| Message ID | 20220630071441.28576-3-jgross@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 38fa5479b41376dc9d7f57e71c83514285a25ca0 |
| Headers | show |
| Series | x86: fix brk area initialization | expand |
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index e7e233209a8c..6a3cfaf6b72a 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -430,6 +430,8 @@ void __init clear_bss(void) { memset(__bss_start, 0, (unsigned long) __bss_stop - (unsigned long) __bss_start); + memset(__brk_base, 0, + (unsigned long) __brk_limit - (unsigned long) __brk_base); } static unsigned long get_cmd_line_ptr(void)
The .brk section has the same properties as .bss: it is an alloc-only section and should be cleared before being used. Not doing so is especially a problem for Xen PV guests, as the hypervisor will validate page tables (check for writable page tables and hypervisor private bits) before accepting them to be used. Make sure .brk is initially zero by letting clear_bss() clear the brk area, too. Signed-off-by: Juergen Gross <jgross@suse.com> --- arch/x86/kernel/head64.c | 2 ++ 1 file changed, 2 insertions(+)