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From: "Alex Bennée" <alex.bennee@linaro.org>
To: peter.maydell@linaro.org
Cc: "Richard Henderson" <richard.henderson@linaro.org>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	qemu-devel@nongnu.org
Subject: [PULL v2 55/73] plugin: add qemu_plugin_insn_disas helper
Date: Fri, 25 Oct 2019 07:36:55 +0100
Message-ID: <20191025063713.23374-56-alex.bennee@linaro.org> (raw)
In-Reply-To: <20191025063713.23374-1-alex.bennee@linaro.org>

Give the plugins access to the QEMU dissasembler so they don't have to
re-invent the wheel. We generate a warning when there are spare bytes
in the decode buffer. This is usually due to the front end loading in
more bytes than decoded.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/disas.c b/disas.c
index 3e2bfa572b1..3937da61571 100644
--- a/disas.c
+++ b/disas.c
@@ -418,6 +418,7 @@ static bool cap_disas_monitor(disassemble_info *info, uint64_t pc, int count)
 # define cap_disas_target(i, p, s)  false
 # define cap_disas_host(i, p, s)  false
 # define cap_disas_monitor(i, p, c)  false
+# define cap_disas_plugin(i, p, c) false
 #endif /* CONFIG_CAPSTONE */
 
 /* Disassemble this for me please... (debugging).  */
@@ -475,6 +476,115 @@ void target_disas(FILE *out, CPUState *cpu, target_ulong code,
     }
 }
 
+static __thread GString plugin_disas_output;
+
+static int plugin_printf(FILE *stream, const char *fmt, ...)
+{
+    va_list va;
+    GString *s = &plugin_disas_output;
+    int initial_len = s->len;
+
+    va_start(va, fmt);
+    g_string_append_vprintf(s, fmt, va);
+    va_end(va);
+
+    return s->len - initial_len;
+}
+
+static void plugin_print_address(bfd_vma addr, struct disassemble_info *info)
+{
+    /* does nothing */
+}
+
+
+#ifdef CONFIG_CAPSTONE
+/* Disassemble a single instruction directly into plugin output */
+static
+bool cap_disas_plugin(disassemble_info *info, uint64_t pc, size_t size)
+{
+    uint8_t cap_buf[1024];
+    csh handle;
+    cs_insn *insn;
+    size_t csize = 0;
+    int count;
+    GString *s = &plugin_disas_output;
+
+    if (cap_disas_start(info, &handle) != CS_ERR_OK) {
+        return false;
+    }
+    insn = cap_insn;
+
+    size_t tsize = MIN(sizeof(cap_buf) - csize, size);
+    const uint8_t *cbuf = cap_buf;
+    target_read_memory(pc, cap_buf, tsize, info);
+
+    count = cs_disasm(handle, cbuf, size, 0, 1, &insn);
+
+    if (count) {
+        g_string_printf(s, "%s %s", insn->mnemonic, insn->op_str);
+    } else {
+        g_string_printf(s, "cs_disasm failed");
+    }
+
+    cs_close(&handle);
+    return true;
+}
+#endif
+
+/*
+ * We should only be dissembling one instruction at a time here. If
+ * there is left over it usually indicates the front end has read more
+ * bytes than it needed.
+ */
+char *plugin_disas(CPUState *cpu, uint64_t addr, size_t size)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+    int count;
+    CPUDebug s;
+    GString *ds = g_string_set_size(&plugin_disas_output, 0);
+
+    g_assert(ds == &plugin_disas_output);
+
+    INIT_DISASSEMBLE_INFO(s.info, NULL, plugin_printf);
+
+    s.cpu = cpu;
+    s.info.read_memory_func = target_read_memory;
+    s.info.buffer_vma = addr;
+    s.info.buffer_length = size;
+    s.info.print_address_func = plugin_print_address;
+    s.info.cap_arch = -1;
+    s.info.cap_mode = 0;
+    s.info.cap_insn_unit = 4;
+    s.info.cap_insn_split = 4;
+
+#ifdef TARGET_WORDS_BIGENDIAN
+    s.info.endian = BFD_ENDIAN_BIG;
+#else
+    s.info.endian = BFD_ENDIAN_LITTLE;
+#endif
+
+    if (cc->disas_set_info) {
+        cc->disas_set_info(cpu, &s.info);
+    }
+
+    if (s.info.cap_arch >= 0 && cap_disas_plugin(&s.info, addr, size)) {
+        return g_strdup(ds->str);
+    }
+
+    if (s.info.print_insn == NULL) {
+        s.info.print_insn = print_insn_od_target;
+    }
+
+    count = s.info.print_insn(addr, &s.info);
+
+    /* The decoder probably read more than it needed it's not critical */
+    if (count < size) {
+        warn_report("%s: %zu bytes left over", __func__, size - count);
+    }
+
+    return g_strdup(ds->str);
+}
+
 /* Disassemble this for me please... (debugging). */
 void disas(FILE *out, void *code, unsigned long size)
 {
diff --git a/include/disas/disas.h b/include/disas/disas.h
index ba47e9197cd..36c33f6f194 100644
--- a/include/disas/disas.h
+++ b/include/disas/disas.h
@@ -14,6 +14,8 @@ void target_disas(FILE *out, CPUState *cpu, target_ulong code,
 void monitor_disas(Monitor *mon, CPUState *cpu,
                    target_ulong pc, int nb_insn, int is_physical);
 
