diff options
author | Lance Roy <ldr709@gmail.com> | 2016-12-31 16:33:50 -0800 |
---|---|---|
committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-25 12:54:22 -0800 |
commit | 418b2977b34378f67c46930c72a776f94e7bf903 (patch) | |
tree | 2f3f41dd02a80f237bda867211e4bb852c0c9a08 | |
parent | d85b62f18d543c663cbdd6061054efeb9e66cee7 (diff) | |
download | linux-418b2977b34378f67c46930c72a776f94e7bf903.tar.bz2 |
rcutorture: Add CBMC-based formal verification for SRCU
This commit creates a formal/srcu-cbmc directory containing scripts that
pull SRCU in from the source code, filter it to remove things that CBMC
cannot handle, and run a series of verifications on it. This has a number
of shortcomings:
1. It does not yet hook into the upper-level self-test Makefiles.
2. It tests only a single scenario, store buffering.
3. There is no gcc-based syntax-error prefiltering.
Nevertheless, it does fully verify a piece of SRCU under a moderately
weak memory model (PSO).
Signed-off-by: Lance Roy <ldr709@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
40 files changed, 1582 insertions, 0 deletions
diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/.gitignore b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/.gitignore new file mode 100644 index 000000000000..712a3d41a325 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/.gitignore @@ -0,0 +1 @@ +srcu.c diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/Makefile b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/Makefile new file mode 100644 index 000000000000..16b01559fa55 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/Makefile @@ -0,0 +1,16 @@ +all: srcu.c store_buffering + +LINUX_SOURCE = ../../../../../.. + +modified_srcu_input = $(LINUX_SOURCE)/include/linux/srcu.h \ + $(LINUX_SOURCE)/kernel/rcu/srcu.c + +modified_srcu_output = include/linux/srcu.h srcu.c + +include/linux/srcu.h: srcu.c + +srcu.c: modify_srcu.awk Makefile $(modified_srcu_input) + awk -f modify_srcu.awk $(modified_srcu_input) $(modified_srcu_output) + +store_buffering: + @cd tests/store_buffering; make diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/delay.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/delay.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/delay.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/export.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/export.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/export.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/mutex.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/mutex.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/mutex.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/percpu.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/percpu.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/percpu.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/preempt.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/preempt.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/preempt.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/rcupdate.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/rcupdate.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/rcupdate.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/sched.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/sched.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/sched.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/smp.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/smp.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/smp.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/workqueue.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/workqueue.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/linux/workqueue.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/uapi/linux/types.