aboutsummaryrefslogtreecommitdiff
path: root/tools/perf/util/demangle-rust.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /tools/perf/util/demangle-rust.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'tools/perf/util/demangle-rust.c')
-rw-r--r--tools/perf/util/demangle-rust.c269
1 files changed, 269 insertions, 0 deletions
diff --git a/tools/perf/util/demangle-rust.c b/tools/perf/util/demangle-rust.c
new file mode 100644
index 000000000..a659fc69f
--- /dev/null
+++ b/tools/perf/util/demangle-rust.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <string.h>
+#include "debug.h"
+
+#include "demangle-rust.h"
+
+/*
+ * Mangled Rust symbols look like this:
+ *
+ * _$LT$std..sys..fd..FileDesc$u20$as$u20$core..ops..Drop$GT$::drop::hc68340e1baa4987a
+ *
+ * The original symbol is:
+ *
+ * <std::sys::fd::FileDesc as core::ops::Drop>::drop
+ *
+ * The last component of the path is a 64-bit hash in lowercase hex, prefixed
+ * with "h". Rust does not have a global namespace between crates, an illusion
+ * which Rust maintains by using the hash to distinguish things that would
+ * otherwise have the same symbol.
+ *
+ * Any path component not starting with a XID_Start character is prefixed with
+ * "_".
+ *
+ * The following escape sequences are used:
+ *
+ * "," => $C$
+ * "@" => $SP$
+ * "*" => $BP$
+ * "&" => $RF$
+ * "<" => $LT$
+ * ">" => $GT$
+ * "(" => $LP$
+ * ")" => $RP$
+ * " " => $u20$
+ * "'" => $u27$
+ * "[" => $u5b$
+ * "]" => $u5d$
+ * "~" => $u7e$
+ *
+ * A double ".." means "::" and a single "." means "-".
+ *
+ * The only characters allowed in the mangled symbol are a-zA-Z0-9 and _.:$
+ */
+
+static const char *hash_prefix = "::h";
+static const size_t hash_prefix_len = 3;
+static const size_t hash_len = 16;
+
+static bool is_prefixed_hash(const char *start);
+static bool looks_like_rust(const char *sym, size_t len);
+static bool unescape(const char **in, char **out, const char *seq, char value);
+
+/*
+ * INPUT:
+ * sym: symbol that has been through BFD-demangling
+ *
+ * This function looks for the following indicators:
+ *
+ * 1. The hash must consist of "h" followed by 16 lowercase hex digits.
+ *
+ * 2. As a sanity check, the hash must use between 5 and 15 of the 16 possible
+ * hex digits. This is true of 99.9998% of hashes so once in your life you
+ * may see a false negative. The point is to notice path components that
+ * could be Rust hashes but are probably not, like "haaaaaaaaaaaaaaaa". In
+ * this case a false positive (non-Rust symbol has an important path
+ * component removed because it looks like a Rust hash) is worse than a
+ * false negative (the rare Rust symbol is not demangled) so this sets the
+ * balance in favor of false negatives.
+ *
+ * 3. There must be no characters other than a-zA-Z0-9 and _.:$
+ *
+ * 4. There must be no unrecognized $-sign sequences.
+ *
+ * 5. There must be no sequence of three or more dots in a row ("...").
+ */
+bool
+rust_is_mangled(const char *sym)
+{
+ size_t len, len_without_hash;
+
+ if (!sym)
+ return false;
+
+ len = strlen(sym);
+ if (len <= hash_prefix_len + hash_len)
+ /* Not long enough to contain "::h" + hash + something else */
+ return false;
+
+ len_without_hash = len - (hash_prefix_len + hash_len);
+ if (!is_prefixed_hash(sym + len_without_hash))
+ return false;
+
+ return looks_like_rust(sym, len_without_hash);
+}
+
+/*
+ * A hash is the prefix "::h" followed by 16 lowercase hex digits. The hex
+ * digits must comprise between 5 and 15 (inclusive) distinct digits.
