From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52819) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xu2Nm-0005hM-Id for qemu-devel@nongnu.org; Thu, 27 Nov 2014 11:57:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xu2Nd-0008UM-Hl for qemu-devel@nongnu.org; Thu, 27 Nov 2014 11:57:30 -0500 Received: from mail-wg0-x22a.google.com ([2a00:1450:400c:c00::22a]:46564) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xu2Nd-0008UC-Bk for qemu-devel@nongnu.org; Thu, 27 Nov 2014 11:57:21 -0500 Received: by mail-wg0-f42.google.com with SMTP id z12so6987339wgg.15 for ; Thu, 27 Nov 2014 08:57:20 -0800 (PST) Sender: Paolo Bonzini Message-ID: <547757ED.2080206@redhat.com> Date: Thu, 27 Nov 2014 17:57:17 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <5471E103.6080109@gmail.com> In-Reply-To: <5471E103.6080109@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] gdbstub: Support AUXV packet for debugging PIE executables. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Wei-cheng, Wang" , riku.voipio@linaro.org, qemu-devel CCing Riku Voipio for a review. Paolo On 23/11/2014 14:28, Wei-cheng, Wang wrote: > Hi, > > This patch adds support for sending AUXV packet. > This is required for debugging Linux position independent executables. > Otherwise, gdb client cannot find out where the executable is loaded. > > Signed-off-by: Wei-cheng, Wang > --- > gdbstub.c | 41 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > > diff --git a/gdbstub.c b/gdbstub.c > index d1b5afd..30f3bbc 100644 > --- a/gdbstub.c > +++ b/gdbstub.c > @@ -1127,6 +1127,7 @@ static int gdb_handle_packet(GDBState *s, const > char *line_buf) > if (cc->gdb_core_xml_file != NULL) { > pstrcat(buf, sizeof(buf), ";qXfer:features:read+"); > } > + pstrcat(buf, sizeof(buf), ";qXfer:auxv:read+"); > put_packet(s, buf); > break; > } > @@ -1173,6 +1174,46 @@ static int gdb_handle_packet(GDBState *s, const > char *line_buf) > put_packet_binary(s, buf, len + 1); > break; > } > +#ifdef CONFIG_USER_ONLY > + if (strncmp(p, "Xfer:auxv:read:", 15) == 0) { > + TaskState *ts = s->c_cpu->opaque; > + target_ulong auxv = ts->info->saved_auxv; > + target_ulong auxv_len = ts->info->auxv_len; > + char *ptr; > + > + p += 15; > + while (*p && *p != ':') > + p++; > + p++; > + > + addr = strtoul(p, (char **)&p, 16); > + if (*p == ',') > + p++; > + len = strtoul(p, (char **)&p, 16); > + > + ptr = lock_user(VERIFY_READ, auxv, auxv_len, 0); > + if (ptr == NULL) { > + break; > + } > + > + if (addr > len) { > + snprintf(buf, sizeof(buf), "E00"); > + put_packet(s, buf); > + break; > + } > + if (len > (MAX_PACKET_LENGTH - 5) / 2) > + len = (MAX_PACKET_LENGTH - 5) / 2; > + if (len < auxv_len - addr) { > + buf[0] = 'm'; > + len = memtox(buf + 1, ptr + addr, len); > + } else { > + buf[0] = 'l'; > + len = memtox(buf + 1, ptr + addr, auxv_len - addr); > + } > + put_packet_binary(s, buf, len + 1); > + unlock_user(ptr, auxv, len); > + } > +#endif /* !CONFIG_USER_ONLY */ > /* Unrecognised 'q' command. */ > goto unknown_command; >