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| author | Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com> | 2011-12-06 12:58:14 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-12-06 13:02:38 +0400 |
| commit | 1cf8343f55525c09c88da0a494a96e1b034f84e2 (patch) | |
| tree | 5cb45ead7d10d3021fd2a9424c47d25eefa4201f /drivers/lguest | |
| parent | cc3a1bf52a9d2808c7cd6e8f413b02b650b6b84b (diff) | |
| download | linux-1cf8343f55525c09c88da0a494a96e1b034f84e2.tar.xz | |
x86: Fix rflags in FAKE_STACK_FRAME
The x86_64 kernel pushes the fake kernel stack in
arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and
rflags register in it does not conform to the specification.
Although Intel's manual[1] says bit 1 of it shall be set to 1,
this bit is cleared to 0 on pushing the fake stack.
[1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual
Vol.1 3-21 Figure 3-8. EFLAGS Register
If it is not on purpose, it is better to be fixed, because
it can lead some tools misunderstanding the stack frame. For example,
"crash" utility[2] actually detects it and warns you like
below:
RIP: ffffffff8005dfa2 RSP: ffff8104ce0c7f58 RFLAGS: 00000200
[...]
bt: WARNING: possibly bogus exception frame
Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com>
Tested-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/lguest')
| -rw-r--r-- | drivers/lguest/x86/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 65af42f2d593..39809035320a 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -697,7 +697,7 @@ void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start) * interrupts are enabled. We always leave interrupts enabled while * running the Guest. */ - regs->eflags = X86_EFLAGS_IF | 0x2; + regs->eflags = X86_EFLAGS_IF | X86_EFLAGS_BIT1; /* * The "Extended Instruction Pointer" register says where the Guest is |