diff options
Diffstat (limited to 'usr/src/lib/libdtrace/common/dt_print.c')
| -rw-r--r-- | usr/src/lib/libdtrace/common/dt_print.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/usr/src/lib/libdtrace/common/dt_print.c b/usr/src/lib/libdtrace/common/dt_print.c index b71eddbf9d..4b4a23b199 100644 --- a/usr/src/lib/libdtrace/common/dt_print.c +++ b/usr/src/lib/libdtrace/common/dt_print.c @@ -27,6 +27,7 @@ */ /* * Copyright (c) 2013, Joyent, Inc. All rights reserved. + * Copyright 2022 Oxide Computer Company */ /* @@ -41,13 +42,13 @@ * * This implementation differs from MDB's in the following ways: * - * - We do not expose any options or flags. The behavior of print() is + * - We do not expose any options or flags. The behavior of print() is * equivalent to "::print -tn". * - * - MDB will display "holes" in structures (unused padding between + * - MDB will display "holes" in structures (unused padding between * members). * - * - When printing arrays of structures, MDB will leave a trailing ',' + * - When printing arrays of structures, MDB will leave a trailing ',' * after the last element. * * - MDB will print time_t types as date and time. @@ -149,7 +150,8 @@ dt_print_indent(dt_printarg_t *pap) * Print a bitfield. It's worth noting that the D compiler support for * bitfields is currently broken; printing "D`user_desc_t" (pulled in by the * various D provider files) will produce incorrect results compared to - * "genunix`user_desc_t". + * "genunix`user_desc_t". However, bitfields that are built via CTF will be + * fine. Note, this is derived from mdb's print_bifield in mdb_print.c. */ static void print_bitfield(dt_printarg_t *pap, ulong_t off, ctf_encoding_t *ep) @@ -158,11 +160,32 @@ print_bitfield(dt_printarg_t *pap, ulong_t off, ctf_encoding_t *ep) caddr_t addr = pap->pa_addr + off / NBBY; uint64_t mask = (1ULL << ep->cte_bits) - 1; uint64_t value = 0; - size_t size = (ep->cte_bits + (NBBY - 1)) / NBBY; uint8_t *buf = (uint8_t *)&value; uint8_t shift; /* + * Our bitfield may straddle a byte boundary. We explicitly take the + * offset of the bitfield within its byte into account when determining + * the overall amount of data to copy and mask off from the underlying + * data. + */ + uint_t nbits = ep->cte_bits + (off % NBBY); + size_t size = P2ROUNDUP(nbits, NBBY) / NBBY; + + /* + * The resulting size must fit within the 64-bit value that we're using + * to store the value, otherwise the bcopy below could destroy our + * stack. This could be handled, but is not practically worth + * addressing. This choice apes mdb, so if you're considering fixing + * this, fix mdb as well. + */ + if (size > sizeof (value)) { + (void) fprintf(fp, "??? (total bitfield too large after " + "alignment"); + return; + } + + /* * On big-endian machines, we need to adjust the buf pointer to refer * to the lowest 'size' bytes in 'value', and we need to shift based on * the offset from the end of the data, not the offset of the start. @@ -248,12 +271,8 @@ dt_print_int(ctf_id_t base, ulong_t off, dt_printarg_t *pap) return; } - /* - * We print this as a bitfield if the bit encoding indicates it's not - * an even power of two byte size, or is larger than 8 bytes. - */ size = e.cte_bits / NBBY; - if (size > 8 || (e.cte_bits % NBBY) != 0 || (size & (size - 1)) != 0) { + if (dt_is_bitfield(&e, off)) { print_bitfield(pap, off, &e); return; } @@ -341,7 +360,7 @@ dt_print_ptr(ctf_id_t base, ulong_t off, dt_printarg_t *pap) * each member, and recursively invoke ctf_type_visit() for each member. If * the members are non-structs, then we print them out directly: * - * [ 0x14, 0x2e, 0 ] + * [ 0x14, 0x2e, 0 ] * * If they are structs, then we print out the necessary leading and trailing * braces, to end up with: @@ -408,7 +427,7 @@ dt_print_array(ctf_id_t base, ulong_t off, dt_printarg_t *pap) * don't bother printing out the brackets. This lets print("foo") look * like: * - * string "foo" + * string "foo" * * As D will internally represent this as a char[256] array. */ |