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/uapi/linux/types.h new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/empty_includes/uapi/linux/types.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/.gitignore b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/.gitignore new file mode 100644 index 000000000000..1d016e66980a --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/.gitignore @@ -0,0 +1 @@ +srcu.h diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/kconfig.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/kconfig.h new file mode 100644 index 000000000000..f2860dd1b407 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/kconfig.h @@ -0,0 +1 @@ +#include <LINUX_SOURCE/linux/kconfig.h> diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/types.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/types.h new file mode 100644 index 000000000000..4a3d538fef12 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/types.h @@ -0,0 +1,155 @@ +/* + * This header has been modifies to remove definitions of types that + * are defined in standard userspace headers or are problematic for some + * other reason. + */ + +#ifndef _LINUX_TYPES_H +#define _LINUX_TYPES_H + +#define __EXPORTED_HEADERS__ +#include <uapi/linux/types.h> + +#ifndef __ASSEMBLY__ + +#define DECLARE_BITMAP(name, bits) \ + unsigned long name[BITS_TO_LONGS(bits)] + +typedef __u32 __kernel_dev_t; + +/* bsd */ +typedef unsigned char u_char; +typedef unsigned short u_short; +typedef unsigned int u_int; +typedef unsigned long u_long; + +/* sysv */ +typedef unsigned char unchar; +typedef unsigned short ushort; +typedef unsigned int uint; +typedef unsigned long ulong; + +#ifndef __BIT_TYPES_DEFINED__ +#define __BIT_TYPES_DEFINED__ + +typedef __u8 u_int8_t; +typedef __s8 int8_t; +typedef __u16 u_int16_t; +typedef __s16 int16_t; +typedef __u32 u_int32_t; +typedef __s32 int32_t; + +#endif /* !(__BIT_TYPES_DEFINED__) */ + +typedef __u8 uint8_t; +typedef __u16 uint16_t; +typedef __u32 uint32_t; + +/* this is a special 64bit data type that is 8-byte aligned */ +#define aligned_u64 __u64 __attribute__((aligned(8))) +#define aligned_be64 __be64 __attribute__((aligned(8))) +#define aligned_le64 __le64 __attribute__((aligned(8))) + +/** + * The type used for indexing onto a disc or disc partition. + * + * Linux always considers sectors to be 512 bytes long independently + * of the devices real block size. + * + * blkcnt_t is the type of the inode's block count. + */ +#ifdef CONFIG_LBDAF +typedef u64 sector_t; +#else +typedef unsigned long sector_t; +#endif + +/* + * The type of an index into the pagecache. + */ +#define pgoff_t unsigned long + +/* + * A dma_addr_t can hold any valid DMA address, i.e., any address returned + * by the DMA API. + * + * If the DMA API only uses 32-bit addresses, dma_addr_t need only be 32 + * bits wide. Bus addresses, e.g., PCI BARs, may be wider than 32 bits, + * but drivers do memory-mapped I/O to ioremapped kernel virtual addresses, + * so they don't care about the size of the actual bus addresses. + */ +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT +typedef u64 dma_addr_t; +#else +typedef u32 dma_addr_t; +#endif + +#ifdef CONFIG_PHYS_ADDR_T_64BIT +typedef u64 phys_addr_t; +#else +typedef u32 phys_addr_t; +#endif + +typedef phys_addr_t resource_size_t; + +/* + * This type is the placeholder for a hardware interrupt number. It has to be + * big enough to enclose whatever representation is used by a given platform. + */ +typedef unsigned long irq_hw_number_t; + +typedef struct { + int counter; +} atomic_t; + +#ifdef CONFIG_64BIT +typedef struct { + long counter; +} atomic64_t; +#endif + +struct list_head { + struct list_head *next, *prev; +}; + +struct hlist_head { + struct hlist_node *first; +}; + +struct hlist_node { + struct hlist_node *next, **pprev; +}; + +/** + * struct callback_head - callback structure for use with RCU and task_work + * @next: