From: Luis Machado <luis.machado@linaro.org>
To: gdb-patches@sourceware.org
Subject: [PATCH v6 17/25] AArch64: Report tag violation error information
Date: Mon, 22 Mar 2021 10:21:11 -0300 [thread overview]
Message-ID: <20210322132120.1202230-18-luis.machado@linaro.org> (raw)
In-Reply-To: <20210322132120.1202230-1-luis.machado@linaro.org>
Updates on v6:
- Output logical tag when reporting a tag fault.
Updates on v4:
- Print exception error.
- Update function names.
--
Whenever a memory tag violation occurs, we get a SIGSEGV. Additional
information can be obtained through the siginfo data structure.
For AArch64 the Linux kernel may expose the fault address and tag
information, if we have a synchronous event. Otherwise there is
no fault address available.
The synchronous event looks like this:
--
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault
Memory tag violation while accessing address 0x0500fffff7ff8000
Allocation tag 0x1.
Logical tag 0x5
--
The asynchronous event looks like this:
--
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault
Memory tag violation
Fault address unavailable.
--
gdb/ChangeLog:
YYYY-MM-DD Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c
(aarch64_linux_report_signal_info): New function.
(aarch64_linux_init_abi): Register
aarch64_linux_report_signal_info as the report_signal_info hook.
* arch/aarch64-linux.h (SEGV_MTEAERR): Define.
(SEGV_MTESERR): Define.
---
gdb/aarch64-linux-tdep.c | 70 ++++++++++++++++++++++++++++++++++++
gdb/arch/aarch64-mte-linux.h | 6 ++++
2 files changed, 76 insertions(+)
diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
index 9434f90e8f6..55f49e555a1 100644
--- a/gdb/aarch64-linux-tdep.c
+++ b/gdb/aarch64-linux-tdep.c
@@ -1687,6 +1687,73 @@ aarch64_linux_memtag_to_string (struct gdbarch *gdbarch, struct value *tag_value
return string_printf ("0x%s", phex_nz (tag, sizeof (tag)));
}
+/* AArch64 Linux implementation of the report_signal_info gdbarch
+ hook. Displays information about possible memory tag violations. */
+
+static void
+aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
+ struct ui_out *uiout,
+ enum gdb_signal siggnal)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (!tdep->has_mte () || siggnal != GDB_SIGNAL_SEGV)
+ return;
+
+ CORE_ADDR fault_addr = 0;
+ long si_code = 0;
+
+ try
+ {
+ /* Sigcode tells us if the segfault is actually a memory tag
+ violation. */
+ si_code = parse_and_eval_long ("$_siginfo.si_code");
+
+ fault_addr
+ = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
+ }
+ catch (const gdb_exception_error &exception)
+ {
+ exception_print (gdb_stderr, exception);
+ return;
+ }
+
+ /* If this is not a memory tag violation, just return. */
+ if (si_code != SEGV_MTEAERR && si_code != SEGV_MTESERR)
+ return;
+
+ uiout->text ("\n");
+
+ uiout->field_string ("sigcode-meaning", _("Memory tag violation"));
+
+ /* For synchronous faults, show additional information. */
+ if (si_code == SEGV_MTESERR)
+ {
+ uiout->text (_(" while accessing address "));
+ uiout->field_core_addr ("fault-addr", gdbarch, fault_addr);
+ uiout->text ("\n");
+
+ gdb::optional<CORE_ADDR> atag = aarch64_mte_get_atag (fault_addr);
+ gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
+
+ if (!atag.has_value ())
+ uiout->text (_("Allocation tag unavailable"));
+ else
+ {
+ uiout->text (_("Allocation tag "));
+ uiout->field_string ("allocation-tag", hex_string (*atag));
+ uiout->text ("\n");
+ uiout->text (_("Logical tag "));
+ uiout->field_string ("logical-tag", hex_string (ltag));
+ }
+ }
+ else
+ {
+ uiout->text ("\n");
+ uiout->text (_("Fault address unavailable"));
+ }
+}
+
static void
aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
@@ -1767,6 +1834,9 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
