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authorPeter Zijlstra <peterz@infradead.org>2021-06-24 12:41:23 +0300
committerPeter Zijlstra <peterz@infradead.org>2021-09-17 14:20:26 +0300
commitdb2b0c5d7b6f19b3c2cab08c531b65342eb5252b (patch)
tree68e20b1e3dbf761d76ea9e8dbdfe2b2677bd29b5 /lib/Kconfig.debug
parent1462eb381b4c27576a3e818bc9f918765d327fdf (diff)
downloadlinux-db2b0c5d7b6f19b3c2cab08c531b65342eb5252b.tar.xz
objtool: Support pv_opsindirect calls for noinstr
Normally objtool will now follow indirect calls; there is no need. However, this becomes a problem with noinstr validation; if there's an indirect call from noinstr code, we very much need to know it is to another noinstr function. Luckily there aren't many indirect calls in entry code with the obvious exception of paravirt. As such, noinstr validation didn't work with paravirt kernels. In order to track pv_ops[] call targets, objtool reads the static pv_ops[] tables as well as direct assignments to the pv_ops[] array, provided the compiler makes them a single instruction like: bf87: 48 c7 05 00 00 00 00 00 00 00 00 movq $0x0,0x0(%rip) bf92 <xen_init_spinlocks+0x5f> bf8a: R_X86_64_PC32 pv_ops+0x268 There are, as of yet, no warnings for when this goes wrong :/ Using the functions found with the above means, all pv_ops[] calls are now subject to noinstr validation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210624095149.118815755@infradead.org
Diffstat (limited to 'lib/Kconfig.debug')
-rw-r--r--lib/Kconfig.debug2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ed4a31e34098..63a4735cef66 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -458,7 +458,7 @@ config STACK_VALIDATION
config VMLINUX_VALIDATION
bool
- depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
+ depends on STACK_VALIDATION && DEBUG_ENTRY
default y
config VMLINUX_MAP