[PATCH 4/4] gdbstub: Remove @g_pos argument in gdb_register_coprocessor()

Philippe Mathieu-Daudé posted 4 patches 2 days, 11 hours ago
Maintainers: "Alex Bennée" <alex.bennee@linaro.org>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, John Snow <jsnow@redhat.com>, Cleber Rosa <crosa@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Brian Cain <brian.cain@oss.qualcomm.com>, Paolo Bonzini <pbonzini@redhat.com>, Zhao Liu <zhao1.liu@intel.com>, Song Gao <gaosong@loongson.cn>, Laurent Vivier <laurent@vivier.eu>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Nicholas Piggin <npiggin@gmail.com>, Chinmay Rath <rathc@linux.ibm.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Weiwei Li <liwei1518@gmail.com>, Daniel Henrique Barboza <dbarboza@ventanamicro.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>, Thomas Huth <thuth@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Ilya Leoshkevich <iii@linux.ibm.com>, David Hildenbrand <david@kernel.org>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Artyom Tarasenko <atar4qemu@gmail.com>
[PATCH 4/4] gdbstub: Remove @g_pos argument in gdb_register_coprocessor()
Posted by Philippe Mathieu-Daudé 2 days, 11 hours ago
gdb_register_coprocessor()'s @g_pos argument is always '0',
meaning it is inferred from cpu->gdb_num_regs. Use instead
feature->base_reg, but check we don't overwrite other indexed
registers.

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/e44df309-d40d-46f0-88a8-7ac55f9a3634@fhofhammer.de/

Reported-by: Florian Hofhammer <florian.hofhammer@fhofhammer.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/exec/gdbstub.h     |  3 +--
 gdbstub/gdbstub.c          | 16 +++++-----------
 target/arm/gdbstub.c       | 21 ++++++++-------------
 target/arm/gdbstub64.c     | 19 +++++++------------
 target/hexagon/cpu.c       |  2 +-
 target/i386/gdbstub.c      |  8 +++-----
 target/loongarch/gdbstub.c |  6 +++---
 target/m68k/helper.c       |  4 ++--
 target/microblaze/cpu.c    |  3 +--
 target/ppc/gdbstub.c       | 11 +++++------
 target/riscv/gdbstub.c     | 18 ++++++------------
 target/s390x/gdbstub.c     | 15 +++++++--------
 target/sparc/gdbstub.c     | 12 ++++--------
 13 files changed, 53 insertions(+), 85 deletions(-)

diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index 12e7b5b7282..75eb4d9c365 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -35,11 +35,10 @@ void gdb_init_cpu(CPUState *cpu);
  * @set_reg - set function (gdb modifying)
  * @num_regs - number of registers in set
  * @xml - xml name of set
- * @gpos - non-zero to append to "general" register set at @gpos
  */
 void gdb_register_coprocessor(CPUState *cpu,
                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
-                              const GDBFeature *feature, int g_pos);
+                              const GDBFeature *feature);
 
 /**
  * gdb_unregister_coprocessor_all() - unregisters supplemental set of registers
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 6eadae3804e..882bc67e182 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -604,13 +604,14 @@ void gdb_init_cpu(CPUState *cpu)
 
 void gdb_register_coprocessor(CPUState *cpu,
                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
-                              const GDBFeature *feature, int g_pos)
+                              const GDBFeature *feature)
 {
     GDBRegisterState *s;
     guint i;
-    int base_reg = cpu->gdb_num_regs;
+    int base_reg;
 
-    assert(!g_pos || g_pos == feature->base_reg);
+    assert(feature->base_reg >= cpu->gdb_num_regs);
+    base_reg = feature->base_reg;
 
     for (i = 0; i < cpu->gdb_regs->len; i++) {
         /* Check for duplicates.  */
@@ -624,14 +625,7 @@ void gdb_register_coprocessor(CPUState *cpu,
 
