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| author | Ingo Molnar <mingo@elte.hu> | 2008-12-24 12:49:51 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-24 12:49:51 +0300 |
| commit | 40f15ad8aadff5ebb621b17a6f303ad2cd3f847d (patch) | |
| tree | 0496814ac18a6d6eb7302fab26fe77dd022955b7 | |
| parent | 280a9ca5d0663b185ddc4443052076c29652a328 (diff) | |
| download | linux-40f15ad8aadff5ebb621b17a6f303ad2cd3f847d.tar.xz | |
x86: disable X86_PTRACE_BTS
there's a new ptrace arch level feature in .28:
config X86_PTRACE_BTS
bool "Branch Trace Store"
it has broken fork() handling: the old DS area gets copied over into
a new task without clearing it.
Fixes exist but they came too late:
c5dee61: x86, bts: memory accounting
bf53de9: x86, bts: add fork and exit handling
and are queued up for v2.6.29. This shows that the facility is still not
tested well enough to release into a stable kernel - disable it for now and
reactivate in .29. In .29 the hardware-branch-tracer will use the DS/BTS
facilities too - hopefully resulting in better code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/Kconfig.cpu | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index b815664fe370..8e99073b9e0f 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -520,6 +520,7 @@ config X86_PTRACE_BTS bool "Branch Trace Store" default y depends on X86_DEBUGCTLMSR + depends on BROKEN help This adds a ptrace interface to the hardware's branch trace store. |