ac: fail shader compilation if libelf is replaced by an incompatible version

UE4Editor has this issue.

This commit prevents hangs (release build) or assertion failures (debug
build). It doesn't fix the editor, but catastrophic scenarios are
prevented.

Cc: 17.1 17.2 <[email protected]>
Reviewed-by: Michel Dänzer <[email protected]>
Reviewed-by: Samuel Pitoiset <[email protected]>
(cherry picked from commit 4630ede1021d49c610de1274dc9d1006b843e46b)

3 files changed, 15 insertions, 4 deletions

diff --git a/src/amd/common/ac_binary.c b/src/amd/common/ac_binary.c
index 618b5cf8b86..1bf52c78328 100644
--- a/src/amd/common/ac_binary.c
+++ b/src/amd/common/ac_binary.c
@@ -109,7 +109,7 @@ static void parse_relocs(Elf *elf, Elf_Data *relocs, Elf_Data *symbols,
 	}
 }
 
-void ac_elf_read(const char *elf_data, unsigned elf_size,
+bool ac_elf_read(const char *elf_data, unsigned elf_size,
 		 struct ac_shader_binary *binary)
 {
 	char *elf_buffer;
@@ -118,6 +118,7 @@ void ac_elf_read(const char *elf_data, unsigned elf_size,
 	Elf_Data *symbols = NULL, *relocs = NULL;
 	size_t section_str_index;
 	unsigned symbol_sh_link = 0;
+	bool success = true;
 
 	/* One of the libelf implementations
 	 * (http://www.mr511.de/software/english.htm) requires calling
@@ -137,7 +138,8 @@ void ac_elf_read(const char *elf_data, unsigned elf_size,
 		GElf_Shdr section_header;
 		if (gelf_getshdr(section, &section_header) != &section_header) {
 			fprintf(stderr, "Failed to read ELF section header\n");
-			return;
+			success = false;
+			break;
 		}
 		name = elf_strptr(elf, section_str_index, section_header.sh_name);
 		if (!strcmp(name, ".text")) {
@@ -148,6 +150,11 @@ void ac_elf_read(const char *elf_data, unsigned elf_size,
 		} else if (!strcmp(name, ".AMDGPU.config")) {
 			section_data = elf_getdata(section, section_data);
 			binary->config_size = section_data->d_size;
+			if (!binary->config_size) {
+				fprintf(stderr, ".AMDGPU.config is empty!\n");
+				success = false;
+				break;
+			}
 			binary->config = MALLOC(binary->config_size * sizeof(unsigned char));
 			memcpy(binary->config, section_data->d_buf, binary->config_size);
 		} else if (!strcmp(name, ".AMDGPU.disasm")) {
@@ -186,6 +193,7 @@ void ac_elf_read(const char *elf_data, unsigned elf_size,
 		binary->global_symbol_count = 1;
 		binary->config_size_per_symbol = binary->config_size;
 	}
+	return success;
 }
 
 const unsigned char *ac_shader_binary_config_start(
diff --git a/src/amd/common/ac_binary.h b/src/amd/common/ac_binary.h
index a784a7220cc..45f554e4fe0 100644
--- a/src/amd/common/ac_binary.h
+++ b/src/amd/common/ac_binary.h
@@ -83,7 +83,7 @@ struct ac_shader_config {
  * Parse the elf binary stored in \p elf_data and create a
  * ac_shader_binary object.
  */
-void ac_elf_read(const char *elf_data, unsigned elf_size,
+bool ac_elf_read(const char *elf_data, unsigned elf_size,
 		 struct ac_shader_binary *binary);
 
 /**
diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c b/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c
index 7218d2da114..8ac931bab37 100644
--- a/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c
+++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c
@@ -243,7 +243,10 @@ unsigned si_llvm_compile(LLVMModuleRef M, struct ac_shader_binary *binary,
 	buffer_size = LLVMGetBufferSize(out_buffer);
 	buffer_data = LLVMGetBufferStart(out_buffer);
 
-	ac_elf_read(buffer_data, buffer_size, binary);
+	if (!ac_elf_read(buffer_data, buffer_size, binary)) {
+		fprintf(stderr, "radeonsi: cannot read an ELF shader binary\n");
+		diag.retval = 1;
+	}
 
 	/* Clean up */
 	LLVMDisposeMemoryBuffer(out_buffer);