     /* Add to end of list.  */
     cpu->gdb_num_regs += feature->num_regs;
-    if (g_pos) {
-        if (g_pos != base_reg) {
-            error_report("Error: Bad gdb register numbering for '%s', "
-                         "expected %d got %d", feature->xml, g_pos, base_reg);
-        } else {
-            cpu->gdb_num_g_regs = cpu->gdb_num_regs;
-        }
-    }
+    cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 }
 
 void gdb_unregister_coprocessor_all(CPUState *cpu)
diff --git a/target/arm/gdbstub.c b/target/arm/gdbstub.c
index c7d59fd3726..d6e29c4cf46 100644
--- a/target/arm/gdbstub.c
+++ b/target/arm/gdbstub.c
@@ -534,15 +534,13 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
     } else {
         if (arm_feature(env, ARM_FEATURE_NEON)) {
             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
-                                     gdb_find_static_feature("arm-neon.xml"),
-                                     0);
+                                     gdb_find_static_feature("arm-neon.xml"));
         } else if (cpu_isar_feature(aa32_simd_r32, cpu)) {
             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
-                                     gdb_find_static_feature("arm-vfp3.xml"),
-                                     0);
+                                     gdb_find_static_feature("arm-vfp3.xml"));
         } else if (cpu_isar_feature(aa32_vfp_simd, cpu)) {
             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
-                                     gdb_find_static_feature("arm-vfp.xml"), 0);
+                                     gdb_find_static_feature("arm-vfp.xml"));
         }
         if (!arm_feature(env, ARM_FEATURE_M)) {
             /*
@@ -550,29 +548,26 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
              * expose to gdb.
              */
             gdb_register_coprocessor(cs, vfp_gdb_get_sysreg, vfp_gdb_set_sysreg,
-                                     gdb_find_static_feature("arm-vfp-sysregs.xml"),
-                                     0);
+                                     gdb_find_static_feature("arm-vfp-sysregs.xml"));
         }
     }
     if (cpu_isar_feature(aa32_mve, cpu) && tcg_enabled()) {
         gdb_register_coprocessor(cs, mve_gdb_get_reg, mve_gdb_set_reg,
-                                 gdb_find_static_feature("arm-m-profile-mve.xml"),
-                                 0);
+                                 gdb_find_static_feature("arm-m-profile-mve.xml"));
     }
     gdb_register_coprocessor(cs, arm_gdb_get_sysreg, arm_gdb_set_sysreg,
-                             arm_gen_dynamic_sysreg_feature(cs, cs->gdb_num_regs),
-                             0);
+                             arm_gen_dynamic_sysreg_feature(cs, cs->gdb_num_regs));
 
 #ifdef CONFIG_TCG
     if (arm_feature(env, ARM_FEATURE_M) && tcg_enabled()) {
         gdb_register_coprocessor(cs,
             arm_gdb_get_m_systemreg, arm_gdb_set_m_systemreg,
-            arm_gen_dynamic_m_systemreg_feature(cs, cs->gdb_num_regs), 0);
+            arm_gen_dynamic_m_systemreg_feature(cs, cs->gdb_num_regs));
 #ifndef CONFIG_USER_ONLY
         if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
             gdb_register_coprocessor(cs,
                 arm_gdb_get_m_secextreg, arm_gdb_set_m_secextreg,
-                arm_gen_dynamic_m_secextreg_feature(cs, cs->gdb_num_regs), 0);
+                arm_gen_dynamic_m_secextreg_feature(cs, cs->gdb_num_regs));
         }
 #endif
     }
diff --git a/target/arm/gdbstub64.c b/target/arm/gdbstub64.c
index b71666c3a1d..a4fa740caf6 100644
--- a/target/arm/gdbstub64.c
+++ b/target/arm/gdbstub64.c
@@ -887,24 +887,22 @@ void aarch64_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
         isar_feature_aa64_sme(&cpu->isar)) {
         GDBFeature *feature = arm_gen_dynamic_svereg_feature(cs, cs->gdb_num_regs);
         gdb_register_coprocessor(cs, aarch64_gdb_get_sve_reg,
-                                 aarch64_gdb_set_sve_reg, feature, 0);
+                                 aarch64_gdb_set_sve_reg, feature);
     } else {
         gdb_register_coprocessor(cs, aarch64_gdb_get_fpu_reg,
                                  aarch64_gdb_set_fpu_reg,
-                                 gdb_find_static_feature("aarch64-fpu.xml"),
-                                 0);
+                                 gdb_find_static_feature("aarch64-fpu.xml"));
     }
 
