Merge pull request #816 from fjtrujy/srxfixup_zero_text_dectection

fjtrujy · web-flow · commit 20d0fe9a84d1 · 2026-03-06T23:21:06.000+01:00
srxfixup: detect and fix function symbols at .text offset 0
diff --git a/common/sbus/Makefile b/common/sbus/Makefile
@@ -29,7 +29,7 @@ IOP_INCS += \
 
 IOP_OBJS_DIR = iop_obj/
 
-IOP_OBJS = ps2_sbus.o iop_sbus.o ps2_sif.o iop_sif2.o sif2cmd.o imports.o exports.o
+IOP_OBJS = exports.o iop_sbus.o iop_sif2.o ps2_sbus.o ps2_sif.o sif2cmd.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/ee/Rules.lib.make
diff --git a/iop/Rules.make b/iop/Rules.make
@@ -145,8 +145,15 @@ $(IOP_BIN_STRIPPED_ELF): $(IOP_BIN_ELF)
 	$(DIR_GUARD)
 	$(IOP_STRIP) --strip-unneeded --remove-section=.pdr --remove-section=.comment --remove-section=.mdebug.abi32 --remove-section=.gnu.attributes -o $@ $<
 
+# If the module has no export table, allow symbols at .text offset 0.
+# The jal 0x0 hazard only matters when an export table can dispatch to offset 0.
+IOP_SRXFIXUP_FLAGS := --rb --irx1
+ifeq ($(filter %exports.o,$(IOP_OBJS)),)
+IOP_SRXFIXUP_FLAGS += --allow-zero-text
+endif
+
 $(IOP_BIN): $(IOP_BIN_STRIPPED_ELF) $(PS2SDKSRC)/tools/srxfixup/bin/srxfixup
-	$(PS2SDKSRC)/tools/srxfixup/bin/srxfixup --rb --irx1 -o $@ $<
+	$(PS2SDKSRC)/tools/srxfixup/bin/srxfixup $(IOP_SRXFIXUP_FLAGS) -o $@ $<
 
 $(IOP_LIB)_tmp$(MAKE_CURPID): $(IOP_OBJS)
 	$(DIR_GUARD)
diff --git a/iop/arcade/acatad/Makefile b/iop/arcade/acatad/Makefile
@@ -16,9 +16,9 @@ IOP_IMPORT_INCS += \
 	system/threadman
 
 IOP_OBJS = \
+	exports.o \
 	acatad.o \
-	imports.o \
-	exports.o
+	imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/arcade/accdvd/Makefile b/iop/arcade/accdvd/Makefile
@@ -19,14 +19,14 @@ IOP_IMPORT_INCS += \
 	system/threadman
 
 IOP_OBJS = \
+	exports.o \
 	accdvdi-entry.o \
 	acd.o \
 	cdc.o \
 	cdi.o \
 	cddrv.o \
 	cdfs.o \
-	imports.o \
-	exports.o
+	imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/arcade/acdev/Makefile b/iop/arcade/acdev/Makefile
@@ -14,9 +14,9 @@ IOP_IMPORT_INCS += \
 	system/sysmem
 
 IOP_OBJS = \
+	exports.o \
 	acdev.o \
-	imports.o \
-	exports.o
+	imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/arcade/acdev9/Makefile b/iop/arcade/acdev9/Makefile
@@ -12,9 +12,9 @@ IOP_IMPORT_INCS += \
 	system/stdio
 
 IOP_OBJS = \
+	exports.o \
 	acdev9.o \
-	imports.o \
-	exports.o
+	imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/cdvd/cdvdfsv/Makefile b/iop/cdvd/cdvdfsv/Makefile
@@ -21,7 +21,7 @@ IOP_IMPORT_INCS += \
 	system/sysmem \
 	system/threadman
 
-IOP_OBJS = cdvdfsv.o imports.o exports.o
+IOP_OBJS = exports.o cdvdfsv.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/cdvd/cdvdman/Makefile b/iop/cdvd/cdvdman/Makefile
@@ -18,7 +18,7 @@ IOP_IMPORT_INCS += \
 	system/sysmem \
 	system/threadman
 
-IOP_OBJS = cdvdman.o imports.o exports.o
+IOP_OBJS = exports.o cdvdman.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/cdvd/cdvdstm/Makefile b/iop/cdvd/cdvdstm/Makefile
@@ -19,7 +19,7 @@ IOP_IMPORT_INCS += \
 	system/sysmem \
 	system/threadman
 