+char *plugin_disas(CPUState *cpu, uint64_t addr, size_t size);
+
 /* Look up symbol for debugging purpose.  Returns "" if unknown. */
 const char *lookup_symbol(target_ulong orig_addr);
 #endif
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 784f1dfc3da..ddf267fbfe0 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -351,6 +351,15 @@ qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
                                          qemu_plugin_vcpu_syscall_ret_cb_t cb);
 
 
+/**
+ * qemu_plugin_insn_disas() - return disassembly string for instruction
+ * @insn: instruction reference
+ *
+ * Returns an allocated string containing the disassembly
+ */
+
+char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn);
+
 /**
  * qemu_plugin_vcpu_for_each() - iterate over the existing vCPU
  * @id: plugin ID
diff --git a/plugins/api.c b/plugins/api.c
index 33dac8e790d..5adc4d25a1e 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -39,7 +39,8 @@
 #include "cpu.h"
 #include "sysemu/sysemu.h"
 #include "tcg/tcg.h"
-#include "trace/mem-internal.h" /* mem_info macros */
+#include "exec/exec-all.h"
+#include "disas/disas.h"
 #include "plugin.h"
 #ifndef CONFIG_USER_ONLY
 #include "qemu/plugin-memory.h"
@@ -212,6 +213,12 @@ void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
     return insn->haddr;
 }
 
+char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
+{
+    CPUState *cpu = current_cpu;
+    return plugin_disas(cpu, insn->vaddr, insn->data->len);
+}
+
 /*
  * The memory queries allow the plugin to query information about a
  * memory access.
diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
index 40c0d1abd2f..267ec381b4a 100644
--- a/plugins/qemu-plugins.symbols
+++ b/plugins/qemu-plugins.symbols
@@ -25,6 +25,7 @@
   qemu_plugin_insn_size;
   qemu_plugin_insn_vaddr;
   qemu_plugin_insn_haddr;
+  qemu_plugin_insn_disas;
   qemu_plugin_mem_size_shift;
   qemu_plugin_mem_is_sign_extended;
   qemu_plugin_mem_is_big_endian;
-- 
2.20.1



