drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 237 insertions, 0 deletions

diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
new file mode 100644
index 000000000..797f455eb
--- /dev/null
+++ b/tools/perf/util/dwarf-regs.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ *
+ * Written by: Masami Hiramatsu <mhiramat@kernel.org>
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <debug.h>
+#include <dwarf-regs.h>
+#include <elf.h>
+#include <errno.h>
+#include <linux/kernel.h>
+
+/* Define const char * {arch}_register_tbl[] */
+#define DEFINE_DWARF_REGSTR_TABLE
+#include "../arch/x86/include/dwarf-regs-table.h"
+#include "../arch/arm/include/dwarf-regs-table.h"
+#include "../arch/arm64/include/dwarf-regs-table.h"
+#include "../arch/sh/include/dwarf-regs-table.h"
+#include "../arch/powerpc/include/dwarf-regs-table.h"
+#include "../arch/riscv/include/dwarf-regs-table.h"
+#include "../arch/s390/include/dwarf-regs-table.h"
+#include "../arch/sparc/include/dwarf-regs-table.h"
+#include "../arch/xtensa/include/dwarf-regs-table.h"
+#include "../arch/mips/include/dwarf-regs-table.h"
+#include "../arch/loongarch/include/dwarf-regs-table.h"
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags)
+{
+	#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
+
+	if (machine == EM_NONE) {
+		/* Generic arch - use host arch */
+		machine = EM_HOST;
+	}
+	switch (machine) {
+	case EM_386:
+		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
+	case EM_X86_64:
+		return __get_dwarf_regstr(x86_64_regstr_tbl, n);
+	case EM_ARM:
+		return __get_dwarf_regstr(arm_regstr_tbl, n);
+	case EM_AARCH64:
+		return __get_dwarf_regstr(aarch64_regstr_tbl, n);
+	case EM_CSKY:
+		return __get_csky_regstr(n, flags);
+	case EM_SH:
+		return __get_dwarf_regstr(sh_regstr_tbl, n);
+	case EM_S390:
+		return __get_dwarf_regstr(s390_regstr_tbl, n);
+	case EM_PPC:
+	case EM_PPC64:
+		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
+	case EM_RISCV:
+		return __get_dwarf_regstr(riscv_regstr_tbl, n);
+	case EM_SPARC:
+	case EM_SPARCV9:
+		return __get_dwarf_regstr(sparc_regstr_tbl, n);
+	case EM_XTENSA:
+		return __get_dwarf_regstr(xtensa_regstr_tbl, n);
+	case EM_MIPS:
+		return __get_dwarf_regstr(mips_regstr_tbl, n);
+	case EM_LOONGARCH:
+		return __get_dwarf_regstr(loongarch_regstr_tbl, n);
+	default:
+		pr_err("ELF MACHINE %x is not supported.\n", machine);
+	}
+	return NULL;
+
+	#undef __get_dwarf_regstr
+}
+
+static int __get_dwarf_regnum(const char *const *regstr, size_t num_regstr, const char *name)
+{
+	for (size_t i = 0; i < num_regstr; i++) {
+		if (regstr[i] && !strcmp(regstr[i], name))
+			return i;
+	}
+	return -ENOENT;
+}
+
+/* Return DWARF register number from architecture register name */
+int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags)
+{
+	char *regname = strdup(name);
+	int reg = -1;
+	char *p;
+
+	#define _get_dwarf_regnum(tbl, name) __get_dwarf_regnum(tbl, ARRAY_SIZE(tbl), name)
+
+	if (regname == NULL)
+		return -EINVAL;
+
+	/* For convenience, remove trailing characters */
+	p = strpbrk(regname, " ,)");
+	if (p)
+		*p = '\0';
+
+	if (machine == EM_NONE) {