     if (isar_feature_aa64_sme(&cpu->isar)) {
         GDBFeature *sme_feature =
             arm_gen_dynamic_smereg_feature(cs, cs->gdb_num_regs);
         gdb_register_coprocessor(cs, aarch64_gdb_get_sme_reg,
-                                 aarch64_gdb_set_sme_reg, sme_feature, 0);
+                                 aarch64_gdb_set_sme_reg, sme_feature);
         if (isar_feature_aa64_sme2(&cpu->isar)) {
             gdb_register_coprocessor(cs, aarch64_gdb_get_sme2_reg,
                                      aarch64_gdb_set_sme2_reg,
-                                     gdb_find_static_feature("aarch64-sme2.xml"),
-                                     0);
+                                     gdb_find_static_feature("aarch64-sme2.xml"));
         }
     }
     /*
@@ -916,8 +914,7 @@ void aarch64_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
     if (isar_feature_aa64_pauth(&cpu->isar)) {
         gdb_register_coprocessor(cs, aarch64_gdb_get_pauth_reg,
                                  aarch64_gdb_set_pauth_reg,
-                                 gdb_find_static_feature("aarch64-pauth.xml"),
-                                 0);
+                                 gdb_find_static_feature("aarch64-pauth.xml"));
     }
 
 #ifdef CONFIG_USER_ONLY
@@ -925,14 +922,12 @@ void aarch64_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
     if (cpu_isar_feature(aa64_mte, cpu)) {
         gdb_register_coprocessor(cs, aarch64_gdb_get_tag_ctl_reg,
                                  aarch64_gdb_set_tag_ctl_reg,
-                                 gdb_find_static_feature("aarch64-mte.xml"),
-                                 0);
+                                 gdb_find_static_feature("aarch64-mte.xml"));
     }
 #endif
 
     /* All AArch64 CPUs have at least TPIDR */
     gdb_register_coprocessor(cs, aarch64_gdb_get_tls_reg,
                              aarch64_gdb_set_tls_reg,
-                             arm_gen_dynamic_tls_feature(cs, cs->gdb_num_regs),
-                             0);
+                             arm_gen_dynamic_tls_feature(cs, cs->gdb_num_regs));
 }
diff --git a/target/hexagon/cpu.c b/target/hexagon/cpu.c
index 58a22ee41f2..ffd14bb4678 100644
--- a/target/hexagon/cpu.c
+++ b/target/hexagon/cpu.c
@@ -322,7 +322,7 @@ static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
 
     gdb_register_coprocessor(cs, hexagon_hvx_gdb_read_register,
                              hexagon_hvx_gdb_write_register,
-                             gdb_find_static_feature("hexagon-hvx.xml"), 0);
+                             gdb_find_static_feature("hexagon-hvx.xml"));
 
     qemu_init_vcpu(cs);
     cpu_reset(cs);
diff --git a/target/i386/gdbstub.c b/target/i386/gdbstub.c
index f1ce90a046e..4e87b67cc13 100644
--- a/target/i386/gdbstub.c
+++ b/target/i386/gdbstub.c
@@ -503,8 +503,7 @@ void x86_cpu_gdb_init(CPUState *cs)
     if (env->features[FEAT_7_1_EDX] & CPUID_7_1_EDX_APXF) {
         gdb_register_coprocessor(cs, i386_cpu_gdb_get_egprs,
                                  i386_cpu_gdb_set_egprs,
-                                 gdb_find_static_feature("i386-64bit-apx.xml"),
-                                 0);
+                                 gdb_find_static_feature("i386-64bit-apx.xml"));
     }
 #endif
 
