diff options
Diffstat (limited to 'scripts/gcc-plugins/stackleak_plugin.c')
| -rw-r--r-- | scripts/gcc-plugins/stackleak_plugin.c | 87 |
1 files changed, 55 insertions, 32 deletions
diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c index e9db7dcb3e5f..e486488c867d 100644 --- a/scripts/gcc-plugins/stackleak_plugin.c +++ b/scripts/gcc-plugins/stackleak_plugin.c @@ -1,7 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2011-2017 by the PaX Team <pageexec@freemail.hu> * Modified by Alexander Popov <alex.popov@linux.com> - * Licensed under the GPL v2 * * Note: the choice of the license means that the compilation process is * NOT 'eligible' as defined by gcc's library exception to the GPL v3, @@ -9,7 +9,7 @@ * any of the gcc libraries * * This gcc plugin is needed for tracking the lowest border of the kernel stack. - * It instruments the kernel code inserting stackleak_track_stack() calls: + * It instruments the kernel code inserting __sanitizer_cov_stack_depth() calls: * - after alloca(); * - for the functions with a stack frame size greater than or equal * to the "track-min-size" plugin parameter. @@ -33,7 +33,7 @@ __visible int plugin_is_GPL_compatible; static int track_frame_size = -1; static bool build_for_x86 = false; -static const char track_function[] = "stackleak_track_stack"; +static const char track_function[] = "__sanitizer_cov_stack_depth"; static bool disable = false; static bool verbose = false; @@ -44,7 +44,7 @@ static bool verbose = false; static GTY(()) tree track_function_decl; static struct plugin_info stackleak_plugin_info = { - .version = "201707101337", + .version = PLUGIN_VERSION, .help = "track-min-size=nn\ttrack stack for functions with a stack frame size >= nn bytes\n" "arch=target_arch\tspecify target build arch\n" "disable\t\tdo not activate the plugin\n" @@ -58,7 +58,7 @@ static void add_stack_tracking_gcall(gimple_stmt_iterator *gsi, bool after) cgraph_node_ptr node; basic_block bb; - /* Insert calling stackleak_track_stack() */ + /* Insert calling __sanitizer_cov_stack_depth() */ stmt = gimple_build_call(track_function_decl, 0); gimple_call = as_a_gcall(stmt); if (after) @@ -120,12 +120,12 @@ static void add_stack_tracking_gasm(gimple_stmt_iterator *gsi, bool after) gcc_assert(build_for_x86); /* - * Insert calling stackleak_track_stack() in asm: - * asm volatile("call stackleak_track_stack" + * Insert calling __sanitizer_cov_stack_depth() in asm: + * asm volatile("call __sanitizer_cov_stack_depth" * :: "r" (current_stack_pointer)) * Use ASM_CALL_CONSTRAINT trick from arch/x86/include/asm/asm.h. * This constraint is taken into account during gcc shrink-wrapping - * optimization. It is needed to be sure that stackleak_track_stack() + * optimization. It is needed to be sure that __sanitizer_cov_stack_depth() * call is inserted after the prologue of the containing function, * when the stack frame is prepared. */ @@ -137,7 +137,7 @@ static void add_stack_tracking_gasm(gimple_stmt_iterator *gsi, bool after) input = build_tree_list(NULL_TREE, build_const_char_string(2, "r")); input = chainon(NULL_TREE, build_tree_list(input, sp_decl)); vec_safe_push(inputs, input); - asm_call = gimple_build_asm_vec("call stackleak_track_stack", + asm_call = gimple_build_asm_vec("call __sanitizer_cov_stack_depth", inputs, NULL, NULL, NULL); gimple_asm_set_volatile(asm_call, true); if (after) @@ -151,11 +151,11 @@ static void add_stack_tracking(gimple_stmt_iterator *gsi, bool after) { /* * The 'no_caller_saved_registers' attribute is used for - * stackleak_track_stack(). If the compiler supports this attribute for - * the target arch, we can add calling stackleak_track_stack() in asm. + * __sanitizer_cov_stack_depth(). If the compiler supports this attribute for + * the target arch, we can add calling __sanitizer_cov_stack_depth() in asm. * That improves performance: we avoid useless operations with the * caller-saved registers in the functions from which we will remove - * stackleak_track_stack() call during the stackleak_cleanup pass. + * __sanitizer_cov_stack_depth() call during the stackleak_cleanup pass. */ if (lookup_attribute_spec(get_identifier("no_caller_saved_registers"))) add_stack_tracking_gasm(gsi, after); @@ -165,7 +165,7 @@ static void add_stack_tracking(gimple_stmt_iterator *gsi, bool after) /* * Work with the GIMPLE representation of the code. Insert the - * stackleak_track_stack() call after alloca() and into the beginning + * __sanitizer_cov_stack_depth() call after alloca() and into the beginning * of the function if it is not instrumented. */ static unsigned int stackleak_instrument_execute(void) @@ -205,7 +205,7 @@ static unsigned int stackleak_instrument_execute(void) DECL_NAME_POINTER(current_function_decl)); } - /* Insert stackleak_track_stack() call after alloca() */ + /* Insert __sanitizer_cov_stack_depth() call after alloca() */ add_stack_tracking(&gsi, true); if (bb == entry_bb) prologue_instrumented = true; @@ -241,7 +241,7 @@ static unsigned int