From: Andrew Burgess <andrew.burgess@embecosm.com>
To: binutils@sourceware.org, gdb-patches@sourceware.org
Subject: [PATCH 4/8] bfd/riscv: prepare to handle bare metal core dump creation
Date: Wed, 2 Dec 2020 17:39:28 +0000 [thread overview]
Message-ID: <1738a5518a1dc57b34e4a8b13fa9b5e46f2a8d88.1606930261.git.andrew.burgess@embecosm.com> (raw)
In-Reply-To: <cover.1606930261.git.andrew.burgess@embecosm.com>
When creating a core file GDB will call the function
elfcore_write_prstatus to write out the general purpose registers
along with the pid/tid for the thread.
However, for a bare metal RISC-V tool chain the prstatus*_t types are
not defined so the elfcore_write_prstatus function will return NULL,
preventing core file creation.
This commit provides the `elf_backend_write_core_note' hook and uses
the provided function to write out the ptstatus information.
In order to keep changes in the non bare metal tools to a minimum, the
provided backend function will itself return NULL when the prstatus*_t
types are available, the consequence of this is that the generic code
in elfcore_write_prstatus will be used just as before. But, when
prstatus*_t is not available, the new backend function will write out
the prstatus information using predefined offsets.
This new functionality will be used by a later GDB commit that will
add bare metal core dumps for RISC-V.
bfd/ChangeLog:
* elfnn-riscv.c (riscv_write_core_note): New function.
(elf_backend_write_core_note): Define.
---
bfd/ChangeLog | 6 ++++
bfd/elfnn-riscv.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 79 insertions(+)
diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 20944c8109f..cffdf0b21f2 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -4874,6 +4874,77 @@ _bfd_riscv_relax_section (bfd *abfd, asection *sec,
# define PRPSINFO_OFFSET_PR_PSARGS 56
#endif
+/* Write PRSTATUS note into core file. This will be called before the
+ generic code in elf.c. By checking the compiler defines we only perform
+ any action here if the generic code would otherwise not be able to help
+ us. The intention is that bare metal core dumps (where the prstatus32_t
+ might not be available) will use this code, while non bare metal tools
+ will use the generic elf code. */
+
+static char *
+riscv_write_core_note (bfd *abfd ATTRIBUTE_UNUSED,
+ char *buf ATTRIBUTE_UNUSED,
+ int *bufsiz ATTRIBUTE_UNUSED,
+ int note_type ATTRIBUTE_UNUSED, ...)
+{
+ switch (note_type)
+ {
+ default:
+ return NULL;
+
+#if !defined (HAVE_PRPSINFO_T)
+ case NT_PRPSINFO:
+ {
+ char data[PRPSINFO_SIZE] ATTRIBUTE_NONSTRING;
+ va_list ap;
+
+ va_start (ap, note_type);
+ memset (data, 0, sizeof (data));
+ strncpy (data + PRPSINFO_OFFSET_PR_FNAME, va_arg (ap, const char *), 16);
+#if GCC_VERSION == 8000 || GCC_VERSION == 8001
+ DIAGNOSTIC_PUSH;
+ /* GCC 8.0 and 8.1 warn about 80 equals destination size with
+ -Wstringop-truncation:
+ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643
+ */
+ DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION;
+#endif
+ strncpy (data + PRPSINFO_OFFSET_PR_PSARGS, va_arg (ap, const char *), 80);
+#if GCC_VERSION == 8000 || GCC_VERSION == 8001
+ DIAGNOSTIC_POP;
+#endif
+ va_end (ap);
+ return elfcore_write_note (abfd, buf, bufsiz,
+ "CORE", note_type, data, sizeof (data));
+ }
+#endif /* !HAVE_PRPSINFO_T */