/* Register a hook for converting a memory tag to a string. */
set_gdbarch_memtag_to_string (gdbarch, aarch64_linux_memtag_to_string);
+
+ set_gdbarch_report_signal_info (gdbarch,
+ aarch64_linux_report_signal_info);
}
/* Initialize the aarch64_linux_record_tdep. */
diff --git a/gdb/arch/aarch64-mte-linux.h b/gdb/arch/aarch64-mte-linux.h
index f517638831c..2aa97eb861a 100644
--- a/gdb/arch/aarch64-mte-linux.h
+++ b/gdb/arch/aarch64-mte-linux.h
@@ -35,6 +35,12 @@
#define AARCH64_MTE_LOGICAL_TAG_START_BIT 56
#define AARCH64_MTE_LOGICAL_MAX_VALUE 0xf
+/* Memory tagging definitions. */
+#ifndef SEGV_MTEAERR
+# define SEGV_MTEAERR 8
+# define SEGV_MTESERR 9
+#endif
+
/* Memory tag types for AArch64. */
enum class aarch64_memtag_type
{
--
2.25.1
next prev parent reply other threads:[~2021-03-22 13:21 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 13:20 [PATCH v6 00/25] Memory Tagging Support + AArch64 Linux implementation Luis Machado
2021-03-22 13:20 ` [PATCH v6 01/25] New target methods for memory tagging support Luis Machado
2021-03-23 21:22 ` Simon Marchi
2021-03-22 13:20 ` [PATCH v6 02/25] New gdbarch memory tagging hooks Luis Machado
2021-03-22 13:20 ` [PATCH v6 03/25] Add GDB-side remote target support for memory tagging Luis Machado
2021-03-22 13:20 ` [PATCH v6 04/25] Unit testing for GDB-side remote memory tagging handling Luis Machado
2021-03-22 13:20 ` [PATCH v6 05/25] GDBserver remote packet support for memory tagging Luis Machado
2021-03-22 13:21 ` [PATCH v6 06/25] Unit tests for gdbserver memory tagging remote packets Luis Machado
2021-03-22 13:21 ` [PATCH v6 07/25] Documentation for " Luis Machado
2021-03-22 17:47 ` Eli Zaretskii
2021-03-22 13:21 ` [PATCH v6 08/25] AArch64: Add MTE CPU feature check support Luis Machado
2021-03-22 13:21 ` [PATCH v6 09/25] AArch64: Add target description/feature for MTE registers Luis Machado
2021-03-22 13:21 ` [PATCH v6 10/25] AArch64: Add MTE register set support for GDB and gdbserver Luis Machado
2021-03-22 13:21 ` [PATCH v6 11/25] AArch64: Add MTE ptrace requests Luis Machado
2021-03-22 13:21 ` [PATCH v6 12/25] AArch64: Implement memory tagging target methods for AArch64 Luis Machado
2021-03-22 13:21 ` [PATCH v6 13/25] Convert char array to std::string in linux_find_memory_regions_full Luis Machado
2021-03-22 13:21 ` [PATCH v6 14/25] Refactor parsing of /proc/<pid>/smaps Luis Machado
2021-03-23 21:28 ` Simon Marchi
2021-03-22 13:21 ` [PATCH v6 15/25] AArch64: Implement the memory tagging gdbarch hooks Luis Machado
2021-03-23 21:32 ` Simon Marchi
2021-03-22 13:21 ` [PATCH v6 16/25] AArch64: Add unit testing for logical tag set/get operations Luis Machado
2022-01-31 14:34 ` Simon Marchi
2021-03-22 13:21 ` Luis Machado [this message]
2021-03-22 13:21 ` [PATCH v6 18/25] AArch64: Add gdbserver MTE support Luis Machado
2021-03-22 13:21 ` [PATCH v6 19/25] AArch64: Add MTE register set support for core files Luis Machado
2021-03-22 13:21 ` [PATCH v6 20/25] New memory-tag commands Luis Machado
2021-03-22 13:21 ` [PATCH v6 21/25] Documentation for the new mtag commands Luis Machado
2021-03-22 17:49 ` Eli Zaretskii
2021-03-22 13:21 ` [PATCH v6 22/25] Extend "x" and "print" commands to support memory tagging Luis Machado
2021-03-22 13:21 ` [PATCH v6 23/25] Document new "x" and "print" memory tagging extensions Luis Machado
2021-03-22 17:51 ` Eli Zaretskii
2021-03-22 13:21 ` [PATCH v6 24/25] Add NEWS entry Luis Machado
2021-03-22 17:51 ` Eli Zaretskii
2021-03-22 17:52 ` Luis Machado
2021-03-22 13:21 ` [PATCH v6 25/25] Add memory tagging testcases Luis Machado
2021-03-23 22:50 ` [PATCH v6 00/25] Memory Tagging Support + AArch64 Linux implementation Simon Marchi
2021-03-24 18:18 ` Luis Machado
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