[PATCH 4.19 84/96] modpost: file2alias: go back to simple devtable lookup

Greg Kroah-Hartman
2019-04-24T17:46:13Z

[ Upstream commit ec91e78d378cc5d4b43805a1227d8e04e5dfa17d ]

Commit e49ce14150c6 ("modpost: use linker section to generate table.")
was not so cool as we had expected first; it ended up with ugly section
hacks when commit dd2a3acaecd7 ("mod/file2alias: make modpost compile
on darwin again") came in.

Given a certain degree of unknowledge about the link stage of host
programs, I really want to see simple, stupid table lookup so that
this works in the same way regardless of the underlying executable
format.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
scripts/mod/file2alias.c | 144 +++++++++++++--------------------------
1 file changed, 49 insertions(+), 95 deletions(-)

diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 7be43697ff84..9f3ebde7a0cd 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -50,46 +50,6 @@ struct devtable {
void *function;
};

-#define ___cat(a,b) a ## b
-#define __cat(a,b) ___cat(a,b)
-
-/* we need some special handling for this host tool running eventually on
- * Darwin. The Mach-O section handling is a bit different than ELF section
- * handling. The differnces in detail are:
- * a) we have segments which have sections
- * b) we need a API call to get the respective section symbols */
-#if defined(__MACH__)
-#include <mach-o/getsect.h>
-
-#define INIT_SECTION(name) do { \
- unsigned long name ## _len; \
- char *__cat(pstart_,name) = getsectdata("__TEXT", \
- #name, &__cat(name,_len)); \
- char *__cat(pstop_,name) = __cat(pstart_,name) + \
- __cat(name, _len); \
- __cat(__start_,name) = (void *)__cat(pstart_,name); \
- __cat(__stop_,name) = (void *)__cat(pstop_,name); \
- } while (0)
-#define SECTION(name) __attribute__((section("__TEXT, " #name)))
-
-struct devtable **__start___devtable, **__stop___devtable;
-#else
-#define INIT_SECTION(name) /* no-op for ELF */
-#define SECTION(name) __attribute__((section(#name)))
-
-/* We construct a table of pointers in an ELF section (pointers generally
- * go unpadded by gcc). ld creates boundary syms for us. */
-extern struct devtable *__start___devtable[], *__stop___devtable[];
-#endif /* __MACH__ */
-
-#if !defined(__used)
-# if __GNUC__ == 3 && __GNUC_MINOR__ < 3
-# define __used __attribute__((__unused__))
-# else
-# define __used __attribute__((__used__))
-# endif
-#endif
-
/* Define a variable f that holds the value of field f of struct devid
* based at address m.
*/
@@ -102,16 +62,6 @@ extern struct devtable *__start___devtable[], *__stop___devtable[];
#define DEF_FIELD_ADDR(m, devid, f) \
typeof(((struct devid *)0)->f) *f = ((m) + OFF_##devid##_##f)

-/* Add a table entry. We test function type matches while we're here. */
-#define ADD_TO_DEVTABLE(device_id, type, function) \
- static struct devtable __cat(devtable,__LINE__) = { \
- device_id + 0*sizeof((function)((const char *)NULL, \
- (void *)NULL, \
- (char *)NULL)), \
- SIZE_##type, (function) }; \
- static struct devtable *SECTION(__devtable) __used \
- __cat(devtable_ptr,__LINE__) = &__cat(devtable,__LINE__)
-
#define ADD(str, sep, cond, field) \
do { \
strcat(str, sep); \
@@ -431,7 +381,6 @@ static int do_hid_entry(const char *filename,

return 1;
}
-ADD_TO_DEVTABLE("hid", hid_device_id, do_hid_entry);

/* Looks like: ieee1394:venNmoNspNverN */
static int do_ieee1394_entry(const char *filename,
@@ -456,7 +405,6 @@ static int do_ieee1394_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("ieee1394", ieee1394_device_id, do_ieee1394_entry);

/* Looks like: pci:vNdNsvNsdNbcNscNiN. */
static int do_pci_entry(const char *filename,
@@ -500,7 +448,6 @@ static int do_pci_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("pci", pci_device_id, do_pci_entry);

/* looks like: "ccw:tNmNdtNdmN" */
static int do_ccw_entry(const char *filename,
@@ -524,7 +471,6 @@ static int do_ccw_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("ccw", ccw_device_id, do_ccw_entry);

/* looks like: "ap:tN" */
static int do_ap_entry(const char *filename,
@@ -535,7 +481,6 @@ static int do_ap_entry(const char *filename,
sprintf(alias, "ap:t%02X*", dev_type);
return 1;
}
-ADD_TO_DEVTABLE("ap", ap_device_id, do_ap_entry);

