Add rodata support

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>

libdtrace/Build

@@ -61,6 +61,7 @@ libdtrace-build_SOURCES = dt_aggregate.c \
 			  dt_provider_sdt.c \
 			  dt_provider_tp.c \
 			  dt_regset.c \
+			  dt_rodata.c \
 			  dt_string.c \
 			  dt_strtab.c \
 			  dt_subr.c \

libdtrace/dt_bpf.c

@@ -711,7 +711,9 @@ gmap_create_strtab(dtrace_hdl_t *dtp)
 	int		fd, rc, err;
 
 	dtp->dt_strlen = dt_strtab_size(dtp->dt_ccstab);
-	dtp->dt_zerooffset = P2ROUNDUP(dtp->dt_strlen, 8);
+	dtp->dt_rooffset = P2ROUNDUP(dtp->dt_strlen, 8);
+	dtp->dt_rosize = dt_rodata_size(dtp->dt_rodata);
+	dtp->dt_zerooffset = P2ROUNDUP(dtp->dt_rooffset + dtp->dt_rosize, 8);
 
 	/*
 	 * Ensure the zero-filled memory at the end of the strtab is large
@@ -730,6 +732,7 @@ gmap_create_strtab(dtrace_hdl_t *dtp)
 	if (strtab == NULL)
 		return dt_set_errno(dtp, EDT_NOMEM);
 
+	/* Copy the string table data. */
 	dt_strtab_write(dtp->dt_ccstab, (dt_strtab_write_f *)dt_strtab_copystr,
 			strtab);
 
@@ -745,6 +748,10 @@ gmap_create_strtab(dtrace_hdl_t *dtp)
 		buf += len + 1;
 	}
 
+	/* Copy the read-only data. */
+	dt_rodata_write(dtp->dt_rodata, (dt_rodata_copy_f *)dt_rodata_copy,
+			strtab + dtp->dt_rooffset);
+
 	fd = create_gmap(dtp, "strtab", BPF_MAP_TYPE_ARRAY, sizeof(uint32_t),
 			 sz, 1);
 	if (fd == -1)

libdtrace/dt_bpf.h

@@ -19,25 +19,27 @@ struct dtrace_hdl;
 extern "C" {
 #endif
 
-#define DT_CONST_EPID	1
-#define DT_CONST_PRID	2
-#define DT_CONST_CLID	3
-#define DT_CONST_ARGC	4
-#define DT_CONST_STBSZ	5
-#define DT_CONST_STRSZ	6
-#define DT_CONST_STKSIZ	7
-#define DT_CONST_BOOTTM	8
-#define DT_CONST_NSPEC	9
-#define DT_CONST_NCPUS	10
-#define DT_CONST_PC	11
-#define DT_CONST_TUPSZ	12
-#define DT_CONST_TASK_PID	13
-#define DT_CONST_TASK_TGID	14
+#define DT_CONST_EPID			1
+#define DT_CONST_PRID			2
+#define DT_CONST_CLID			3
+#define DT_CONST_ARGC			4
+#define DT_CONST_STBSZ			5
+#define DT_CONST_STRSZ			6
+#define DT_CONST_STKSIZ			7
+#define DT_CONST_BOOTTM			8
+#define DT_CONST_NSPEC			9
+#define DT_CONST_NCPUS			10
+#define DT_CONST_PC			11
+#define DT_CONST_TUPSZ			12
+#define DT_CONST_TASK_PID		13
+#define DT_CONST_TASK_TGID		14
 #define DT_CONST_TASK_REAL_PARENT	15
-#define DT_CONST_TASK_COMM	16
-#define DT_CONST_MUTEX_OWNER	17
-#define DT_CONST_RWLOCK_CNTS	18
-#define DT_CONST_ZERO_OFF	19
+#define DT_CONST_TASK_COMM		16
+#define DT_CONST_MUTEX_OWNER		17
+#define DT_CONST_RWLOCK_CNTS		18
+#define DT_CONST_RODATA_OFF		19
+#define DT_CONST_RODATA_SIZE		20
+#define DT_CONST_ZERO_OFF		21
 
 #define DT_BPF_LOG_SIZE_DEFAULT	(UINT32_MAX >> 8)
 #define DT_BPF_LOG_SIZE_SMALL	4096

libdtrace/dt_cc.c

@@ -2468,6 +2468,12 @@ dt_link_construct(dtrace_hdl_t *dtp, const dt_probe_t *prp, dtrace_difo_t *dp,
 				nrp->dofr_data = total_offset;
 				continue;
 			}
+			case DT_CONST_RODATA_OFF:
+				nrp->dofr_data = dtp->dt_rooffset;
+				continue;
+			case DT_CONST_RODATA_SIZE:
+				nrp->dofr_data = dtp->dt_rosize;
+				continue;
 			case DT_CONST_ZERO_OFF:
 				nrp->dofr_data = dtp->dt_zerooffset;
 				continue;

libdtrace/dt_cg.c

@@ -56,6 +56,7 @@ dt_cg_tramp_prologue_act(dt_pcb_t *pcb, dt_activity_t act)
 	dt_ident_t	*mem = dt_dlib_get_map(dtp, "mem");
 	dt_ident_t	*state = dt_dlib_get_map(dtp, "state");
 	dt_ident_t	*prid = dt_dlib_get_var(pcb->pcb_hdl, "PRID");
+	dt_ident_t	*ro_off = dt_dlib_get_var(dtp, "RODATA_OFF");
 	uint_t		lbl_exit = pcb->pcb_exitlbl;
 
 	assert(aggs != NULL);
@@ -206,6 +207,16 @@ dt_cg_tramp_prologue_act(dt_pcb_t *pcb, dt_activity_t act)
 	} while(0)
 