-IOP_OBJS = cdvdstm.o imports.o exports.o
+IOP_OBJS = exports.o cdvdstm.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/debug/ioptrap/Makefile b/iop/debug/ioptrap/Makefile
@@ -17,7 +17,7 @@ IOP_IMPORT_INCS += \
 	system/sysclib \
 	system/threadman
 
-IOP_OBJS = ioptrap.o handler.o breakpoint.o exports.o imports.o
+IOP_OBJS = exports.o ioptrap.o handler.o breakpoint.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/debug/sior/Makefile b/iop/debug/sior/Makefile
@@ -13,7 +13,7 @@ IOP_IMPORT_INCS += \
 	system/sysclib \
 	system/threadman
 
-IOP_OBJS = sior.o xprintf.o exports.o imports.o
+IOP_OBJS = exports.o sior.o xprintf.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/dev9/pvrdrv/Makefile b/iop/dev9/pvrdrv/Makefile
@@ -16,7 +16,7 @@ IOP_IMPORT_INCS += \
 	system/sysmem \
 	system/threadman
 
-IOP_OBJS = dvrdrv.o exports.o imports.o
+IOP_OBJS = exports.o dvrdrv.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/fs/devfs/Makefile b/iop/fs/devfs/Makefile
@@ -17,7 +17,7 @@ IOP_IMPORT_INCS += \
 	system/sysmem \
 	system/threadman
 
-IOP_OBJS = devfs.o exports.o imports.o
+IOP_OBJS = exports.o devfs.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/fs/romdrv/src/exports.tab b/iop/fs/romdrv/src/exports.tab
@@ -1,5 +1,3 @@
-void _retonly(void) {}
-
 DECLARE_EXPORT_TABLE(romdrv, 2, 1)
 	DECLARE_EXPORT(_start)
 	DECLARE_EXPORT(_retonly)
@@ -21,3 +19,5 @@ DECLARE_EXPORT_TABLE(romdrvX, 1, 1)
 	DECLARE_EXPORT(romGetDevice)
 END_EXPORT_TABLE
 #endif
+
+void _retonly(void) {}
diff --git a/iop/memorycard/mcman/Makefile b/iop/memorycard/mcman/Makefile
@@ -36,14 +36,14 @@ IOP_IMPORT_INCS += \
     system/timrman
 
 IOP_OBJS = \
+    exports.o \
     main.o \
     mcdev.o \
     mciomanx_backing.o \
     mcsio2.o \
     ps2mc_fio.o \
     ps1mc_fio.o \
-    imports.o \
-    exports.o
+    imports.o
 
 ifneq (x$(MCMAN_BUILDING_XMCMAN),x0)
 IOP_CFLAGS += -DBUILDING_XMCMAN
diff --git a/iop/memorycard/mcserv/Makefile b/iop/memorycard/mcserv/Makefile
@@ -22,7 +22,7 @@ IOP_IMPORT_INCS += \
 	system/sysclib \
 	system/threadman
 
-IOP_OBJS = mcserv.o imports.o exports.o
+IOP_OBJS = exports.o mcserv.o imports.o
 
 ifneq (x$(MCMAN_BUILDING_XMCSERV),x0)
 IOP_CFLAGS += -DBUILDING_XMCSERV
diff --git a/iop/network/netman/src/exports.tab b/iop/network/netman/src/exports.tab
@@ -1,5 +1,3 @@
-void _retonly(){};
-
 DECLARE_EXPORT_TABLE(netman, 3, 1)
 	DECLARE_EXPORT(_start)
 	DECLARE_EXPORT(_retonly)
@@ -23,3 +21,5 @@ DECLARE_EXPORT_TABLE(netman, 3, 1)
 	DECLARE_EXPORT(NetManTxPacketNext)
 	DECLARE_EXPORT(NetManTxPacketDeQ)
 END_EXPORT_TABLE
+
+void _retonly(){};
diff --git a/iop/network/smap-none/Makefile b/iop/network/smap-none/Makefile
@@ -14,4 +14,7 @@ IOP_INC_DIR = $(PS2SDKSRC)/iop/network/smap/include/
 SMAP_NETMAN ?= 0
 SMAP_PS2IP ?= 0
 