+ */
+static bool is_prefixed_hash(const char *str)
+{
+ const char *end;
+ bool seen[16];
+ size_t i;
+ int count;
+
+ if (strncmp(str, hash_prefix, hash_prefix_len))
+ return false;
+ str += hash_prefix_len;
+
+ memset(seen, false, sizeof(seen));
+ for (end = str + hash_len; str < end; str++)
+ if (*str >= '0' && *str <= '9')
+ seen[*str - '0'] = true;
+ else if (*str >= 'a' && *str <= 'f')
+ seen[*str - 'a' + 10] = true;
+ else
+ return false;
+
+ /* Count how many distinct digits seen */
+ count = 0;
+ for (i = 0; i < 16; i++)
+ if (seen[i])
+ count++;
+
+ return count >= 5 && count <= 15;
+}
+
+static bool looks_like_rust(const char *str, size_t len)
+{
+ const char *end = str + len;
+
+ while (str < end)
+ switch (*str) {
+ case '$':
+ if (!strncmp(str, "$C$", 3))
+ str += 3;
+ else if (!strncmp(str, "$SP$", 4)
+ || !strncmp(str, "$BP$", 4)
+ || !strncmp(str, "$RF$", 4)
+ || !strncmp(str, "$LT$", 4)
+ || !strncmp(str, "$GT$", 4)
+ || !strncmp(str, "$LP$", 4)
+ || !strncmp(str, "$RP$", 4))
+ str += 4;
+ else if (!strncmp(str, "$u20$", 5)
+ || !strncmp(str, "$u27$", 5)
+ || !strncmp(str, "$u5b$", 5)
+ || !strncmp(str, "$u5d$", 5)
+ || !strncmp(str, "$u7e$", 5))
+ str += 5;
+ else
+ return false;
+ break;
+ case '.':
+ /* Do not allow three or more consecutive dots */
+ if (!strncmp(str, "...", 3))
+ return false;
+ /* Fall through */
+ case 'a' ... 'z':
+ case 'A' ... 'Z':
+ case '0' ... '9':
+ case '_':
+ case ':':
+ str++;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * INPUT:
+ * sym: symbol for which rust_is_mangled(sym) returns true
+ *
+ * The input is demangled in-place because the mangled name is always longer
+ * than the demangled one.
+ */
+void
+rust_demangle_sym(char *sym)
+{
+ const char *in;
+ char *out;
+ const char *end;
+
+ if (!sym)
+ return;
+
+ in = sym;
+ out = sym;
+ end = sym + strlen(sym) - (hash_prefix_len + hash_len);
+
+ while (in < end)
+ switch (*in) {
+ case '$':
+ if (!(unescape(&in, &out, "$C$", ',')
+ || unescape(&in, &out, "$SP$", '@')
+ || unescape(&in, &out, "$BP$", '*')
+ || unescape(&in, &out, "$RF$", '&')
+ || unescape(&in, &out, "$LT$", '<')
+ || unescape(&in, &out, "$GT$", '>')
+ || unescape(&in, &out, "$LP$", '(')
+ || unescape(&in, &out, "$RP$", ')')
+ || unescape(&in, &out, "$u20$", ' ')
+ || unescape(&in, &out, "$u27$", '\'')
+ || unescape(&in, &out, "$u5b$", '[')
+ || unescape(&in, &out, "$u5d$", ']')
+ || unescape(&in, &out, "$u7e$", '~'))) {
+ pr_err("demangle-rust: unexpected escape sequence");
+ goto done;
+ }
+ break;
+ case '_':
+ /*
+ * If this is the start of a path component and the next
+ * character is an escape sequence, ignore the
+ * underscore. The mangler inserts an underscore to make
+ * sure the path component begins with a XID_Start
+ * character.
+ */
+ if ((in == sym || in[-1] == ':') && in[1] == '$')
+ in++;
+ else
+ *out++ = *in++;
+ break;
+ case '.':
+ if (in[1] == '.') {
+ /* ".." becomes "::" */
+ *out++ = ':';
+ *out++ = ':';
+ in += 2;
+ } else {
+ /* "." becomes "-" */
+ *out++ = '-';
+ in++;
+ }
+ break;
+ case 'a' ... 'z':
+ case 'A' ... 'Z':
+ case '0' ... '9':
+ case ':':
+ *out++ = *in++;
+ break;
+ default:
+ pr_err("demangle-rust: unexpected character '%c' in symbol\n",
+ *in);
+ goto done;
+ }
+
+done:
+ *out = '\0';
+}
+
+static bool unescape(const char **in, char **out, const char *seq, char value)
+{
+ size_t len = strlen(seq);
+
+ if (strncmp(*in, seq, len))
+ return false;
+
+ **out = value;
+
+ *in += len;
+ *out += 1;
+
+ return true;
+}