stackleak_instrument_execute(void) return 0; } - /* Insert stackleak_track_stack() call at the function beginning */ + /* Insert __sanitizer_cov_stack_depth() call at the function beginning */ bb = entry_bb; if (!single_pred_p(bb)) { /* gcc_assert(bb_loop_depth(bb) || @@ -270,15 +270,15 @@ static void remove_stack_tracking_gcall(void) rtx_insn *insn, *next; /* - * Find stackleak_track_stack() calls. Loop through the chain of insns, + * Find __sanitizer_cov_stack_depth() calls. Loop through the chain of insns, * which is an RTL representation of the code for a function. * * The example of a matching insn: - * (call_insn 8 4 10 2 (call (mem (symbol_ref ("stackleak_track_stack") - * [flags 0x41] <function_decl 0x7f7cd3302a80 stackleak_track_stack>) - * [0 stackleak_track_stack S1 A8]) (0)) 675 {*call} (expr_list - * (symbol_ref ("stackleak_track_stack") [flags 0x41] <function_decl - * 0x7f7cd3302a80 stackleak_track_stack>) (expr_list (0) (nil))) (nil)) + * (call_insn 8 4 10 2 (call (mem (symbol_ref ("__sanitizer_cov_stack_depth") + * [flags 0x41] <function_decl 0x7f7cd3302a80 __sanitizer_cov_stack_depth>) + * [0 __sanitizer_cov_stack_depth S1 A8]) (0)) 675 {*call} (expr_list + * (symbol_ref ("__sanitizer_cov_stack_depth") [flags 0x41] <function_decl + * 0x7f7cd3302a80 __sanitizer_cov_stack_depth>) (expr_list (0) (nil))) (nil)) */ for (insn = get_insns(); insn; insn = next) { rtx body; @@ -318,7 +318,7 @@ static void remove_stack_tracking_gcall(void) if (SYMBOL_REF_DECL(body) != track_function_decl) continue; - /* Delete the stackleak_track_stack() call */ + /* Delete the __sanitizer_cov_stack_depth() call */ delete_insn_and_edges(insn); #if BUILDING_GCC_VERSION < 8000 if (GET_CODE(next) == NOTE && @@ -340,12 +340,12 @@ static bool remove_stack_tracking_gasm(void) gcc_assert(build_for_x86); /* - * Find stackleak_track_stack() asm calls. Loop through the chain of + * Find __sanitizer_cov_stack_depth() asm calls. Loop through the chain of * insns, which is an RTL representation of the code for a function. * * The example of a matching insn: * (insn 11 5 12 2 (parallel [ (asm_operands/v - * ("call stackleak_track_stack") ("") 0 + * ("call __sanitizer_cov_stack_depth") ("") 0 * [ (reg/v:DI 7 sp [ current_stack_pointer ]) ] * [ (asm_input:DI ("r")) ] []) * (clobber (reg:CC 17 flags)) ]) -1 (nil)) @@ -375,7 +375,7 @@ static bool remove_stack_tracking_gasm(void) continue; if (strcmp(ASM_OPERANDS_TEMPLATE(body), - "call stackleak_track_stack")) { + "call __sanitizer_cov_stack_depth")) { continue; } @@ -389,7 +389,7 @@ static bool remove_stack_tracking_gasm(void) /* * Work with the RTL representation of the code. - * Remove the unneeded stackleak_track_stack() calls from the functions + * Remove the unneeded __sanitizer_cov_stack_depth() calls from the functions * which don't call alloca() and don't have a large enough stack frame size. */ static unsigned int stackleak_cleanup_execute(void) @@ -429,6 +429,23 @@ static unsigned int stackleak_cleanup_execute(void) return 0; } +/* + * STRING_CST may or may not be NUL terminated: + * https://gcc.gnu.org/onlinedocs/gccint/Constant-expressions.html + */ +static inline bool string_equal(tree node, const char *string, int length) +{ + if (TREE_STRING_LENGTH(node) < length) + return false; + if (TREE_STRING_LENGTH(node) > length + 1) + return false; + if (TREE_STRING_LENGTH(node) == length + 1 && + TREE_STRING_POINTER(node)[length] != '\0') + return false; + return !memcmp(TREE_STRING_POINTER(node), string, length); +} +#define STRING_EQUAL(node, str) string_equal(node, str, strlen(str)) + static bool stackleak_gate(void) { tree section; @@ -438,26 +455,32 @@ static bool stackleak_gate(void) if (section && TREE_VALUE(section)) { section = TREE_VALUE(TREE_VALUE(section)); - if (!strncmp(TREE_STRING_POINTER(section), ".init.text", 10)) + if (STRING_EQUAL(section, ".init.text")) + return false; + if (STRING_EQUAL(section, ".devinit.text")) + return false; + if (STRING_EQUAL(section, ".cpuinit.text")) + return false; + if (STRING_EQUAL(section, ".meminit.text")) return false; - if (!strncmp(TREE_STRING_POINTER(section), ".devinit.text", 13)) + if (STRING_EQUAL(section, ".noinstr.text")) return false; - if (!strncmp(TREE_STRING_POINTER(section), ".cpuinit.text", 13)) + if (STRING_EQUAL(section, ".entry.text")) return false; - if (!strncmp(TREE_STRING_POINTER(section), ".meminit.text", 13)) + if (STRING_EQUAL(section, ".head.text")) return false; } return track_frame_size >= 0; } -/* Build the function declaration for stackleak_track_stack() */ +/* Build the function declaration for __sanitizer_cov_stack_depth() */ static void stackleak_start_unit(void *gcc_data __unused, void *user_data __unused) { tree fntype; - /* void stackleak_track_stack(void) */ + /* void __sanitizer_cov_stack_depth(void) */ fntype = build_function_type_list(void_type_node, NULL_TREE); track_function_decl = build_fn_decl(track_function, fntype); DECL_ASSEMBLER_NAME(track_function_decl); /* for LTO */ |