+		/* Generic arch - use host arch */
+		machine = EM_HOST;
+	}
+	switch (machine) {
+	case EM_X86_64:
+		reg = __get_dwarf_regnum_x86_64(name);
+		break;
+	case EM_386:
+		reg = __get_dwarf_regnum_i386(name);
+		break;
+	case EM_ARM:
+		reg = _get_dwarf_regnum(arm_regstr_tbl, name);
+		break;
+	case EM_AARCH64:
+		reg = _get_dwarf_regnum(aarch64_regstr_tbl, name);
+		break;
+	case EM_CSKY:
+		reg = __get_csky_regnum(name, flags);
+		break;
+	case EM_SH:
+		reg = _get_dwarf_regnum(sh_regstr_tbl, name);
+		break;
+	case EM_S390:
+		reg = _get_dwarf_regnum(s390_regstr_tbl, name);
+		break;
+	case EM_PPC:
+	case EM_PPC64:
+		reg = _get_dwarf_regnum(powerpc_regstr_tbl, name);
+		break;
+	case EM_RISCV:
+		reg = _get_dwarf_regnum(riscv_regstr_tbl, name);
+		break;
+	case EM_SPARC:
+	case EM_SPARCV9:
+		reg = _get_dwarf_regnum(sparc_regstr_tbl, name);
+		break;
+	case EM_XTENSA:
+		reg = _get_dwarf_regnum(xtensa_regstr_tbl, name);
+		break;
+	case EM_MIPS:
+		reg = _get_dwarf_regnum(mips_regstr_tbl, name);
+		break;
+	case EM_LOONGARCH:
+		reg = _get_dwarf_regnum(loongarch_regstr_tbl, name);
+		break;
+	default:
+		pr_err("ELF MACHINE %x is not supported.\n", machine);
+	}
+	free(regname);
+	return reg;
+
+	#undef _get_dwarf_regnum
+}
+
+static int get_libdw_frame_nregs(unsigned int machine, unsigned int flags __maybe_unused)
+{
+	switch (machine) {
+	case EM_X86_64:
+		return 17;
+	case EM_386:
+		return 9;
+	case EM_ARM:
+		return 16;
+	case EM_AARCH64:
+		return 97;
+	case EM_CSKY:
+		return 38;
+	case EM_S390:
+		return 32;
+	case EM_PPC:
+	case EM_PPC64:
+		return 145;
+	case EM_RISCV:
+		return 66;
+	case EM_SPARC:
+	case EM_SPARCV9:
+		return 103;
+	case EM_LOONGARCH:
+		return 74;
+	case EM_MIPS:
+		return 71;
+	default:
+		return 0;
+	}
+}
+
+int get_dwarf_regnum_for_perf_regnum(int perf_regnum, unsigned int machine,
+				     unsigned int flags, bool only_libdw_supported)
+{
+	int reg;
+
+	switch (machine) {
+	case EM_X86_64:
+		reg = __get_dwarf_regnum_for_perf_regnum_x86_64(perf_regnum);
+		break;
+	case EM_386:
+		reg = __get_dwarf_regnum_for_perf_regnum_i386(perf_regnum);
+		break;
+	case EM_ARM:
+		reg = __get_dwarf_regnum_for_perf_regnum_arm(perf_regnum);
+		break;
+	case EM_AARCH64:
+		reg = __get_dwarf_regnum_for_perf_regnum_arm64(perf_regnum);
+		break;
+	case EM_CSKY:
+		reg = __get_dwarf_regnum_for_perf_regnum_csky(perf_regnum, flags);
+		break;
+	case EM_PPC:
+	case EM_PPC64:
+		reg = __get_dwarf_regnum_for_perf_regnum_powerpc(perf_regnum);
+		break;
+	case EM_RISCV:
+		reg = __get_dwarf_regnum_for_perf_regnum_riscv(perf_regnum);
+		break;
+	case EM_S390:
+		reg = __get_dwarf_regnum_for_perf_regnum_s390(perf_regnum);
+		break;
+	case EM_LOONGARCH:
+		reg = __get_dwarf_regnum_for_perf_regnum_loongarch(perf_regnum);
+		break;
+	case EM_MIPS:
+		reg = __get_dwarf_regnum_for_perf_regnum_mips(perf_regnum);
+		break;
+	default:
+		pr_err("ELF MACHINE %x is not supported.\n", machine);
+		return -ENOENT;
+	}
+	if (reg >= 0 && only_libdw_supported) {
+		int nregs = get_libdw_frame_nregs(machine, flags);
+
+		if (reg >= nregs)
+			reg = -ENOENT;
+	}
+	return reg;
+}