From 8c080d3a974ad471d8324825851044284f1886c9 Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Tue, 23 Jun 2020 13:36:42 +0800 Subject: [PATCH] kgdb: enable arch to support XML packet. The XML packet could be supported by required architecture if the architecture defines CONFIG_HAVE_ARCH_KGDB_QXFER_PKT and implement its own kgdb_arch_handle_qxfer_pkt(). Except for the kgdb_arch_handle_qxfer_pkt(), the architecture also needs to record the feature supported by gdb stub into the kgdb_arch_gdb_stub_feature, and these features will be reported to host gdb when gdb stub receives the qSupported packet. Signed-off-by: Vincent Chen Acked-by: Daniel Thompson Signed-off-by: Palmer Dabbelt --- include/linux/kgdb.h | 11 +++++++++++ kernel/debug/gdbstub.c | 13 +++++++++++++ lib/Kconfig.kgdb | 5 +++++ 3 files changed, 29 insertions(+) diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 529116b0cabe..0e4e3a80d58c 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -176,6 +176,17 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code, char *remcom_out_buffer, struct pt_regs *regs); +/** + * kgdb_arch_handle_qxfer_pkt - Handle architecture specific GDB XML + * packets. + * @remcom_in_buffer: The buffer of the packet we have read. + * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. + */ + +extern void +kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer, + char *remcom_out_buffer); + /** * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU * @ignored: This parameter is only here to match the prototype. diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index 61774aec46b4..a790026e42d0 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -792,6 +792,19 @@ static void gdb_cmd_query(struct kgdb_state *ks) } break; #endif +#ifdef CONFIG_HAVE_ARCH_KGDB_QXFER_PKT + case 'S': + if (!strncmp(remcom_in_buffer, "qSupported:", 11)) + strcpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature); + break; + case 'X': + if (!strncmp(remcom_in_buffer, "qXfer:", 6)) + kgdb_arch_handle_qxfer_pkt(remcom_in_buffer, + remcom_out_buffer); + break; +#endif + default: + break; } } diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb index ffa7a76de086..256f2486f9bd 100644 --- a/lib/Kconfig.kgdb +++ b/lib/Kconfig.kgdb @@ -3,6 +3,11 @@ config HAVE_ARCH_KGDB bool +# set if architecture has the its kgdb_arch_handle_qxfer_pkt +# function to enable gdb stub to address XML packet sent from GDB. +config HAVE_ARCH_KGDB_QXFER_PKT + bool + menuconfig KGDB bool "KGDB: kernel debugger" depends on HAVE_ARCH_KGDB