@@ -512,10 +511,9 @@ void x86_cpu_gdb_init(CPUState *cs)
     gdb_register_coprocessor(cs, x86_cpu_gdb_read_linux_register,
                              x86_cpu_gdb_write_linux_register,
 #ifdef TARGET_X86_64
-                             gdb_find_static_feature("i386-64bit-linux.xml"),
+                             gdb_find_static_feature("i386-64bit-linux.xml"));
 #else
-                             gdb_find_static_feature("i386-32bit-linux.xml"),
+                             gdb_find_static_feature("i386-32bit-linux.xml"));
 #endif
-                             0);
 #endif
 }
diff --git a/target/loongarch/gdbstub.c b/target/loongarch/gdbstub.c
index 23a5eecc20b..3e9bdfa8bbf 100644
--- a/target/loongarch/gdbstub.c
+++ b/target/loongarch/gdbstub.c
@@ -180,16 +180,16 @@ void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
 
     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, FP)) {
         gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
-                                 gdb_find_static_feature("loongarch-fpu.xml"), 0);
+                                 gdb_find_static_feature("loongarch-fpu.xml"));
     }
 
     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, LSX)) {
         gdb_register_coprocessor(cs, loongarch_gdb_get_lsx, loongarch_gdb_set_lsx,
-                                 gdb_find_static_feature("loongarch-lsx.xml"), 0);
+                                 gdb_find_static_feature("loongarch-lsx.xml"));
     }
 
     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, LASX)) {
         gdb_register_coprocessor(cs, loongarch_gdb_get_lasx, loongarch_gdb_set_lasx,
-                                 gdb_find_static_feature("loongarch-lasx.xml"), 0);
+                                 gdb_find_static_feature("loongarch-lasx.xml"));
     }
 }
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index c566cb0a16c..9bab1843892 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -129,10 +129,10 @@ void m68k_cpu_init_gdb(M68kCPU *cpu)
 
     if (m68k_feature(env, M68K_FEATURE_CF_FPU)) {
         gdb_register_coprocessor(cs, cf_fpu_gdb_get_reg, cf_fpu_gdb_set_reg,
-                                 gdb_find_static_feature("cf-fp.xml"), 0);
+                                 gdb_find_static_feature("cf-fp.xml"));
     } else if (m68k_feature(env, M68K_FEATURE_FPU)) {
         gdb_register_coprocessor(cs, m68k_fpu_gdb_get_reg, m68k_fpu_gdb_set_reg,
-                                 gdb_find_static_feature("m68k-fp.xml"), 0);
+                                 gdb_find_static_feature("m68k-fp.xml"));
     }
     /* TODO: Add [E]MAC registers.  */
 }
diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
index ae41a1a3287..ec513ae82d4 100644
--- a/target/microblaze/cpu.c
+++ b/target/microblaze/cpu.c
@@ -265,8 +265,7 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
 
     gdb_register_coprocessor(cs, mb_cpu_gdb_read_stack_protect,
                              mb_cpu_gdb_write_stack_protect,
-                             gdb_find_static_feature("microblaze-stack-protect.xml"),
-                             0);
+                             gdb_find_static_feature("microblaze-stack-protect.xml"));
 
     qemu_init_vcpu(cs);
 