/* looks like: "css:tN" */
static int do_css_entry(const char *filename,
@@ -546,7 +491,6 @@ static int do_css_entry(const char *filename,
sprintf(alias, "css:t%01X", type);
return 1;
}
-ADD_TO_DEVTABLE("css", css_device_id, do_css_entry);

/* Looks like: "serio:tyNprNidNexN" */
static int do_serio_entry(const char *filename,
@@ -566,7 +510,6 @@ static int do_serio_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("serio", serio_device_id, do_serio_entry);

/* looks like: "acpi:ACPI0003" or "acpi:PNP0C0B" or "acpi:LNXVIDEO" or
* "acpi:bbsspp" (bb=base-class, ss=sub-class, pp=prog-if)
@@ -604,7 +547,6 @@ static int do_acpi_entry(const char *filename,
}
return 1;
}
-ADD_TO_DEVTABLE("acpi", acpi_device_id, do_acpi_entry);

/* looks like: "pnp:dD" */
static void do_pnp_device_entry(void *symval, unsigned long size,
@@ -725,7 +667,6 @@ static int do_pcmcia_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("pcmcia", pcmcia_device_id, do_pcmcia_entry);

static int do_vio_entry(const char *filename, void *symval,
char *alias)
@@ -745,7 +686,6 @@ static int do_vio_entry(const char *filename, void *symval,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("vio", vio_device_id, do_vio_entry);

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

@@ -818,7 +758,6 @@ static int do_input_entry(const char *filename, void *symval,
do_input(alias, *swbit, 0, INPUT_DEVICE_ID_SW_MAX);
return 1;
}
-ADD_TO_DEVTABLE("input", input_device_id, do_input_entry);

static int do_eisa_entry(const char *filename, void *symval,
char *alias)
@@ -830,7 +769,6 @@ static int do_eisa_entry(const char *filename, void *symval,
strcat(alias, "*");
return 1;
}
-ADD_TO_DEVTABLE("eisa", eisa_device_id, do_eisa_entry);

/* Looks like: parisc:tNhvNrevNsvN */
static int do_parisc_entry(const char *filename, void *symval,
@@ -850,7 +788,6 @@ static int do_parisc_entry(const char *filename, void *symval,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("parisc", parisc_device_id, do_parisc_entry);

/* Looks like: sdio:cNvNdN. */
static int do_sdio_entry(const char *filename,
@@ -867,7 +804,6 @@ static int do_sdio_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("sdio", sdio_device_id, do_sdio_entry);

/* Looks like: ssb:vNidNrevN. */
static int do_ssb_entry(const char *filename,
@@ -884,7 +820,6 @@ static int do_ssb_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("ssb", ssb_device_id, do_ssb_entry);

/* Looks like: bcma:mNidNrevNclN. */
static int do_bcma_entry(const char *filename,
@@ -903,7 +838,6 @@ static int do_bcma_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("bcma", bcma_device_id, do_bcma_entry);

/* Looks like: virtio:dNvN */
static int do_virtio_entry(const char *filename, void *symval,
@@ -919,7 +853,6 @@ static int do_virtio_entry(const char *filename, void *symval,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("virtio", virtio_device_id, do_virtio_entry);

/*
* Looks like: vmbus:guid
@@ -942,7 +875,6 @@ static int do_vmbus_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("vmbus", hv_vmbus_device_id, do_vmbus_entry);

/* Looks like: rpmsg:S */
static int do_rpmsg_entry(const char *filename, void *symval,
@@ -953,7 +885,6 @@ static int do_rpmsg_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("rpmsg", rpmsg_device_id, do_rpmsg_entry);

/* Looks like: i2c:S */
static int do_i2c_entry(const char *filename, void *symval,
@@ -964,7 +895,6 @@ static int do_i2c_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("i2c", i2c_device_id, do_i2c_entry);

/* Looks like: spi:S */
static int do_spi_entry(const char *filename, void *symval,
@@ -975,7 +905,6 @@ static int do_spi_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("spi", spi_device_id, do_spi_entry);

static const struct dmifield {
const char *prefix;
@@ -1030,7 +959,6 @@ static int do_dmi_entry(const char *filename, void *symval,
strcat(alias, ":");
return 1;
}
-ADD_TO_DEVTABLE("dmi", dmi_system_id, do_dmi_entry);

static int do_platform_entry(const char *filename,
void *symval, char *alias)
@@ -1039,7 +967,6 @@ static int do_platform_entry(const char *filename,
sprintf(alias, PLATFORM_MODULE_PREFIX "%s", *name);
return 1;
}
-ADD_TO_DEVTABLE("platform", platform_device_id, do_platform_entry);

static int do_mdio_entry(const char *filename,
void *symval, char *alias)
@@ -1064,7 +991,6 @@ static int do_mdio_entry(const char *filename,

return 1;
}
-ADD_TO_DEVTABLE("mdio", mdio_device_id, do_mdio_entry);