  parent reply index

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-25  6:36 [PULL v2 00/73] tcg plugins and testing updates Alex Bennée
2019-10-25  6:36 ` [PULL v2 01/73] travis.yml: reduce scope of the --enable-debug build Alex Bennée
2019-10-25  6:36 ` [PULL v2 02/73] travis.yml: Add libvdeplug-dev to compile-test net/vde.c Alex Bennée
2019-10-25  6:36 ` [PULL v2 03/73] travis.yml: Use libsdl2 instead of libsdl1.2, and install libsdl2-image Alex Bennée
2019-10-25  6:36 ` [PULL v2 04/73] travis.yml: Use newer version of libgnutls and libpng Alex Bennée
2019-10-25  6:36 ` [PULL v2 05/73] travis.yml: Fix the ccache lines Alex Bennée
2019-10-25  6:36 ` [PULL v2 06/73] travis.yml: Test the release tarball Alex Bennée
2019-10-25  6:36 ` [PULL v2 07/73] travis.yml: bump Xcode 10 to latest dot release Alex Bennée
2019-10-25  6:36 ` [PULL v2 08/73] cirrus.yml: add latest Xcode build target Alex Bennée
2019-10-25  6:36 ` [PULL v2 09/73] tests/vm: netbsd autoinstall, using serial console Alex Bennée
2019-10-25  6:36 ` [PULL v2 10/73] tests/vm: Let subclasses disable IPv6 Alex Bennée
2019-10-25  6:36 ` [PULL v2 11/73] tests/vm/netbsd: Disable IPv6 Alex Bennée
2019-10-25  6:36 ` [PULL v2 12/73] travis.yml: cache the clang sanitizer build Alex Bennée
2019-10-25  6:36 ` [PULL v2 13/73] gitlab-ci.yml: Use libvdeplug-dev to compile-test the VDE network backend Alex Bennée
2019-10-25  6:36 ` [PULL v2 14/73] travis.yml: --enable-debug-tcg to check-tcg Alex Bennée
2019-10-25  6:36 ` [PULL v2 15/73] tests/docker: set HOST_ARCH if we don't have ARCH Alex Bennée
2019-10-25  6:36 ` [PULL v2 16/73] tests/docker: update Travis image to a more current version Alex Bennée
2019-10-25  6:36 ` [PULL v2 17/73] trace: expand mem_info:size_shift to 4 bits Alex Bennée
2019-10-25  6:36 ` [PULL v2 18/73] trace: add mmu_index to mem_info Alex Bennée
2019-10-25  6:36 ` [PULL v2 19/73] cpu: introduce cpu_in_exclusive_context() Alex Bennée
2019-10-25  6:36 ` [PULL v2 20/73] translate-all: use cpu_in_exclusive_work_context() in tb_flush Alex Bennée
2019-10-25  6:36 ` [PULL v2 21/73] docs/devel: add plugins.rst design document Alex Bennée
2019-10-25  6:36 ` [PULL v2 22/73] plugin: add user-facing API Alex Bennée
2019-10-25  6:36 ` [PULL v2 23/73] plugin: add core code Alex Bennée
2019-10-25  6:36 ` [PULL v2 24/73] plugin: add implementation of the api Alex Bennée
2019-10-25  6:36 ` [PULL v2 25/73] queue: add QTAILQ_REMOVE_SEVERAL Alex Bennée
2019-10-25  6:36 ` [PULL v2 26/73] cputlb: document get_page_addr_code Alex Bennée
2019-10-25  6:36 ` [PULL v2 27/73] cputlb: introduce get_page_addr_code_hostp Alex Bennée
2019-10-25  6:36 ` [PULL v2 28/73] tcg: add tcg_gen_st_ptr Alex Bennée
2019-10-25  6:36 ` [PULL v2 29/73] plugin-gen: add module for TCG-related code Alex Bennée
2019-10-25  6:36 ` [PULL v2 30/73] atomic_template: add inline trace/plugin helpers Alex Bennée
2019-10-25  6:36 ` [PULL v2 31/73] tcg: let plugins instrument virtual memory accesses Alex Bennée
2019-10-25  6:36 ` [PULL v2 32/73] plugins: implement helpers for resolving hwaddr Alex Bennée
2019-10-25  6:36 ` [PULL v2 33/73] translate-all: notify plugin code of tb_flush Alex Bennée
2019-10-25  6:36 ` [PULL v2 34/73] *-user: notify plugin of exit Alex Bennée
2019-10-25  6:36 ` [PULL v2 35/73] *-user: plugin syscalls Alex Bennée
2019-10-25  6:36 ` [PULL v2 36/73] cpu: hook plugin vcpu events Alex Bennée
2019-10-25  6:36 ` [PULL v2 37/73] plugin-gen: add plugin_insn_append Alex Bennée
2019-10-25  6:36 ` [PULL v2 38/73] cputlb: ensure _cmmu helper functions follow the naming standard Alex Bennée
