The '.data..percpu..first' section, which contains the IRQ software
stack, is included in the percpu user-mapped data area.

The IRQ stack is a software stack which is switched to *after* the CR3
switch, so it doesn't make sense to map it in user space.

Unmap it, and make sure the user-mapped area is page-aligned so it can
be mapped cleanly.

Fixes: 7d1b4c99a605 ("x86/mm/kaiser: Introduce user-mapped per-CPU areas")
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
 include/asm-generic/vmlinux.lds.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h 
b/include/asm-generic/vmlinux.lds.h
index 386f8846d9e9..45d2fbb081c6 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -826,9 +826,9 @@
  */
 #define PERCPU_INPUT(cacheline)                                                
\
        VMLINUX_SYMBOL(__per_cpu_start) = .;                            \
-       VMLINUX_SYMBOL(__per_cpu_user_mapped_start) = .;                \
        *(.data..percpu..first)                                         \
-       . = ALIGN(cacheline);                                           \
+       . = ALIGN(PAGE_SIZE);                                           \
+       VMLINUX_SYMBOL(__per_cpu_user_mapped_start) = .;                \
        *(.data..percpu..user_mapped)                                   \
        *(.data..percpu..user_mapped..shared_aligned)                   \
        VMLINUX_SYMBOL(__per_cpu_user_mapped_end) = .;                  \
-- 
2.13.6

Reply via email to