kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU

x86-64 was the only user.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250123190747.745588-16-brgerst@gmail.com

diff --git a/init/Kconfig b/init/Kconfig
index b5d9c0fa69f6787bc0e78a27d445a4785a55e5c5..a0ea04c1778428cc1864147bb0d85793c2334988 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1869,11 +1869,6 @@ config KALLSYMS_ALL
 
          Say N unless you really need all symbols, or kernel live patching.
 
-config KALLSYMS_ABSOLUTE_PERCPU
-       bool
-       depends on KALLSYMS
-       default n
-
 # end of the "standard kernel features (expert users)" menu
 
 config ARCH_HAS_MEMBARRIER_CALLBACKS

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a9a0ca605d4a8c82c5575706443287120ee6edc4..4198f30aac3cabe6b782751725e4bdcfee7af4db 100644 (file)
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -148,16 +148,8 @@ static unsigned int get_symbol_offset(unsigned long pos)
 
 unsigned long kallsyms_sym_address(int idx)
 {
-       /* values are unsigned offsets if --absolute-percpu is not in effect */
-       if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
-               return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
-
-       /* ...otherwise, positive offsets are absolute values */
-       if (kallsyms_offsets[idx] >= 0)
-               return kallsyms_offsets[idx];
-
-       /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
-       return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
+       /* values are unsigned offsets */
+       return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
 }
 
 static unsigned int get_symbol_seq(int index)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 03852da3d24904e9327234b7a93311b5c1d71b82..4b0234e4b12f3275491257f954f46ee6efacaab8 100644 (file)
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -5,7 +5,7 @@
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
- * Usage: kallsyms [--all-symbols] [--absolute-percpu]  in.map > out.S
+ * Usage: kallsyms [--all-symbols] in.map > out.S
  *
  *      Table compression uses all the unused char codes on the symbols and
  *  maps these to the most used substrings (tokens). For instance, it might
@@ -37,7 +37,6 @@ struct sym_entry {
        unsigned long long addr;
        unsigned int len;
        unsigned int seq;
-       bool percpu_absolute;
        unsigned char sym[];
 };
 
@@ -55,14 +54,9 @@ static struct addr_range text_ranges[] = {
 #define text_range_text     (&text_ranges[0])
 #define text_range_inittext (&text_ranges[1])
 
-static struct addr_range percpu_range = {
-       "__per_cpu_start", "__per_cpu_end", -1ULL, 0
-};
-
 static struct sym_entry **table;
 static unsigned int table_size, table_cnt;
 static int all_symbols;
-static int absolute_percpu;
 
 static int token_profit[0x10000];
 
@@ -73,7 +67,7 @@ static unsigned char best_table_len[256];
 
 static void usage(void)
 {
-       fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] in.map > out.S\n");
+       fprintf(stderr, "Usage: kallsyms [--all-symbols] in.map > out.S\n");
        exit(1);
 }
 
@@ -164,7 +158,6 @@ static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
                return NULL;
 
        check_symbol_range(name, addr, text_ranges, ARRAY_SIZE(text_ranges));
-       check_symbol_range(name, addr, &percpu_range, 1);
 
        /* include the type field in the symbol name, so that it gets
         * compressed together */
@@ -175,7 +168,6 @@ static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
        sym->len = len;
        sym->sym[0] = type;
        strcpy(sym_name(sym), name);
-       sym->percpu_absolute = false;
 
        return sym;
 }
@@ -319,11 +311,6 @@ static int expand_symbol(const unsigned char *data, int len, char *result)
        return total;
 }
 
-static bool symbol_absolute(const struct sym_entry *s)
-{
-       return s->percpu_absolute;
-}
-
 static int compare_names(const void *a, const void *b)
 {
        int ret;
@@ -455,22 +442,11 @@ static void write_src(void)
                 */
 
                long long offset;
-               bool overflow;
-
-               if (!absolute_percpu) {
-                       offset = table[i]->addr - relative_base;
-                       overflow = offset < 0 || offset > UINT_MAX;
-               } else if (symbol_absolute(table[i])) {
-                       offset = table[i]->addr;
-                       overflow = offset < 0 || offset > INT_MAX;
-               } else {
-                       offset = relative_base - table[i]->addr - 1;
-                       overflow = offset < INT_MIN || offset >= 0;
-               }
-               if (overflow) {
+
+               offset = table[i]->addr - relative_base;
+               if (offset < 0 || offset > UINT_MAX) {
                        fprintf(stderr, "kallsyms failure: "
-                               "%s symbol value %#llx out of range in relative mode\n",
-                               symbol_absolute(table[i]) ? "absolute" : "relative",
+                               "relative symbol value %#llx out of range\n",
                                table[i]->addr);
                        exit(EXIT_FAILURE);
                }
@@ -725,36 +701,15 @@ static void sort_symbols(void)
        qsort(table, table_cnt, sizeof(table[0]), compare_symbols);
 }
 
-static void make_percpus_absolute(void)
-{
-       unsigned int i;
-
-       for (i = 0; i < table_cnt; i++)
-               if (symbol_in_range(table[i], &percpu_range, 1)) {
-                       /*
-                        * Keep the 'A' override for percpu symbols to
-                        * ensure consistent behavior compared to older
-                        * versions of this tool.
-                        */
-                       table[i]->sym[0] = 'A';
-                       table[i]->percpu_absolute = true;
-               }
-}
-
 /* find the minimum non-absolute symbol address */
 static void record_relative_base(void)
 {
-       unsigned int i;
-
-       for (i = 0; i < table_cnt; i++)
-               if (!symbol_absolute(table[i])) {
-                       /*
-                        * The table is sorted by address.
-                        * Take the first non-absolute symbol value.
-                        */
-                       relative_base = table[i]->addr;
-                       return;
-               }
+       /*
+        * The table is sorted by address.
+        * Take the first symbol value.
+        */
+       if (table_cnt)
+               relative_base = table[0]->addr;
 }
 
 int main(int argc, char **argv)
@@ -762,7 +717,6 @@ int main(int argc, char **argv)
        while (1) {
                static const struct option long_options[] = {
                        {"all-symbols",     no_argument, &all_symbols,     1},
-                       {"absolute-percpu", no_argument, &absolute_percpu, 1},
                        {},
                };
 
@@ -779,8 +733,6 @@ int main(int argc, char **argv)
 
        read_map(argv[optind]);
        shrink_table();
-       if (absolute_percpu)
-               make_percpus_absolute();
        sort_symbols();
        record_relative_base();
        optimize_token_table();

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 56a077d204cfa1b67609cf0ea4a8ebe5f5884f03..67e66333bd2a3cda10a74d5efebef7e92c3ede49 100755 (executable)
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -144,10 +144,6 @@ kallsyms()
                kallsymopt="${kallsymopt} --all-symbols"
        fi
 
-       if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
-               kallsymopt="${kallsymopt} --absolute-percpu"
-       fi
-
        info KSYMS "${2}.S"
        scripts/kallsyms ${kallsymopt} "${1}" > "${2}.S"