When a feature XML file provides a "regnum=" tag to indicate
the registers base index, respect it, as it might not be the
same as our current number of registered entries, in particular
when there are gaps.
This fixes a bug with the "power-fpu.xml" file [*] which was
loaded at index 70 while the base register is 71. This latent
bug was exposed by commit 1ec0fbe2dda ("target/ppc: Fix
CPUClass::gdb_num_core_regs value").
[*]
https://lore.kernel.org/qemu-devel/[email protected]/
Reported-by: Florian Hofhammer <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
---
gdbstub/gdbstub.c | 6 ++++++
gdbstub/trace-events | 1 +
2 files changed, 7 insertions(+)
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 69038c66f2b..c3c944e965b 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -601,6 +601,7 @@ void gdb_init_cpu(CPUState *cpu)
if (xmlfile) {
assert(!cc->gdb_num_core_regs);
feature = gdb_find_static_feature(xmlfile);
+ assert(feature->base_reg == 0);
gdb_register_feature(cpu, 0,
cc->gdb_read_register, cc->gdb_write_register,
feature);
@@ -630,6 +631,11 @@ void gdb_register_coprocessor(CPUState *cpu,
}
}
+ if (base_reg < feature->base_reg) {
+ trace_gdbxml_register_coprocessor_gap(base_reg,
+ feature->base_reg);
+ base_reg = feature->base_reg;
+ }
gdb_register_feature(cpu, base_reg, get_reg, set_reg, feature);
/* Add to end of list. */
diff --git a/gdbstub/trace-events b/gdbstub/trace-events
index 8caee36c242..5bc83946743 100644
--- a/gdbstub/trace-events
+++ b/gdbstub/trace-events
@@ -29,6 +29,7 @@ gdbstub_err_checksum_incorrect(uint8_t expected, uint8_t got)
"got command packe
gdbstub_err_unexpected_runpkt(uint8_t ch) "unexpected packet (0x%02x) while
target running"
gdbxml_init_cpu(const char *typename, unsigned id, unsigned gdb_num_regs,
unsigned gdb_num_g_regs, unsigned gdb_num_core_regs) "%s:%d regs:%u g_regs:%u
core_regs:%u"
+gdbxml_register_coprocessor_gap(unsigned gdb_num_regs, unsigned base_reg)
"regs %u -> %u"
gdbxml_register_feature(const char *featname, const char *xmlname, unsigned
base_reg, unsigned num_regs) "%s (%s) @%u +%u"
gdbxml_feature_builder_header(const char *name, const char *xmlname, int
num_regs) "%s (%s) regs:%d"
gdbxml_feature_builder_content(const char *xml) "%s"
--
2.53.0