diff --git a/target/ppc/gdbstub.c b/target/ppc/gdbstub.c
index e0aae9c9eaf..4d622c5cad5 100644
--- a/target/ppc/gdbstub.c
+++ b/target/ppc/gdbstub.c
@@ -502,24 +502,23 @@ void ppc_gdb_init(CPUState *cs, PowerPCCPUClass *pcc)
 {
     if (pcc->insns_flags & PPC_FLOAT) {
         gdb_register_coprocessor(cs, gdb_get_float_reg, gdb_set_float_reg,
-                                 gdb_find_static_feature("power-fpu.xml"), 0);
+                                 gdb_find_static_feature("power-fpu.xml"));
     }
     if (pcc->insns_flags & PPC_ALTIVEC) {
         gdb_register_coprocessor(cs, gdb_get_avr_reg, gdb_set_avr_reg,
-                                 gdb_find_static_feature("power-altivec.xml"),
-                                 0);
+                                 gdb_find_static_feature("power-altivec.xml"));
     }
     if (pcc->insns_flags & PPC_SPE) {
         gdb_register_coprocessor(cs, gdb_get_spe_reg, gdb_set_spe_reg,
-                                 gdb_find_static_feature("power-spe.xml"), 0);
+                                 gdb_find_static_feature("power-spe.xml"));
     }
     if (pcc->insns_flags2 & PPC2_VSX) {
         gdb_register_coprocessor(cs, gdb_get_vsx_reg, gdb_set_vsx_reg,
-                                 gdb_find_static_feature("power-vsx.xml"), 0);
+                                 gdb_find_static_feature("power-vsx.xml"));
     }
 #ifndef CONFIG_USER_ONLY
     gdb_gen_spr_feature(cs);
     gdb_register_coprocessor(cs, gdb_get_spr_reg, gdb_set_spr_reg,
-                             &pcc->gdb_spr, 0);
+                             &pcc->gdb_spr);
 #endif
 }
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index a053009ccd3..6a5b7a82fd4 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -348,32 +348,27 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
     CPURISCVState *env = &cpu->env;
     if (env->misa_ext & RVD) {
         gdb_register_coprocessor(cs, riscv_gdb_get_fpu, riscv_gdb_set_fpu,
-                                 gdb_find_static_feature("riscv-64bit-fpu.xml"),
-                                 0);
+                                 gdb_find_static_feature("riscv-64bit-fpu.xml"));
     } else if (env->misa_ext & RVF) {
         gdb_register_coprocessor(cs, riscv_gdb_get_fpu, riscv_gdb_set_fpu,
-                                 gdb_find_static_feature("riscv-32bit-fpu.xml"),
-                                 0);
+                                 gdb_find_static_feature("riscv-32bit-fpu.xml"));
     }
     if (cpu->cfg.ext_zve32x) {
         gdb_register_coprocessor(cs, riscv_gdb_get_vector,
                                  riscv_gdb_set_vector,
-                                 ricsv_gen_dynamic_vector_feature(cs, cs->gdb_num_regs),
-                                 0);
+                                 ricsv_gen_dynamic_vector_feature(cs, cs->gdb_num_regs));
     }
     switch (mcc->def->misa_mxl_max) {
     case MXL_RV32:
         gdb_register_coprocessor(cs, riscv_gdb_get_virtual,
                                  riscv_gdb_set_virtual,
-                                 gdb_find_static_feature("riscv-32bit-virtual.xml"),
-                                 0);
+                                 gdb_find_static_feature("riscv-32bit-virtual.xml"));
         break;
     case MXL_RV64:
     case MXL_RV128:
         gdb_register_coprocessor(cs, riscv_gdb_get_virtual,
                                  riscv_gdb_set_virtual,
-                                 gdb_find_static_feature("riscv-64bit-virtual.xml"),
-                                 0);
+                                 gdb_find_static_feature("riscv-64bit-virtual.xml"));
         break;
     default:
         g_assert_not_reached();
@@ -381,7 +376,6 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
 
     if (cpu->cfg.ext_zicsr) {
         gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr,
-                                 riscv_gen_dynamic_csr_feature(cs, cs->gdb_num_regs),
-                                 0);
+                                 riscv_gen_dynamic_csr_feature(cs, cs->gdb_num_regs));
     }
 }
diff --git a/target/s390x/gdbstub.c b/target/s390x/gdbstub.c
index 9ae715add4d..efdaaefa6d0 100644
--- a/target/s390x/gdbstub.c
+++ b/target/s390x/gdbstub.c
@@ -347,34 +347,33 @@ void s390_cpu_gdb_init(CPUState *cs)
 {
     gdb_register_coprocessor(cs, cpu_read_ac_reg,
                              cpu_write_ac_reg,
-                             gdb_find_static_feature("s390-acr.xml"), 0);
+                             gdb_find_static_feature("s390-acr.xml"));
 
     gdb_register_coprocessor(cs, cpu_read_fp_reg,
                              cpu_write_fp_reg,
-                             gdb_find_static_feature("s390-fpr.xml"), 0);
+                             gdb_find_static_feature("s390-fpr.xml"));
 
     gdb_register_coprocessor(cs, cpu_read_vreg,
                              cpu_write_vreg,
-                             gdb_find_static_feature("s390-vx.xml"), 0);
+                             gdb_find_static_feature("s390-vx.xml"));
 
     gdb_register_coprocessor(cs, cpu_read_gs_reg,
                              cpu_write_gs_reg,
-                             gdb_find_static_feature("s390-gs.xml"), 0);
+                             gdb_find_static_feature("s390-gs.xml"));
 