+
+#if !defined (HAVE_PRSTATUS_T)
+ case NT_PRSTATUS:
+ {
+ char data[PRSTATUS_SIZE];
+ va_list ap;
+ long pid;
+ int cursig;
+ const void *greg;
+
+ va_start (ap, note_type);
+ memset (data, 0, sizeof(data));
+ pid = va_arg (ap, long);
+ bfd_put_32 (abfd, pid, data + PRSTATUS_OFFSET_PR_PID);
+ cursig = va_arg (ap, int);
+ bfd_put_16 (abfd, cursig, data + PRSTATUS_OFFSET_PR_CURSIG);
+ greg = va_arg (ap, const void *);
+ memcpy (data + PRSTATUS_OFFSET_PR_REG, greg,
+ PRSTATUS_SIZE - PRSTATUS_OFFSET_PR_REG - ARCH_SIZE / 8);
+ va_end (ap);
+ return elfcore_write_note (abfd, buf, bufsiz,
+ "CORE", note_type, data, sizeof (data));
+ }
+#endif /* !HAVE_PRSTATUS_T */
+ }
+}
+
/* Support for core dump NOTE sections. */
static bfd_boolean
@@ -4984,6 +5055,8 @@ riscv_elf_obj_attrs_arg_type (int tag)
#define elf_backend_grok_prstatus riscv_elf_grok_prstatus
#define elf_backend_grok_psinfo riscv_elf_grok_psinfo
#define elf_backend_object_p riscv_elf_object_p
+#undef elf_backend_write_core_note
+#define elf_backend_write_core_note riscv_write_core_note
#define elf_info_to_howto_rel NULL
#define elf_info_to_howto riscv_info_to_howto_rela
#define bfd_elfNN_bfd_relax_section _bfd_riscv_relax_section
--
2.25.4
next prev parent reply other threads:[~2020-12-02 17:39 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 17:39 [PATCH 0/8] Bare-metal core dumps for RISC-V Andrew Burgess
2020-12-02 17:39 ` [PATCH 1/8] gdb/riscv: use a single regset supply function for riscv fbsd & linux Andrew Burgess
2021-01-18 14:15 ` Andrew Burgess
2020-12-02 17:39 ` [PATCH 2/8] bfd/binutils: support for gdb target descriptions in the core file Andrew Burgess
2020-12-02 18:21 ` Luis Machado
2020-12-02 22:58 ` Jim Wilson
2020-12-03 12:16 ` Luis Machado
[not found] ` <20201214115512.GI2945@embecosm.com>
2021-01-11 10:19 ` Andrew Burgess
2021-01-11 13:03 ` Luis Machado
2020-12-07 12:48 ` Andrew Burgess
2020-12-02 17:39 ` [PATCH 3/8] gdb: write target description into " Andrew Burgess
2020-12-03 20:36 ` Tom Tromey
2020-12-07 14:38 ` Andrew Burgess
2020-12-02 17:39 ` Andrew Burgess [this message]
2020-12-02 23:24 ` [PATCH 4/8] bfd/riscv: prepare to handle bare metal core dump creation Jim Wilson
2020-12-07 14:39 ` Andrew Burgess
2020-12-02 17:39 ` [PATCH 5/8] gdb/riscv: introduce bare metal core dump support Andrew Burgess
2020-12-02 18:12 ` Luis Machado
2020-12-07 15:17 ` Andrew Burgess
2020-12-07 15:58 ` Luis Machado
2020-12-07 16:58 ` Andrew Burgess
2020-12-07 17:24 ` Luis Machado
2020-12-07 18:11 ` Andrew Burgess
2020-12-07 19:00 ` Luis Machado
2020-12-07 19:23 ` Andrew Burgess
2020-12-07 19:39 ` Luis Machado
2020-12-07 19:51 ` Paul Mathieu
2020-12-13 10:13 ` Fredrik Hederstierna
2020-12-02 17:39 ` [PATCH 6/8] bfd/binutils: add support for RISC-V CSRs in core files Andrew Burgess
2020-12-02 23:50 ` Jim Wilson
2020-12-07 15:19 ` Andrew Burgess
2020-12-14 13:37 ` Andrew Burgess
2020-12-02 17:39 ` [PATCH 7/8] gdb/riscv: make riscv target description names global Andrew Burgess
2020-12-02 17:39 ` [PATCH 8/8] gdb/riscv: write CSRs into baremetal core dumps Andrew Burgess
2020-12-02 23:59 ` [PATCH 0/8] Bare-metal core dumps for RISC-V Jim Wilson
2020-12-07 12:10 ` Andrew Burgess
2020-12-07 19:57 ` Jim Wilson
2020-12-03 20:40 ` Tom Tromey
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