[PATCH AUTOSEL 6.6 11/17] modpost: fix section mismatch message for RELA

[PATCH AUTOSEL 6.6 11/17] modpost: fix section mismatch message for RELA

[Sasha Levin]

From: Masahiro Yamada <masahiroy@kernel.org>

[ Upstream commit 1c4a7587d1bbee0fd53b63af60e4244a62775f57 ]

The section mismatch check prints a bogus symbol name on some
architectures.

[test code]

  #include <linux/init.h>

  int __initdata foo;
  int get_foo(void) { return foo; }

If you compile it with GCC for riscv or loongarch, modpost will show an
incorrect symbol name:

  WARNING: modpost: vmlinux: section mismatch in reference: get_foo+0x8 (section: .text) -> done (section: .init.data)

To get the correct symbol address, the st_value must be added.

This issue has never been noticed since commit 93684d3b8062 ("kbuild:
include symbol names in section mismatch warnings") presumably because
st_value becomes zero on most architectures when the referenced symbol
is looked up. It is not true for riscv or loongarch, at least.

With this fix, modpost will show the correct symbol name:

  WARNING: modpost: vmlinux: section mismatch in reference: get_foo+0x8 (section: .text) -> foo (section: .init.data)

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 scripts/mod/modpost.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index b3dee80497cb2..ac4ef3e206bbd 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1496,13 +1496,15 @@ static void section_rela(struct module *mod, struct elf_info *elf,
 		return;
 
 	for (rela = start; rela < stop; rela++) {
+		Elf_Sym *tsym;
 		Elf_Addr taddr, r_offset;
 		unsigned int r_type, r_sym;
 
 		r_offset = TO_NATIVE(rela->r_offset);
 		get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
 
-		taddr = TO_NATIVE(rela->r_addend);
+		tsym = elf->symtab_start + r_sym;
+		taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
 
 		switch (elf->hdr->e_machine) {
 		case EM_RISCV:
@@ -1517,7 +1519,7 @@ static void section_rela(struct module *mod, struct elf_info *elf,
 			break;
 		}
 
-		check_section_mismatch(mod, elf, elf->symtab_start + r_sym,
+		check_section_mismatch(mod, elf, tsym,
 				       fsecndx, fromsec, r_offset, taddr);
 	}
 }
-- 
2.42.0

[PATCH AUTOSEL 6.6 13/17] kconfig: fix memory leak from range properties

[Sasha Levin]

From: Masahiro Yamada <masahiroy@kernel.org>

[ Upstream commit ae1eff0349f2e908fc083630e8441ea6dc434dc0 ]

Currently, sym_validate_range() duplicates the range string using
xstrdup(), which is overwritten by a subsequent sym_calc_value() call.
It results in a memory leak.

Instead, only the pointer should be copied.

Below is a test case, with a summary from Valgrind.

[Test Kconfig]

  config FOO
          int "foo"
          range 10 20

[Test .config]

  CONFIG_FOO=0

[Before]

  LEAK SUMMARY:
     definitely lost: 3 bytes in 1 blocks
     indirectly lost: 0 bytes in 0 blocks
       possibly lost: 0 bytes in 0 blocks
     still reachable: 17,465 bytes in 21 blocks
          suppressed: 0 bytes in 0 blocks

[After]

  LEAK SUMMARY:
     definitely lost: 0 bytes in 0 blocks
     indirectly lost: 0 bytes in 0 blocks
       possibly lost: 0 bytes in 0 blocks
     still reachable: 17,462 bytes in 20 blocks
          suppressed: 0 bytes in 0 blocks

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 scripts/kconfig/symbol.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 0572330bf8a78..a76925b46ce63 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -122,9 +122,9 @@ static long long sym_get_range_val(struct symbol *sym, int base)
 static void sym_validate_range(struct symbol *sym)
 {
 	struct property *prop;
+	struct symbol *range_sym;
 	int base;
 	long long val, val2;
-	char str[64];
 
 	switch (sym->type) {
 	case S_INT:
@@ -140,17 +140,15 @@ static void sym_validate_range(struct symbol *sym)
 	if (!prop)
 		return;
 	val = strtoll(sym->curr.val, NULL, base);
-	val2 = sym_get_range_val(prop->expr->left.sym, base);
+	range_sym = prop->expr->left.sym;
+	val2 = sym_get_range_val(range_sym, base);
 	if (val >= val2) {
-		val2 = sym_get_range_val(prop->expr->right.sym, base);
+		range_sym = prop->expr->right.sym;
+		val2 = sym_get_range_val(range_sym, base);
 		if (val <= val2)
 			return;
 	}
-	if (sym->type == S_INT)
-		sprintf(str, "%lld", val2);
-	else
-		sprintf(str, "0x%llx", val2);
-	sym->curr.val = xstrdup(str);
+	sym->curr.val = range_sym->curr.val;
 }
 
 static void sym_set_changed(struct symbol *sym)
-- 
2.42.0