next update requests in a list + * @func: actual update function to call after the grace period. + * + * The struct is aligned to size of pointer. On most architectures it happens + * naturally due ABI requirements, but some architectures (like CRIS) have + * weird ABI and we need to ask it explicitly. + * + * The alignment is required to guarantee that bits 0 and 1 of @next will be + * clear under normal conditions -- as long as we use call_rcu(), + * call_rcu_bh(), call_rcu_sched(), or call_srcu() to queue callback. + * + * This guarantee is important for few reasons: + * - future call_rcu_lazy() will make use of lower bits in the pointer; + * - the structure shares storage spacer in struct page with @compound_head, + * which encode PageTail() in bit 0. The guarantee is needed to avoid + * false-positive PageTail(). + */ +struct callback_head { + struct callback_head *next; + void (*func)(struct callback_head *head); +} __attribute__((aligned(sizeof(void *)))); +#define rcu_head callback_head + +typedef void (*rcu_callback_t)(struct rcu_head *head); +typedef void (*call_rcu_func_t)(struct rcu_head *head, rcu_callback_t func); + +/* clocksource cycle base type */ +typedef u64 cycle_t; + +#endif /* __ASSEMBLY__ */ +#endif /* _LINUX_TYPES_H */ diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/modify_srcu.awk b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/modify_srcu.awk new file mode 100755 index 000000000000..8ff89043d0a9 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/modify_srcu.awk @@ -0,0 +1,375 @@ +#!/bin/awk -f + +# Modify SRCU for formal verification. The first argument should be srcu.h and +# the second should be srcu.c. Outputs modified srcu.h and srcu.c into the +# current directory. + +BEGIN { + if (ARGC != 5) { + print "Usange: input.h input.c output.h output.c" > "/dev/stderr"; + exit 1; + } + h_output = ARGV[3]; + c_output = ARGV[4]; + ARGC = 3; + + # Tokenize using FS and not RS as FS supports regular expressions. Each + # record is one line of source, except that backslashed lines are + # combined. Comments are treated as field separators, as are quotes. + quote_regexp="\"([^\\\\\"]|\\\\.)*\""; + comment_regexp="\\/\\*([^*]|\\*+[^*/])*\\*\\/|\\/\\/.*(\n|$)"; + FS="([ \\\\\t\n\v\f;,.=(){}+*/<>&|^-]|\\[|\\]|" comment_regexp "|" quote_regexp ")+"; + + inside_srcu_struct = 0; + inside_srcu_init_def = 0; + srcu_init_param_name = ""; + in_macro = 0; + brace_nesting = 0; + paren_nesting = 0; + + # Allow the manipulation of the last field separator after has been + # seen. + last_fs = ""; + # Whether the last field separator was intended to be output. + last_fs_print = 0; + + # rcu_batches stores the initialization for each instance of struct + # rcu_batch + + in_comment = 0; + + outputfile = ""; +} + +{ + prev_outputfile = outputfile; + if (FILENAME ~ /\.h$/) { + outputfile = h_output; + if (FNR != NR) { + print "Incorrect file order" > "/dev/stderr"; + exit 1; + } + } + else + outputfile = c_output; + + if (prev_outputfile && outputfile != prev_outputfile) { + new_outputfile = outputfile; + outputfile = prev_outputfile; + update_fieldsep("", 0); + outputfile = new_outputfile; + } +} + +# Combine the next line into $0. +function combine_line() { + ret = getline next_line; + if (ret == 0) { + # Don't allow two consecutive getlines at the end of the file + if (eof_found) { + print "Error: expected more input." > "/dev/stderr"; + exit 1; + } else { + eof_found = 1; + } + } else if (ret == -1) { + print "Error reading next line of file" FILENAME > "/dev/stderr"; + exit 1; + } + $0 = $0 "\n" next_line; +} + +# Combine backslashed lines and multiline comments. +function combine_backslashes() { + while (/\\$|\/\*([^*]|\*+[^*\/])*\**$/) { + combine_line(); + } +} + +function read_line() { + combine_line(); + combine_backslashes(); +} + +# Print out field separators and update variables