On 17. 12. 24, 18:08, Greg Kroah-Hartman wrote:
6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Juergen Gross <jgross@xxxxxxxx>
commit 0ef8047b737d7480a5d4c46d956e97c190f13050 upstream.
Add static_call_update_early() for updating static-call targets in
very early boot.
This will be needed for support of Xen guest type specific hypercall
functions.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Co-developed-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Co-developed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/static_call.h | 15 +++++++++++++++
arch/x86/include/asm/sync_core.h | 6 +++---
arch/x86/kernel/static_call.c | 9 +++++++++
include/linux/compiler.h | 37 ++++++++++++++++++++++++++-----------
include/linux/static_call.h | 1 +
kernel/static_call_inline.c | 2 +-
6 files changed, 55 insertions(+), 15 deletions(-)
--- a/arch/x86/include/asm/static_call.h
+++ b/arch/x86/include/asm/static_call.h
@@ -65,4 +65,19 @@
extern bool __static_call_fixup(void *tramp, u8 op, void *dest);
+extern void __static_call_update_early(void *tramp, void *func);
+
+#define static_call_update_early(name, _func) \
+({ \
+ typeof(&STATIC_CALL_TRAMP(name)) __F = (_func); \
+ if (static_call_initialized) { \
+ __static_call_update(&STATIC_CALL_KEY(name), \
+ STATIC_CALL_TRAMP_ADDR(name), __F);\
+ } else { \
+ WRITE_ONCE(STATIC_CALL_KEY(name).func, _func); \
+ __static_call_update_early(STATIC_CALL_TRAMP_ADDR(name),\
+ __F); \
+ } \
+})
...
--- a/kernel/static_call_inline.c
+++ b/kernel/static_call_inline.c
@@ -15,7 +15,7 @@ extern struct static_call_site __start_s
extern struct static_call_tramp_key __start_static_call_tramp_key[],
__stop_static_call_tramp_key[];
-static int static_call_initialized;
+int static_call_initialized;
This breaks the build on i386:
ld: arch/x86/xen/enlighten.o: in function `__xen_hypercall_setfunc':
enlighten.c:(.noinstr.text+0x2a): undefined reference to `static_call_initialized'
ld: enlighten.c:(.noinstr.text+0x62): undefined reference to `static_call_initialized'
ld: arch/x86/kernel/static_call.o: in function `__static_call_update_early':
static_call.c:(.noinstr.text+0x15): undefined reference to `static_call_initialized'
kernel/static_call_inline.c containing this `static_call_initialized` is
not built there as:
HAVE_STATIC_CALL_INLINE=n
-> HAVE_OBJTOOL=n
-> X86_64=n
This is broken in upstream too.
thanks,
--
js
suse labs
