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authormarcel <marcel@FreeBSD.org>2005-07-02 23:52:37 +0000
committermarcel <marcel@FreeBSD.org>2005-07-02 23:52:37 +0000
commit9e64e57e54a92f1dcb01125eafa15a65af897cdc (patch)
tree8c592ac5708941dd17f386936bfc56f9692ddb3e /sys/ia64
parentd7e928629d1fd82199b336e5a513e6308c7ec45b (diff)
downloadFreeBSD-src-9e64e57e54a92f1dcb01125eafa15a65af897cdc.zip
FreeBSD-src-9e64e57e54a92f1dcb01125eafa15a65af897cdc.tar.gz
Implement functions calls from within DDB on ia64. On ia64 a function
pointer doesn't point to the first instruction of that function, but rather to a descriptor. The descriptor has the address of the first instruction, as well as the value of the global pointer. The symbol table doesn't know anything about descriptors, so if you lookup the name of a function you get the address of the first instruction. The cast from the address, which is the result of the symbol lookup, to a function pointer as is done in db_fncall is therefore invalid. Abstract this detail behind the DB_CALL macro. By default DB_CALL is defined as db_fncall_generic, which yields the old behaviour. On ia64 the macro is defined as db_fncall_ia64, in which a descriptor is constructed to yield a valid function pointer. While here, introduce DB_MAXARGS. DB_MAXARGS replaces the existing (local) MAXARGS. The DB_MAXARGS macro can be defined by platforms to create a convenient maximum. By default this will be the legacy 10. On ia64 we define this macro to be 8, for 8 is the maximum number of arguments that can be passed in registers. This avoids having to implement spilling of arguments on the memory stack. Approved by: re (dwhite)
Diffstat (limited to 'sys/ia64')
-rw-r--r--sys/ia64/ia64/db_interface.c20
-rw-r--r--sys/ia64/include/db_machdep.h4
2 files changed, 24 insertions, 0 deletions
diff --git a/sys/ia64/ia64/db_interface.c b/sys/ia64/ia64/db_interface.c
index 53897b0..6d8a188 100644
--- a/sys/ia64/ia64/db_interface.c
+++ b/sys/ia64/ia64/db_interface.c
@@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$");
#include <machine/db_machdep.h>
#include <machine/frame.h>
+#include <machine/md_var.h>
#include <machine/mutex.h>
#include <machine/setjmp.h>
@@ -443,6 +444,25 @@ out:
return (loc + slot);
}
+typedef db_expr_t __db_f(db_expr_t, db_expr_t, db_expr_t, db_expr_t, db_expr_t,
+ db_expr_t, db_expr_t, db_expr_t);
+
+register uint64_t __db_gp __asm__("gp");
+
+int
+db_fncall_ia64(db_expr_t addr, db_expr_t *rv, int nargs, db_expr_t args[])
+{
+ struct ia64_fdesc fdesc;
+ __db_f *f;
+
+ f = (__db_f *)&fdesc;
+ fdesc.func = addr;
+ fdesc.gp = __db_gp; /* XXX doesn't work for modules. */
+ *rv = (*f)(args[0], args[1], args[2], args[3], args[4], args[5],
+ args[6], args[7]);
+ return (1);
+}
+
void
db_show_mdpcpu(struct pcpu *pc)
{
diff --git a/sys/ia64/include/db_machdep.h b/sys/ia64/include/db_machdep.h
index 5d5c7a5..cbf01a7 100644
--- a/sys/ia64/include/db_machdep.h
+++ b/sys/ia64/include/db_machdep.h
@@ -73,4 +73,8 @@ void db_bkpt_skip(void);
#define branch_taken(ins, pc, regs) pc
+/* Function call support. */
+#define DB_MAXARGS 8 /* Only support arguments in registers. */
+#define DB_CALL db_fncall_ia64
+
#endif /* _MACHINE_DB_MACHDEP_H_ */
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