 	DT_CG_STORE_MAP_PTR("strtab", DCTX_STRTAB);
+
+	/*
+	 * We know that a pointer to the strtab data is in %r0 (because that is
+	 * where the DT_CG_STORE_MAP_PTR() macro left it, and we know that dctx
+	 * is in %r9.  So, we can just add RODATA_OFF to %r0, and store that in
+	 * [%r9 + DCTX_RODATA].
+	 */
+	emite(dlp, BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, -1), ro_off);
+	emit(dlp,  BPF_STORE(BPF_DW, BPF_REG_9, DCTX_RODATA, BPF_REG_0));
+
 	if (dtp->dt_options[DTRACEOPT_SCRATCHSIZE] > 0)
 		DT_CG_STORE_MAP_PTR("scratchmem", DCTX_SCRATCHMEM);
 	if (dt_idhash_datasize(dtp->dt_globals) > 0)

libdtrace/dt_dctx.h

@@ -58,6 +58,7 @@ typedef struct dt_dctx {
 	char		*mem;		/* General scratch memory */
 	char		*scratchmem;	/* Scratch space for alloca, etc */
 	char		*strtab;	/* String constant table */
+	char		*rodata;	/* Read-only data */
 	char		*agg;		/* Aggregation data */
 	char		*gvars;		/* Global variables */
 	char		*lvars;		/* Local variables */
@@ -70,6 +71,7 @@ typedef struct dt_dctx {
 #define DCTX_MEM	offsetof(dt_dctx_t, mem)
 #define DCTX_SCRATCHMEM	offsetof(dt_dctx_t, scratchmem)
 #define DCTX_STRTAB	offsetof(dt_dctx_t, strtab)
+#define DCTX_RODATA	offsetof(dt_dctx_t, rodata)
 #define DCTX_AGG	offsetof(dt_dctx_t, agg)
 #define DCTX_GVARS	offsetof(dt_dctx_t, gvars)
 #define DCTX_LVARS	offsetof(dt_dctx_t, lvars)

libdtrace/dt_dlibs.c

@@ -91,6 +91,8 @@ static const dt_ident_t		dt_bpf_symbols[] = {
 	DT_BPF_SYMBOL_ID(TASK_COMM, DT_IDENT_SCALAR, DT_CONST_TASK_COMM),
 	DT_BPF_SYMBOL_ID(MUTEX_OWNER, DT_IDENT_SCALAR, DT_CONST_MUTEX_OWNER),
 	DT_BPF_SYMBOL_ID(RWLOCK_CNTS, DT_IDENT_SCALAR, DT_CONST_RWLOCK_CNTS),
+	DT_BPF_SYMBOL_ID(RODATA_OFF, DT_IDENT_SCALAR, DT_CONST_RODATA_OFF),
+	DT_BPF_SYMBOL_ID(RODATA_SIZE, DT_IDENT_SCALAR, DT_CONST_RODATA_SIZE),
 	DT_BPF_SYMBOL_ID(ZERO_OFF, DT_IDENT_SCALAR, DT_CONST_ZERO_OFF),
 
 	/* End-of-list marker */

libdtrace/dt_impl.h

@@ -34,6 +34,7 @@ extern "C" {
 #include <dt_bpf_maps.h>
 #include <dt_parser.h>
 #include <dt_regset.h>
+#include <dt_rodata.h>
 #include <dt_strtab.h>
 #include <dt_symtab.h>
 #include <dt_ident.h>
@@ -306,14 +307,17 @@ struct dtrace_hdl {
 	dt_idhash_t *dt_tls;	/* hash table of thread-local identifiers */
 	dt_idhash_t *dt_bpfsyms;/* hash table of BPF identifiers */
 	dt_strtab_t *dt_ccstab;	/* global string table (during compilation) */
+	dt_rodata_t *dt_rodata;	/* global read-only data */
 	uint_t dt_strlen;	/* global string table (runtime) size */
+	uint_t dt_rooffset;	/* read-only data offset */
+	uint_t dt_rosize;	/* read-only data size */
+	uint_t dt_zerooffset;	/* zero region, offset */
+	uint_t dt_zerosize;	/* zero region, size */
 	uint_t dt_maxreclen;	/* largest record size across programs */
 	uint_t dt_maxdvarsize;	/* largest dynamic variable across programs */
 	uint_t dt_maxtuplesize;	/* largest tuple across programs */
 	uint_t dt_maxlvaralloc;	/* largest lvar alloc across pcbs */
 	uint_t dt_maxaggdsize;	/* largest aggregation data sizw */
-	uint_t dt_zerosize;	/* zero region, size */
-	uint_t dt_zerooffset;	/* zero region, offset */
 	dt_tstring_t *dt_tstrings; /* temporary string slots */
 	dt_list_t dt_modlist;	/* linked list of dt_module_t's */
 	dt_htab_t *dt_mods;	/* hash table of dt_module_t's */
@@ -725,6 +729,8 @@ extern int dt_version_defined(dt_version_t);
 
 extern int dt_str2kver(const char *, dt_version_t *);
 
+extern uint32_t dt_gen_hval(const char *, uint32_t, size_t);
+
 /*
  * Miscellaneous internal libdtrace interfaces.  The definitions below are for
  * libdtrace routines that do not yet merit their own separate header file.

libdtrace/dt_open.c

@@ -888,6 +888,7 @@ dt_vopen(int version, int flags, int *errp,
 	    DIF_VAR_OTHER_UBASE, DIF_VAR_OTHER_MAX);
 
 	dtp->dt_ccstab = dt_strtab_create(BUFSIZ);
+	dtp->dt_rodata = dt_rodata_create(BUFSIZ);
 	dtp->dt_strlen = 0;
 
 	if (dtp->dt_macros == NULL || dtp->dt_aggs == NULL ||