/* Looks like: zorro:iN. */
static int do_zorro_entry(const char *filename, void *symval,
@@ -1075,7 +1001,6 @@ static int do_zorro_entry(const char *filename, void *symval,
ADD(alias, "i", id != ZORRO_WILDCARD, id);
return 1;
}
-ADD_TO_DEVTABLE("zorro", zorro_device_id, do_zorro_entry);

/* looks like: "pnp:dD" */
static int do_isapnp_entry(const char *filename,
@@ -1091,7 +1016,6 @@ static int do_isapnp_entry(const char *filename,
(function >> 12) & 0x0f, (function >> 8) & 0x0f);
return 1;
}
-ADD_TO_DEVTABLE("isapnp", isapnp_device_id, do_isapnp_entry);

/* Looks like: "ipack:fNvNdN". */
static int do_ipack_entry(const char *filename,
@@ -1107,7 +1031,6 @@ static int do_ipack_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("ipack", ipack_device_id, do_ipack_entry);

/*
* Append a match expression for a single masked hex digit.
@@ -1178,7 +1101,6 @@ static int do_amba_entry(const char *filename,

return 1;
}
-ADD_TO_DEVTABLE("amba", amba_id, do_amba_entry);

/*
* looks like: "mipscdmm:tN"
@@ -1194,7 +1116,6 @@ static int do_mips_cdmm_entry(const char *filename,
sprintf(alias, "mipscdmm:t%02X*", type);
return 1;
}
-ADD_TO_DEVTABLE("mipscdmm", mips_cdmm_device_id, do_mips_cdmm_entry);

/* LOOKS like cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:*,FEAT,*
* All fields are numbers. It would be nicer to use strings for vendor
@@ -1219,7 +1140,6 @@ static int do_x86cpu_entry(const char *filename, void *symval,
sprintf(alias + strlen(alias), "%04X*", feature);
return 1;
}
-ADD_TO_DEVTABLE("x86cpu", x86_cpu_id, do_x86cpu_entry);

/* LOOKS like cpu:type:*:feature:*FEAT* */
static int do_cpu_entry(const char *filename, void *symval, char *alias)
@@ -1229,7 +1149,6 @@ static int do_cpu_entry(const char *filename, void *symval, char *alias)
sprintf(alias, "cpu:type:*:feature:*%04X*", feature);
return 1;
}
-ADD_TO_DEVTABLE("cpu", cpu_feature, do_cpu_entry);

/* Looks like: mei:S:uuid:N:* */
static int do_mei_entry(const char *filename, void *symval,
@@ -1248,7 +1167,6 @@ static int do_mei_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("mei", mei_cl_device_id, do_mei_entry);

/* Looks like: rapidio:vNdNavNadN */
static int do_rio_entry(const char *filename,
@@ -1268,7 +1186,6 @@ static int do_rio_entry(const char *filename,
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("rapidio", rio_device_id, do_rio_entry);

/* Looks like: ulpi:vNpN */
static int do_ulpi_entry(const char *filename, void *symval,
@@ -1281,7 +1198,6 @@ static int do_ulpi_entry(const char *filename, void *symval,

return 1;
}
-ADD_TO_DEVTABLE("ulpi", ulpi_device_id, do_ulpi_entry);

/* Looks like: hdaudio:vNrNaN */
static int do_hda_entry(const char *filename, void *symval, char *alias)
@@ -1298,7 +1214,6 @@ static int do_hda_entry(const char *filename, void *symval, char *alias)
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("hdaudio", hda_device_id, do_hda_entry);

/* Looks like: sdw:mNpN */
static int do_sdw_entry(const char *filename, void *symval, char *alias)
@@ -1313,7 +1228,6 @@ static int do_sdw_entry(const char *filename, void *symval, char *alias)
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("sdw", sdw_device_id, do_sdw_entry);

/* Looks like: fsl-mc:vNdN */
static int do_fsl_mc_entry(const char *filename, void *symval,
@@ -1325,7 +1239,6 @@ static int do_fsl_mc_entry(const char *filename, void *symval,
sprintf(alias, "fsl-mc:v%08Xd%s", vendor, *obj_type);
return 1;
}
-ADD_TO_DEVTABLE("fslmc", fsl_mc_device_id, do_fsl_mc_entry);

/* Looks like: tbsvc:kSpNvNrN */
static int do_tbsvc_entry(const char *filename, void *symval, char *alias)
@@ -1350,7 +1263,6 @@ static int do_tbsvc_entry(const char *filename, void *symval, char *alias)
add_wildcard(alias);
return 1;
}
-ADD_TO_DEVTABLE("tbsvc", tb_service_id, do_tbsvc_entry);

