diff options
Diffstat (limited to 'tools/com-plugin')
| -rw-r--r-- | tools/com-plugin/.gitrepo | 4 | ||||
| -rw-r--r-- | tools/com-plugin/README.md | 2 | ||||
| -rw-r--r-- | tools/com-plugin/plugin.c | 52 |
3 files changed, 53 insertions, 5 deletions
diff --git a/tools/com-plugin/.gitrepo b/tools/com-plugin/.gitrepo index 6215d5759..f161950b7 100644 --- a/tools/com-plugin/.gitrepo +++ b/tools/com-plugin/.gitrepo @@ -6,7 +6,7 @@ [subrepo] remote = git@github.com:Thar0/com-plugin.git branch = main - commit = fc5aa5eda0b09e8e3cf91ce1530f886bb1ab8eef - parent = 54939bac3ac972a24918d3fdc97d58199ff54bc9 + commit = c4f3ba845a386a254c912a4ceb780371f9a66722 + parent = 77827c25b63e7a292ca45eee6bceeda7c8600af4 method = merge cmdver = 0.4.6 diff --git a/tools/com-plugin/README.md b/tools/com-plugin/README.md index 1db9e481e..923e67c05 100644 --- a/tools/com-plugin/README.md +++ b/tools/com-plugin/README.md @@ -10,6 +10,8 @@ The plugin expects a symbol order txt file listing the COMMON symbols in order o Add `-plugin common-plugin.so -plugin-opt order=bss_order.txt` to the linker invocation, replacing `bss_order.txt` with an alternative path if desired. +An optional argument `-plugin-opt min_align=N` can specify the minimum alignment for the bss output files. If unset, the minimum alignment is 0: the resulting section alignment is equal to the minimum alignment required by the symbols. + Also add any bss output files mentioned in the order file to the linker script (e.g. `bss.o` would be added as `*bss.o(.bss*)`) so that the additional input file is not discarded, if required. ### **Symbol order file syntax** diff --git a/tools/com-plugin/plugin.c b/tools/com-plugin/plugin.c index cd1fa0a53..91db2aa17 100644 --- a/tools/com-plugin/plugin.c +++ b/tools/com-plugin/plugin.c @@ -70,12 +70,13 @@ static struct { size_t num_ofiles; // Our options char *order_path; + size_t min_align; // LD plugin int api_version; int gnu_ld_version; int linker_output; const char *output_name; - ld_plugin_message message; + ld_plugin_message message __attribute__((format(printf, 2, 3))); ld_plugin_add_symbols add_symbols; ld_plugin_get_symbols get_symbols; ld_plugin_get_symbols get_symbols_v2; @@ -339,6 +340,8 @@ all_symbols_read(void) sym_offset += be32toh(sym->st_size); } + if (greatest_align < pl.min_align) + greatest_align = pl.min_align; sym_offset = (sym_offset + greatest_align - 1) & ~(greatest_align - 1); size_t symtab_size = ftell(elf) - symtab_offset; @@ -491,7 +494,7 @@ parse_order_file(const char *order_file) // Read the entire bss order file and null-terminate it FILE *bss_order = fopen(order_file, "rb"); if (bss_order == NULL) { - pl.message(LDPL_FATAL, "Could not open bss order file %s for reading: %s", bss_order, strerror(errno)); + pl.message(LDPL_FATAL, "Could not open bss order file \"%s\" for reading: %s", order_file, strerror(errno)); return LDPS_ERR; } @@ -501,7 +504,7 @@ parse_order_file(const char *order_file) pl.string_pool = malloc((fsize + 1) * sizeof(char)); if (fread(pl.string_pool, fsize, 1, bss_order) != 1) { - pl.message(LDPL_FATAL, "Failed to read bss order file %s: %s", order_file, strerror(errno)); + pl.message(LDPL_FATAL, "Failed to read bss order file \"%s\": %s", order_file, strerror(errno)); free(pl.string_pool); fclose(bss_order); return LDPS_ERR; @@ -716,12 +719,55 @@ syntaxerror: } static enum ld_plugin_status +read_int(size_t *out, const char *s) +{ + if (s[0] == '\0') + goto err; + + size_t res; + + size_t length = strlen(s); + size_t start = 0; + + // we expect unsigned input, error on - and skip + + if (s[start] == '-') + goto err; + if (s[start] == '+') + start++; + + // determine the base of the input via the presence of an 0x prefix + int base; + if (start + 2 < length && s[start + 0] == '0' && tolower(s[start + 1]) == 'x') { + start += 2; + base = 16; + } else { + base = 10; + } + + // read the value in the appropriate base + char *str_end; + res = strtoull(&s[start], &str_end, base); + size_t end = str_end - s; + if (start == end) + goto err; + + *out = res; + return LDPS_OK; +err: + fprintf(stderr, "Bad input to min_align, must be an unsigned integer in base 10 or 16: %s", s); + return LDPS_ERR; +} + +static enum ld_plugin_status parse_option(const char *opt) { if (strequ(opt, "order=")) { pl.order_path = strdup(opt + sizeof("order=") - 1); return LDPS_OK; } + if (strequ(opt, "min_align=")) { + return read_int(&pl.min_align, opt + sizeof("min_align=") - 1); + } fprintf(stderr, "Unknown option: %s\n", opt); return LDPS_ERR; |