that depend on them. Only +# print if p is true. Call with sep="" and p=0 to print out the last field +# separator. +function update_fieldsep(sep, p) { + # Count braces + sep_tmp = sep; + gsub(quote_regexp "|" comment_regexp, "", sep_tmp); + while (1) + { + if (sub("[^{}()]*\\{", "", sep_tmp)) { + brace_nesting++; + continue; + } + if (sub("[^{}()]*\\}", "", sep_tmp)) { + brace_nesting--; + if (brace_nesting < 0) { + print "Unbalanced braces!" > "/dev/stderr"; + exit 1; + } + continue; + } + if (sub("[^{}()]*\\(", "", sep_tmp)) { + paren_nesting++; + continue; + } + if (sub("[^{}()]*\\)", "", sep_tmp)) { + paren_nesting--; + if (paren_nesting < 0) { + print "Unbalanced parenthesis!" > "/dev/stderr"; + exit 1; + } + continue; + } + + break; + } + + if (last_fs_print) + printf("%s", last_fs) > outputfile; + last_fs = sep; + last_fs_print = p; +} + +# Shifts the fields down by n positions. Calls next if there are no more. If p +# is true then print out field separators. +function shift_fields(n, p) { + do { + if (match($0, FS) > 0) { + update_fieldsep(substr($0, RSTART, RLENGTH), p); + if (RSTART + RLENGTH <= length()) + $0 = substr($0, RSTART + RLENGTH); + else + $0 = ""; + } else { + update_fieldsep("", 0); + print "" > outputfile; + next; + } + } while (--n > 0); +} + +# Shifts and prints the first n fields. +function print_fields(n) { + do { + update_fieldsep("", 0); + printf("%s", $1) > outputfile; + shift_fields(1, 1); + } while (--n > 0); +} + +{ + combine_backslashes(); +} + +# Print leading FS +{ + if (match($0, "^(" FS ")+") > 0) { + update_fieldsep(substr($0, RSTART, RLENGTH), 1); + if (RSTART + RLENGTH <= length()) + $0 = substr($0, RSTART + RLENGTH); + else + $0 = ""; + } +} + +# Parse the line. +{ + while (NF > 0) { + if ($1 == "struct" && NF < 3) { + read_line(); + continue; + } + + if (FILENAME ~ /\.h$/ && !inside_srcu_struct && + brace_nesting == 0 && paren_nesting == 0 && + $1 == "struct" && $2 == "srcu_struct" && + $0 ~ "^struct(" FS ")+srcu_struct(" FS ")+\\{") { + inside_srcu_struct = 1; + print_fields(2); + continue; + } + if (inside_srcu_struct && brace_nesting == 0 && + paren_nesting == 0) { + inside_srcu_struct = 0; + update_fieldsep("", 0); + for (name in rcu_batches) + print "extern struct rcu_batch " name ";" > outputfile; + } + + if (inside_srcu_struct && $1 == "struct" && $2 == "rcu_batch") { + # Move rcu_batches outside of the struct. + rcu_batches[$3] = ""; + shift_fields(3, 1); + sub(/;[[:space:]]*$/, "", last_fs); + continue; + } + + if (FILENAME ~ /\.h$/ && !inside_srcu_init_def && + $1 == "#define" && $2 == "__SRCU_STRUCT_INIT") { + inside_srcu_init_def = 1; + srcu_init_param_name = $3; + in_macro = 1; + print_fields(3); + continue; + } + if (inside_srcu_init_def && brace_nesting == 0 && + paren_nesting == 0) { + inside_srcu_init_def = 0; + in_macro = 0; + continue; + } + + if (inside_srcu_init_def && brace_nesting == 1 && + paren_nesting == 0 && last_fs ~ /\.[[:space:]]*$/ && + $1 ~ /^[[:alnum:]_]+$/) { + name = $1; + if (name in rcu_batches) { + # Remove the dot. + sub(/\.[[:space:]]*$/, "", last_fs); + + old_record = $0; + do + shift_fields(1, 0); + while (last_fs !~ /,/ || paren_nesting > 0); + end_loc = length(old_record) - length($0); + end_loc += index(last_fs, ",") - length(last_fs); + + last_fs = substr(last_fs, index(last_fs, ",") + 1); + last_fs_print = 1; + + match(old_record, "^"name"("FS")+="); + start_loc = RSTART + RLENGTH; + + len = end_loc - start_loc; + initializer = substr(old_record, start_loc, len); + gsub(srcu_init_param_name "\\.", "", initializer); + rcu_batches[name] = initializer; + continue; + } + } + + # Don't include a nonexistent file + if (!in_macro && $1 == "#include" && /^#include[[:space:]]+"rcu\.h"/) { + update_fieldsep("", 0); + next; + } + + # Ignore most preprocessor stuff. + if (!in_macro && $1 ~ /#/) { + break; + } + + if (brace_nesting > 0 && $1 ~ "^[[:alnum:]_]+$" && NF < 2) { + read_line(); + continue; + } + if (brace_nesting > 0 && + $0 ~ "^[[:alnum:]_]+[[:space:]]*(\\.