 #ifndef CONFIG_USER_ONLY
     gdb_register_coprocessor(cs, cpu_read_c_reg,
                              cpu_write_c_reg,
-                             gdb_find_static_feature("s390-cr.xml"), 0);
+                             gdb_find_static_feature("s390-cr.xml"));
 
     gdb_register_coprocessor(cs, cpu_read_virt_reg,
                              cpu_write_virt_reg,
-                             gdb_find_static_feature("s390-virt.xml"), 0);
+                             gdb_find_static_feature("s390-virt.xml"));
 
     if (kvm_enabled()) {
         gdb_register_coprocessor(cs, cpu_read_virt_kvm_reg,
                                  cpu_write_virt_kvm_reg,
-                                 gdb_find_static_feature("s390-virt-kvm.xml"),
-                                 0);
+                                 gdb_find_static_feature("s390-virt-kvm.xml"));
     }
 #endif
 }
diff --git a/target/sparc/gdbstub.c b/target/sparc/gdbstub.c
index 792bf70a145..2874ce1b350 100644
--- a/target/sparc/gdbstub.c
+++ b/target/sparc/gdbstub.c
@@ -271,20 +271,16 @@ void sparc_cpu_register_gdb_regs(CPUState *cs)
 #if defined(TARGET_ABI32) || !defined(TARGET_SPARC64)
     gdb_register_coprocessor(cs, sparc_fpu_gdb_read_register,
                              sparc_fpu_gdb_write_register,
-                             gdb_find_static_feature("sparc32-fpu.xml"),
-                             0);
+                             gdb_find_static_feature("sparc32-fpu.xml"));
     gdb_register_coprocessor(cs, sparc_cp0_gdb_read_register,
                              sparc_cp0_gdb_write_register,
-                             gdb_find_static_feature("sparc32-cp0.xml"),
-                             0);
+                             gdb_find_static_feature("sparc32-cp0.xml"));
 #else
     gdb_register_coprocessor(cs, sparc_fpu_gdb_read_register,
                              sparc_fpu_gdb_write_register,
-                             gdb_find_static_feature("sparc64-fpu.xml"),
-                             0);
+                             gdb_find_static_feature("sparc64-fpu.xml"));
     gdb_register_coprocessor(cs, sparc_cp0_gdb_read_register,
                              sparc_cp0_gdb_write_register,
-                             gdb_find_static_feature("sparc64-cp0.xml"),
-                             0);
+                             gdb_find_static_feature("sparc64-cp0.xml"));
 #endif
 }
-- 
2.52.0


Re: [PATCH 4/4] gdbstub: Remove @g_pos argument in gdb_register_coprocessor()
Posted by Pierrick Bouvier 2 days, 11 hours ago
On 2/27/26 1:39 PM, Philippe Mathieu-Daudé wrote:
> gdb_register_coprocessor()'s @g_pos argument is always '0',
> meaning it is inferred from cpu->gdb_num_regs. Use instead
> feature->base_reg, but check we don't overwrite other indexed
> registers.
> 
> 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/e44df309-d40d-46f0-88a8-7ac55f9a3634@fhofhammer.de/
> 
> Reported-by: Florian Hofhammer <florian.hofhammer@fhofhammer.de>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   include/exec/gdbstub.h     |  3 +--
>   gdbstub/gdbstub.c          | 16 +++++-----------
>   target/arm/gdbstub.c       | 21 ++++++++-------------
>   target/arm/gdbstub64.c     | 19 +++++++------------
>   target/hexagon/cpu.c       |  2 +-
>   target/i386/gdbstub.c      |  8 +++-----
>   target/loongarch/gdbstub.c |  6 +++---
>   target/m68k/helper.c       |  4 ++--
>   target/microblaze/cpu.c    |  3 +--
>   target/ppc/gdbstub.c       | 11 +++++------
>   target/riscv/gdbstub.c     | 18 ++++++------------
>   target/s390x/gdbstub.c     | 15 +++++++--------
>   target/sparc/gdbstub.c     | 12 ++++--------
>   13 files changed, 53 insertions(+), 85 deletions(-)
> 

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>