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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-05-23 19:22:09 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-25 17:17:33 +0300 |
commit | c1a35f5ddf369ed50bd46bf53d1c54697781317f (patch) | |
tree | c21b8db110fc0f17e41847860d806ad608565760 /arch/s390/net/bpf_jit.S | |
parent | 457b944b61e6f192c8a6136451cce5ca0aa92027 (diff) | |
download | linux-c1a35f5ddf369ed50bd46bf53d1c54697781317f.tar.xz |
s390: use expoline thunks in the BPF JIT
[ Upstream commit de5cb6eb514ebe241e3edeb290cb41deb380b81d ]
The BPF JIT need safe guarding against spectre v2 in the sk_load_xxx
assembler stubs and the indirect branches generated by the JIT itself
need to be converted to expolines.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390/net/bpf_jit.S')
-rw-r--r-- | arch/s390/net/bpf_jit.S | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/s390/net/bpf_jit.S b/arch/s390/net/bpf_jit.S index 25bb4643c4f4..9f794869c1b0 100644 --- a/arch/s390/net/bpf_jit.S +++ b/arch/s390/net/bpf_jit.S @@ -9,6 +9,7 @@ */ #include <linux/linkage.h> +#include <asm/nospec-insn.h> #include "bpf_jit.h" /* @@ -54,7 +55,7 @@ ENTRY(sk_load_##NAME##_pos); \ clg %r3,STK_OFF_HLEN(%r15); /* Offset + SIZE > hlen? */ \ jh sk_load_##NAME##_slow; \ LOAD %r14,-SIZE(%r3,%r12); /* Get data from skb */ \ - b OFF_OK(%r6); /* Return */ \ + B_EX OFF_OK,%r6; /* Return */ \ \ sk_load_##NAME##_slow:; \ lgr %r2,%r7; /* Arg1 = skb pointer */ \ @@ -64,11 +65,14 @@ sk_load_##NAME##_slow:; \ brasl %r14,skb_copy_bits; /* Get data from skb */ \ LOAD %r14,STK_OFF_TMP(%r15); /* Load from temp bufffer */ \ ltgr %r2,%r2; /* Set cc to (%r2 != 0) */ \ - br %r6; /* Return */ + BR_EX %r6; /* Return */ sk_load_common(word, 4, llgf) /* r14 = *(u32 *) (skb->data+offset) */ sk_load_common(half, 2, llgh) /* r14 = *(u16 *) (skb->data+offset) */ + GEN_BR_THUNK %r6 + GEN_B_THUNK OFF_OK,%r6 + /* * Load 1 byte from SKB (optimized version) */ @@ -80,7 +84,7 @@ ENTRY(sk_load_byte_pos) clg %r3,STK_OFF_HLEN(%r15) # Offset >= hlen? jnl sk_load_byte_slow llgc %r14,0(%r3,%r12) # Get byte from skb - b OFF_OK(%r6) # Return OK + B_EX OFF_OK,%r6 # Return OK sk_load_byte_slow: lgr %r2,%r7 # Arg1 = skb pointer @@ -90,7 +94,7 @@ sk_load_byte_slow: brasl %r14,skb_copy_bits # Get data from skb llgc %r14,STK_OFF_TMP(%r15) # Load result from temp buffer ltgr %r2,%r2 # Set cc to (%r2 != 0) - br %r6 # Return cc + BR_EX %r6 # Return cc #define sk_negative_common(NAME, SIZE, LOAD) \ sk_load_##NAME##_slow_neg:; \ @@ -104,7 +108,7 @@ sk_load_##NAME##_slow_neg:; \ jz bpf_error; \ LOAD %r14,0(%r2); /* Get data from pointer */ \ xr %r3,%r3; /* Set cc to zero */ \ - br %r6; /* Return cc */ + BR_EX %r6; /* Return cc */ sk_negative_common(word, 4, llgf) sk_negative_common(half, 2, llgh) @@ -113,4 +117,4 @@ sk_negative_common(byte, 1, llgc) bpf_error: # force a return 0 from jit handler ltgr %r15,%r15 # Set condition code - br %r6 + BR_EX %r6 |