+# No export table for this variant, exclude exports.o
+IOP_OBJS = main.o smap.o xfer.o ipstack.o imports.o
+
 include $(PS2SDKSRC)/iop/network/smap/Makefile
diff --git a/iop/network/smap-ps2ip/Makefile b/iop/network/smap-ps2ip/Makefile
@@ -14,4 +14,7 @@ IOP_INC_DIR = $(PS2SDKSRC)/iop/network/smap/include/
 SMAP_NETMAN ?= 0
 SMAP_PS2IP ?= 1
 
+# No export table for this variant, exclude exports.o
+IOP_OBJS = main.o smap.o xfer.o ipstack.o imports.o
+
 include $(PS2SDKSRC)/iop/network/smap/Makefile
diff --git a/iop/network/smap/Makefile b/iop/network/smap/Makefile
@@ -35,7 +35,7 @@ IOP_IMPORT_INCS += \
 	system/sysclib \
 	system/threadman
 
-IOP_OBJS = ipstack.o main.o smap.o xfer.o imports.o exports.o
+IOP_OBJS ?= exports.o main.o smap.o xfer.o ipstack.o imports.o
 
 ifneq (x$(LWIP_DHCP),x0)
 IOP_CFLAGS += -DLWIP_DHCP=1
diff --git a/iop/network/smap/src/exports.tab b/iop/network/smap/src/exports.tab
@@ -1,6 +1,3 @@
-
-void _retonly(){};
-
 #ifdef BUILDING_SMAP_NETMAN
 DECLARE_EXPORT_TABLE(smap, 1, 1)
 	DECLARE_EXPORT(_retonly)
@@ -19,3 +16,5 @@ DECLARE_EXPORT_TABLE(smapmodu, 1, 1)
 	DECLARE_EXPORT(SmapModularGetExportTable)
 END_EXPORT_TABLE
 #endif
+
+void _retonly(){};
diff --git a/iop/network/udptty/src/exports.tab b/iop/network/udptty/src/exports.tab
@@ -1,9 +1,9 @@
-void _retonly(void) {}
-
 DECLARE_EXPORT_TABLE(udptty, 1, 1)
 	DECLARE_EXPORT(_start)
 	DECLARE_EXPORT(_retonly)
 	DECLARE_EXPORT(_shutdown)
 	DECLARE_EXPORT(_retonly)
 	DECLARE_EXPORT(_retonly)
 END_EXPORT_TABLE
+
+void _retonly(void) {}
diff --git a/iop/sound/libsd/Makefile b/iop/sound/libsd/Makefile
@@ -15,7 +15,7 @@ IOP_IMPORT_INCS += \
 	system/stdio \
 	system/sysclib
 
-IOP_OBJS = freesd.o batch.o block.o effect.o voice.o exports.o imports.o
+IOP_OBJS = exports.o freesd.o batch.o block.o effect.o voice.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/system/dmacman/Makefile b/iop/system/dmacman/Makefile
@@ -13,7 +13,7 @@ IOP_IMPORT_INCS += \
 	system/loadcore \
 	system/sysmem
 
-IOP_OBJS = dmacman.o exports.o imports.o
+IOP_OBJS = exports.o dmacman.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/system/intrman/Makefile b/iop/system/intrman/Makefile
@@ -15,7 +15,7 @@ IOP_IMPORT_INCS += \
 	system/excepman \
 	system/loadcore
 
-IOP_OBJS = intrman.o exports.o imports.o
+IOP_OBJS = exports.o intrman.o imports.o
 
 ifneq (x$(INTRMAN_PS1),x0)
 IOP_CFLAGS += -DBUILDING_INTRMANP
diff --git a/iop/system/mtapman/Makefile b/iop/system/mtapman/Makefile
@@ -16,7 +16,7 @@ IOP_IMPORT_INCS += \
 	system/stdio \
 	system/threadman
 
-IOP_OBJS = freemtap.o rpcservers.o exports.o imports.o
+IOP_OBJS = exports.o freemtap.o rpcservers.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/system/siftoo/Makefile b/iop/system/siftoo/Makefile
@@ -13,7 +13,7 @@ IOP_IMPORT_INCS += \
 	system/sifman \
 	system/stdio
 
-IOP_OBJS = siftoo.o pipe.o exports.o imports.o
+IOP_OBJS = exports.o siftoo.o pipe.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/system/stdio/Makefile b/iop/system/stdio/Makefile
@@ -13,7 +13,7 @@ IOP_IMPORT_INCS += \
 	system/loadcore \
 	system/sysclib
 
