_slot() or else a breakpoint can get activated again after the debugger has detached. The kgdb test suite exposes the behavior in the form of either a hang or repetitive failure. The kernel config that exposes the problem contains all of the following: CONFIG_DEBUG_RODATA=y CONFIG_KGDB_TESTS=y CONFIG_KGDB_TESTS_ON_BOOT=y CONFIG_KGDB_TESTS_BOOT_STRING="V1F100" Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Tested-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'arch/x86/kernel/kgdb.c')
-rw-r--r--arch/x86/kernel/kgdb.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index ec592caac4b4..cd21b654dec6 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -315,14 +315,18 @@ static void kgdb_remove_all_hw_break(void)
if (!breakinfo[i].enabled)
continue;
bp = *per_cpu_ptr(breakinfo[i].pev, cpu);
- if (bp->attr.disabled == 1)
+ if (!bp->attr.disabled) {
+ arch_uninstall_hw_breakpoint(bp);
+ bp->attr.disabled = 1;
continue;
+ }
if (dbg_is_early)
early_dr7 &= ~encode_dr7(i, breakinfo[i].len,
breakinfo[i].type);
- else
- arch_uninstall_hw_breakpoint(bp);
- bp->attr.disabled = 1;
+ else if (hw_break_release_slot(i))
+ printk(KERN_ERR "KGDB: hw bpt remove failed %lx\n",
+ breakinfo[i].addr);
+ breakinfo[i].enabled = 0;
}
}