/* Looks like: typec:idNmN */
static int do_typec_entry(const char *filename, void *symval, char *alias)
@@ -1363,7 +1275,6 @@ static int do_typec_entry(const char *filename, void *symval, char *alias)

return 1;
}
-ADD_TO_DEVTABLE("typec", typec_device_id, do_typec_entry);

/* Does namelen bytes of name exactly match the symbol? */
static bool sym_is(const char *name, unsigned namelen, const char *symbol)
@@ -1396,6 +1307,48 @@ static void do_table(void *symval, unsigned long size,
}
}

+static const struct devtable devtable[] = {
+ {"hid", SIZE_hid_device_id, do_hid_entry},
+ {"ieee1394", SIZE_ieee1394_device_id, do_ieee1394_entry},
+ {"pci", SIZE_pci_device_id, do_pci_entry},
+ {"ccw", SIZE_ccw_device_id, do_ccw_entry},
+ {"ap", SIZE_ap_device_id, do_ap_entry},
+ {"css", SIZE_css_device_id, do_css_entry},
+ {"serio", SIZE_serio_device_id, do_serio_entry},
+ {"acpi", SIZE_acpi_device_id, do_acpi_entry},
+ {"pcmcia", SIZE_pcmcia_device_id, do_pcmcia_entry},
+ {"vio", SIZE_vio_device_id, do_vio_entry},
+ {"input", SIZE_input_device_id, do_input_entry},
+ {"eisa", SIZE_eisa_device_id, do_eisa_entry},
+ {"parisc", SIZE_parisc_device_id, do_parisc_entry},
+ {"sdio", SIZE_sdio_device_id, do_sdio_entry},
+ {"ssb", SIZE_ssb_device_id, do_ssb_entry},
+ {"bcma", SIZE_bcma_device_id, do_bcma_entry},
+ {"virtio", SIZE_virtio_device_id, do_virtio_entry},
+ {"vmbus", SIZE_hv_vmbus_device_id, do_vmbus_entry},
+ {"rpmsg", SIZE_rpmsg_device_id, do_rpmsg_entry},
+ {"i2c", SIZE_i2c_device_id, do_i2c_entry},
+ {"spi", SIZE_spi_device_id, do_spi_entry},
+ {"dmi", SIZE_dmi_system_id, do_dmi_entry},
+ {"platform", SIZE_platform_device_id, do_platform_entry},
+ {"mdio", SIZE_mdio_device_id, do_mdio_entry},
+ {"zorro", SIZE_zorro_device_id, do_zorro_entry},
+ {"isapnp", SIZE_isapnp_device_id, do_isapnp_entry},
+ {"ipack", SIZE_ipack_device_id, do_ipack_entry},
+ {"amba", SIZE_amba_id, do_amba_entry},
+ {"mipscdmm", SIZE_mips_cdmm_device_id, do_mips_cdmm_entry},
+ {"x86cpu", SIZE_x86_cpu_id, do_x86cpu_entry},
+ {"cpu", SIZE_cpu_feature, do_cpu_entry},
+ {"mei", SIZE_mei_cl_device_id, do_mei_entry},
+ {"rapidio", SIZE_rio_device_id, do_rio_entry},
+ {"ulpi", SIZE_ulpi_device_id, do_ulpi_entry},
+ {"hdaudio", SIZE_hda_device_id, do_hda_entry},
+ {"sdw", SIZE_sdw_device_id, do_sdw_entry},
+ {"fslmc", SIZE_fsl_mc_device_id, do_fsl_mc_entry},
+ {"tbsvc", SIZE_tb_service_id, do_tbsvc_entry},
+ {"typec", SIZE_typec_device_id, do_typec_entry},
+};
+
/* Create MODULE_ALIAS() statements.
* At this time, we cannot write the actual output C source yet,
* so we write into the mod->dev_table_buf buffer. */
@@ -1450,13 +1403,14 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
else if (sym_is(name, namelen, "pnp_card"))
do_pnp_card_entries(symval, sym->st_size, mod);
else {
- struct devtable **p;
- INIT_SECTION(__devtable);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(devtable); i++) {
+ const struct devtable *p = &devtable[i];

- for (p = __start___devtable; p < __stop___devtable; p++) {
- if (sym_is(name, namelen, (*p)->device_id)) {
- do_table(symval, sym->st_size, (*p)->id_size,
- (*p)->device_id, (*p)->function, mod);
+ if (sym_is(name, namelen, p->device_id)) {
+ do_table(symval, sym->st_size, p->id_size,
+ p->device_id, p->function, mod);
break;
}
}
--
2.19.1