-IOP_OBJS = stdio.o exports.o imports.o
+IOP_OBJS = exports.o stdio.o imports.o
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/system/timrman/Makefile b/iop/system/timrman/Makefile
@@ -15,7 +15,7 @@ IOP_IMPORT_INCS += \
 	system/intrman \
 	system/loadcore
 
-IOP_OBJS = timrman.o imports.o exports.o
+IOP_OBJS = exports.o timrman.o imports.o
 
 ifneq (x$(TIMRMAN_PS1),x0)
 IOP_CFLAGS += -DBUILDING_TIMRMANP
diff --git a/iop/tcpip/tcpip-netman/src/exports.tab b/iop/tcpip/tcpip-netman/src/exports.tab
@@ -1,5 +1,3 @@
-void _retonly(void){}
-
 DECLARE_EXPORT_TABLE(ps2ip, 2, 6)
 	DECLARE_EXPORT(_start)
 	DECLARE_EXPORT(_retonly)
@@ -70,3 +68,5 @@ DECLARE_EXPORT_TABLE(ps2ip, 2, 6)
 	DECLARE_EXPORT(tcpip_callback_with_block)
 	DECLARE_EXPORT(pbuf_coalesce)
 END_EXPORT_TABLE
+
+void _retonly(void) {}
diff --git a/iop/tcpip/tcpip/Makefile b/iop/tcpip/tcpip/Makefile
@@ -57,7 +57,7 @@ ifdef PS2IP_DNS
 ps2ip_OBJECTS += dns.o netdb.o
 endif
 
-IOP_OBJS = ps2ip.o sys_arch.o exports.o imports.o $(ps2ip_OBJECTS)
+IOP_OBJS = exports.o ps2ip.o sys_arch.o imports.o $(ps2ip_OBJECTS)
 
 include $(PS2SDKSRC)/Defs.make
 include $(PS2SDKSRC)/iop/Rules.bin.make
diff --git a/iop/tcpip/tcpip/src/exports.tab b/iop/tcpip/tcpip/src/exports.tab
@@ -1,5 +1,3 @@
-void _retonly(void){}
-
 DECLARE_EXPORT_TABLE(ps2ip, 2, 6)
 	DECLARE_EXPORT(_start)
 	DECLARE_EXPORT(_retonly)
@@ -70,3 +68,5 @@ DECLARE_EXPORT_TABLE(ps2ip, 2, 6)
 	DECLARE_EXPORT(tcpip_callback_with_block)
 	DECLARE_EXPORT(pbuf_coalesce)
 END_EXPORT_TABLE
+
+void _retonly(void) {}
diff --git a/tools/srxfixup/README.md b/tools/srxfixup/README.md
@@ -26,3 +26,31 @@ This tool provides the following:
 
 To see usage and possible command line arguments that can be used with the
 program, run it without arguments.
+
+## Zero-.text symbol check
+
+When processing a relocatable ELF (`ET_REL`), `srxfixup` checks for function
+or no-type symbols in the `.text` section whose `st_value` is exactly 0.  Such
+symbols indicate that real code was placed first in `.text` by the linker.
+If an IOP export table has a zeroed or uninitialized entry, the dispatcher
+will issue a `jal 0x0` — silently jumping into whatever function sits at
+`.text` offset 0 instead of faulting.  The symbols `_start` and `_ftext` are
+excluded because they are entry points / linker labels that are never
+dispatched through an export table.
+
+If any offending symbol is found, `srxfixup` prints an error like:
+
+```
+ERROR: foo.irx: symbol 'bar' (sym#3) is in .text with value 0 -- if this module has an export table, put exports.o first in IOP_OBJS and move _retonly after DECLARE_EXPORT_TABLE in exports.tab; otherwise use --allow-zero-text.
+```
+
+and exits with a non-zero status so the build fails.
+
+For modules **with** an export table, the fix is to ensure `exports.o` is
+first in `IOP_OBJS` and that the `_retonly` definition appears after
+`DECLARE_EXPORT_TABLE` in `exports.tab`.  This places the export-table struct
+(`STT_OBJECT`) at `.text` offset 0 instead of function code.
+
+For modules **without** an export table, the `jal 0x0` hazard does not apply.
+Use `--allow-zero-text` to suppress the check.  The IOP `Rules.make`
+automatically passes this flag when `exports.o` is not present in `IOP_OBJS`.
diff --git a/tools/srxfixup/src/srxfixup.c b/tools/srxfixup/src/srxfixup.c
