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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-12-20 16:38:25 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-02-07 21:03:11 +1100 |
| commit | c75388a8ceffbf1bf72c61afe66a72e58aa20c74 (patch) | |
| tree | bfdec3f718bb37032ecec137e0558eb6791a44cd | |
| parent | d95bf254be5f74c1e4c8f7cb64e2e21b9cc91717 (diff) | |
| download | linux-c75388a8ceffbf1bf72c61afe66a72e58aa20c74.tar.bz2 | |
powerpc/ftrace: Prepare PPC64's ftrace_caller() for CONFIG_DYNAMIC_FTRACE_WITH_ARGS
In order to implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS, change ftrace_caller()
to handle LIVEPATCH the same way as frace_caller_regs().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/850817333cc76593699032e8e9a70d8c36e1af1e.1640017960.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index d636fc755f60..f6f787819273 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -172,14 +172,19 @@ _GLOBAL(ftrace_caller) addi r3, r3, function_trace_op@toc@l ld r5, 0(r3) +#ifdef CONFIG_LIVEPATCH_64 + SAVE_GPR(14, r1) + mr r14,r7 /* remember old NIP */ +#endif /* Calculate ip from nip-4 into r3 for call below */ subi r3, r7, MCOUNT_INSN_SIZE /* Put the original return address in r4 as parent_ip */ + std r0, _LINK(r1) mr r4, r0 - /* Set pt_regs to NULL */ - li r6, 0 + /* Load &pt_regs in r6 for call below */ + addi r6, r1 ,STACK_FRAME_OVERHEAD /* ftrace_call(r3, r4, r5, r6) */ .globl ftrace_call @@ -189,6 +194,10 @@ ftrace_call: ld r3, _NIP(r1) mtctr r3 +#ifdef CONFIG_LIVEPATCH_64 + cmpd r14, r3 /* has NIP been altered? */ + REST_GPR(14, r1) +#endif /* Restore gprs */ REST_GPRS(3, 10, r1) @@ -196,13 +205,17 @@ ftrace_call: /* Restore callee's TOC */ ld r2, 24(r1) + /* Restore possibly modified LR */ + ld r0, _LINK(r1) + mtlr r0 + /* Pop our stack frame */ addi r1, r1, SWITCH_FRAME_SIZE - /* Reload original LR */ - ld r0, LRSAVE(r1) - mtlr r0 - +#ifdef CONFIG_LIVEPATCH_64 + /* Based on the cmpd above, if the NIP was altered handle livepatch */ + bne- livepatch_handler +#endif /* Handle function_graph or go back */ b ftrace_caller_common |