2019-10-25  6:36 ` [PULL v2 39/73] translator: add translator_ld{ub,sw,uw,l,q} Alex Bennée
2019-10-25  6:36 ` [PULL v2 40/73] target/arm: fetch code with translator_ld Alex Bennée
2019-10-25  6:36 ` [PULL v2 41/73] target/ppc: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 42/73] target/sh4: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 43/73] target/i386: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 44/73] target/hppa: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 45/73] target/m68k: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 46/73] target/alpha: " Alex Bennée
2019-10-25  7:40   ` USB-audio sound issues with qemu-system-ppc in Linux and Windows Howard Spoelstra
2019-10-25  6:36 ` [PULL v2 47/73] target/riscv: fetch code with translator_ld Alex Bennée
2019-10-25  6:36 ` [PULL v2 48/73] target/sparc: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 49/73] target/xtensa: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 50/73] target/openrisc: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 51/73] translator: inject instrumentation from plugins Alex Bennée
2019-10-25  6:36 ` [PULL v2 52/73] configure: add --enable-plugins Alex Bennée
2019-10-25  6:36 ` [PULL v2 53/73] plugin: add API symbols to qemu-plugins.symbols Alex Bennée
2019-10-25  6:36 ` [PULL v2 54/73] plugin: expand the plugin_init function to include an info block Alex Bennée
2019-10-25  6:36 ` Alex Bennée [this message]
2019-10-25  6:36 ` [PULL v2 56/73] plugin: add qemu_plugin_outs helper Alex Bennée
2019-10-25  6:36 ` [PULL v2 57/73] vl: support -plugin option Alex Bennée
2019-10-25  6:36 ` [PULL v2 58/73] linux-user: " Alex Bennée
2019-10-25  6:36 ` [PULL v2 59/73] tests/plugin: add sample plugins Alex Bennée
2019-10-25  6:37 ` [PULL v2 60/73] tests/tcg/Makefile.target: fix path to config-host.mak Alex Bennée
2019-10-25  6:37 ` [PULL v2 61/73] tests/tcg: set QEMU_OPTS for all cris runs Alex Bennée
2019-10-25  6:37 ` [PULL v2 62/73] tests/tcg: move "virtual" tests to EXTRA_TESTS Alex Bennée
2019-10-25  6:37 ` [PULL v2 63/73] tests/tcg: drop test-i386-fprem from TESTS when not SLOW Alex Bennée
2019-10-25  6:37 ` [PULL v2 64/73] tests/tcg: enable plugin testing Alex Bennée
2019-10-25  6:37 ` [PULL v2 65/73] tests/plugin: add a hotblocks plugin Alex Bennée
2019-10-25  6:37 ` [PULL v2 66/73] tests/plugin: add instruction execution breakdown Alex Bennée
2019-10-25  6:37 ` [PULL v2 67/73] tests/plugin: add hotpages to analyse memory access patterns Alex Bennée
2019-10-25  6:37 ` [PULL v2 68/73] accel/stubs: reduce headers from tcg-stub Alex Bennée
2019-10-25  6:37 ` [PULL v2 69/73] include/exec: wrap cpu_ldst.h in CONFIG_TCG Alex Bennée
2019-10-25  6:37 ` [PULL v2 70/73] .travis.yml: add --enable-plugins tests Alex Bennée
2019-10-25  6:37 ` [PULL v2 71/73] scripts/checkpatch.pl: don't complain about (foo, /* empty */) Alex Bennée
2019-10-25  6:37 ` [PULL v2 72/73] MAINTAINERS: add me for the TCG plugins code Alex Bennée
2019-10-25  6:37 ` [PULL v2 73/73] travis.yml: enable linux-gcc-debug-tcg cache Alex Bennée
2019-10-25 12:59 ` [PULL v2 00/73] tcg plugins and testing updates Markus Armbruster
2019-10-25 15:04   ` Alex Bennée
2019-10-25 20:23     ` Markus Armbruster
2019-10-27 19:44       ` Peter Maydell
2019-10-28  9:07         ` Alex Bennée
2019-11-06 12:42       ` Markus Armbruster
2019-11-08 17:23         ` Peter Maydell
2019-10-25 16:53 ` Peter Maydell
2019-10-25 19:38   ` Alex Bennée

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