Commit 9db18ed063 for qemu.org

commit 9db18ed0631d09f349057c22f7872b2c45275d0c
Author: Matt Turner <mattst88@gmail.com>
Date:   Mon May 25 17:53:08 2026 -0400

    linux-user/alpha: add coredump support

    Define HAVE_ELF_CORE_DUMP and target_elf_gregset_t in target_elf.h,
    mirroring the kernel's elf_gregset_t (ELF_NGREG = 66): r0-r31
    [0..31], f0-f31 [32..63], pc [64], unique [65].  Implement
    elf_core_copy_regs() in elfload.c to populate the gregset from
    CPUAlphaState.

    Without this, bprm->core_dump is NULL for Alpha targets.  When a
    guest signal goes unhandled, dump_core_and_abort() skips the core
    write and falls through to die_with_signal(), which re-raises the
    signal to the host.  The host kernel then writes an x86-64 core file
    for the qemu-alpha process instead of an Alpha guest core.

    v2: Store thread unique field, same as in Linux kernel. Added by Helge &
    suggested by Richard.

    Signed-off-by: Matt Turner <mattst88@gmail.com>
    Signed-off-by: Helge Deller <deller@gmx.de>
    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/linux-user/alpha/elfload.c b/linux-user/alpha/elfload.c
index 1e44475c47..1969f620a5 100644
--- a/linux-user/alpha/elfload.c
+++ b/linux-user/alpha/elfload.c
@@ -3,8 +3,20 @@
 #include "qemu/osdep.h"
 #include "qemu.h"
 #include "loader.h"
+#include "target_elf.h"


+void elf_core_copy_regs(target_elf_gregset_t *r, const CPUAlphaState *env)
+{
+    int i;
+
+    for (i = 0; i < 31; i++) {
+        r->regs[i] = tswap64(env->ir[i]);
+    }
+    r->pc = tswap64(env->pc);
+    r->unique = tswap64(env->unique);
+}
+
 const char *get_elf_cpu_model(uint32_t eflags)
 {
     return "ev67";
diff --git a/linux-user/alpha/target_elf.h b/linux-user/alpha/target_elf.h
index 864dc6e2e6..4987ae3944 100644
--- a/linux-user/alpha/target_elf.h
+++ b/linux-user/alpha/target_elf.h
@@ -11,4 +11,17 @@
 #define ELF_CLASS               ELFCLASS64
 #define ELF_MACHINE             EM_ALPHA

+#define HAVE_ELF_CORE_DUMP      1
+
+/*
+ * Matches the kernel's elf_gregset_t (ELF_NGREG = 33):
+ *   r0-r30 at indices 0-30, pc at 31, ps at 32.
+ * r31 (hardwired zero) is not stored; pc occupies index 31.
+ */
+typedef struct target_elf_gregset_t {
+    abi_ulong regs[31];  /* integer registers r0-r30  [0..30] */
+    abi_ulong pc;        /* program counter           [31]    */
+    abi_ulong unique;    /* thread's UNIQUE field     [32]    */
+} target_elf_gregset_t;
+
 #endif