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| author | Siddha, Suresh B <suresh.b.siddha@intel.com> | 2007-10-19 22:35:02 +0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-19 22:35:02 +0400 |
| commit | 957ff882f9db86e017f730e77322ec5193178e5e (patch) | |
| tree | 4db49853a5191bf8a91825ac50125f8b411ce4ea /arch/x86/kernel/vsyscall_64.c | |
| parent | f322727b92957ccd4b0366dbd42908613222033a (diff) | |
| download | linux-957ff882f9db86e017f730e77322ec5193178e5e.tar.xz | |
x86, vsyscall: fix the oops crash with __pa_vsymbol()
Appended patch fixes an oops while changing the vsyscall sysctl.
I am sure no one tested this code before integrating into mainline :(
BTW, using ioremap() in vsyscall_sysctl_change() to get the virtual
address of a kernel symbol sounds like an over kill.. I wonder if we
can define a simple __va_vsymbol() which will return directly the
kernel direct mapping. comments in the code which says gcc has trouble
with __va(__pa()) sounds bogus to me. __pa() on a vsyscall address will
not work anyhow :(
And also, the whole nop out syscall in vsyscall page infrastructure
(vsyscall_sysctl_change()) is added to make some attacks difficult,
and yet I don't see this nop out being done by default. This area
requires more cleanups?
Fix an oops with __pa_vsymbol(). VSYSCALL_FIRST_PAGE is a fixmap index.
We want the starting virtual address of the vsyscall page and not the index.
[ mingo: arch/x86 adaptation ]
Reported-by: Yanmin Zhang <yanmin.zhang@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/vsyscall_64.c')
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 585541ca1a7e..4a2c340ab0f3 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -48,7 +48,7 @@ ({unsigned long v; \ extern char __vsyscall_0; \ asm("" : "=r" (v) : "0" (x)); \ - ((v - VSYSCALL_FIRST_PAGE) + __pa_symbol(&__vsyscall_0)); }) + ((v - VSYSCALL_START) + __pa_symbol(&__vsyscall_0)); }) /* * vsyscall_gtod_data contains data that is : |