[PATCH v5 7/7] powerpc/64s: Blacklist rtas entry/exit from kprobes
From: Naveen N. Rao <hidden>
Date: 2017-06-29 17:50:26
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
We can't take traps with relocation off, so blacklist enter_rtas() and rtas_return_loc(). However, instead of blacklisting all of enter_rtas(), introduce a new symbol __enter_rtas from where on we can't take a trap and blacklist that. Signed-off-by: Naveen N. Rao <redacted> --- arch/powerpc/kernel/entry_64.S | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d1690ccfde0a..dc93452fb1fa 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S@@ -1090,6 +1090,8 @@ _GLOBAL(enter_rtas) rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG) ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE andc r6,r0,r9 + +__enter_rtas: sync /* disable interrupts so SRR0/1 */ mtmsrd r0 /* don't get trashed */
@@ -1126,6 +1128,8 @@ rtas_return_loc: mtspr SPRN_SRR1,r4 rfid b . /* prevent speculative execution */ +_ASM_NOKPROBE_SYMBOL(__enter_rtas) +_ASM_NOKPROBE_SYMBOL(rtas_return_loc) .align 3 1: .llong rtas_restore_regs
--
2.13.1