diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2021-06-24 11:41:23 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-09-17 13:20:26 +0200 |
| commit | db2b0c5d7b6f19b3c2cab08c531b65342eb5252b (patch) | |
| tree | 68e20b1e3dbf761d76ea9e8dbdfe2b2677bd29b5 /lib | |
| parent | 1462eb381b4c27576a3e818bc9f918765d327fdf (diff) | |
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')
| -rw-r--r-- | lib/Kconfig.debug | 2 |
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 |