|->)[[:space:]]*[[:alnum:]_]+" && + $2 in rcu_batches) { + # Make uses of rcu_batches global. Somewhat unreliable. + shift_fields(1, 0); + print_fields(1); + continue; + } + + if ($1 == "static" && NF < 3) { + read_line(); + continue; + } + if ($1 == "static" && ($2 == "bool" && $3 == "try_check_zero" || + $2 == "void" && $3 == "srcu_flip")) { + shift_fields(1, 1); + print_fields(2); + continue; + } + + # Distinguish between read-side and write-side memory barriers. + if ($1 == "smp_mb" && NF < 2) { + read_line(); + continue; + } + if (match($0, /^smp_mb[[:space:]();\/*]*[[:alnum:]]/)) { + barrier_letter = substr($0, RLENGTH, 1); + if (barrier_letter ~ /A|D/) + new_barrier_name = "sync_smp_mb"; + else if (barrier_letter ~ /B|C/) + new_barrier_name = "rs_smp_mb"; + else { + print "Unrecognized memory barrier." > "/dev/null"; + exit 1; + } + + shift_fields(1, 1); + printf("%s", new_barrier_name) > outputfile; + continue; + } + + # Skip definition of rcu_synchronize, since it is already + # defined in misc.h. Only present in old versions of srcu. + if (brace_nesting == 0 && paren_nesting == 0 && + $1 == "struct" && $2 == "rcu_synchronize" && + $0 ~ "^struct(" FS ")+rcu_synchronize(" FS ")+\\{") { + shift_fields(2, 0); + while (brace_nesting) { + if (NF < 2) + read_line(); + shift_fields(1, 0); + } + } + + # Skip definition of wakeme_after_rcu for the same reason + if (brace_nesting == 0 && $1 == "static" && $2 == "void" && + $3 == "wakeme_after_rcu") { + while (NF < 5) + read_line(); + shift_fields(3, 0); + do { + while (NF < 3) + read_line(); + shift_fields(1, 0); + } while (paren_nesting || brace_nesting); + } + + if ($1 ~ /^(unsigned|long)$/ && NF < 3) { + read_line(); + continue; + } + + # Give srcu_batches_completed the correct type for old SRCU. + if (brace_nesting == 0 && $1 == "long" && + $2 == "srcu_batches_completed") { + update_fieldsep("", 0); + printf("unsigned ") > outputfile; + print_fields(2); + continue; + } + if (brace_nesting == 0 && $1 == "unsigned" && $2 == "long" && + $3 == "srcu_batches_completed") { + print_fields(3); + continue; + } + + # Just print out the input code by default. + print_fields(1); + } + update_fieldsep("", 0); + print > outputfile; + next; +} + +END { + update_fieldsep("", 0); + + if (brace_nesting != 0) { + print "Unbalanced braces!" > "/dev/stderr"; + exit 1; + } + + # Define the rcu_batches + for (name in rcu_batches) + print "struct rcu_batch " name " = " rcu_batches[name] ";" > c_output; +} diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/assume.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/assume.h new file mode 100644 index 000000000000..a64955447995 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/assume.h @@ -0,0 +1,16 @@ +#ifndef ASSUME_H +#define ASSUME_H + +/* Provide an assumption macro that can be disabled for gcc. */ +#ifdef RUN +#define assume(x) \ + do { \ + /* Evaluate x to suppress warnings. */ \ + (void) (x); \ + } while (0) + +#else +#define assume(x) __CPROVER_assume(x) +#endif + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h new file mode 100644 index 000000000000..6687acc08e6d --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h @@ -0,0 +1,41 @@ +#ifndef BARRIERS_H +#define BARRIERS_H + +#define barrier() __asm__ __volatile__("" : : : "memory") + +#ifdef RUN +#define smp_mb() __sync_synchronize() +#define smp_mb__after_unlock_lock() __sync_synchronize() +#else +/* + * Copied from CBMC's implementation of __sync_synchronize(), which + * seems to be disabled by default. + */ +#define smp_mb() __CPROVER_fence("WWfence", "RRfence", "RWfence", "WRfence", \ + "WWcumul", "RRcumul", "RWcumul", "WRcumul") +#define smp_mb__after_unlock_lock() __CPROVER_fence("WWfence", "RRfence", "RWfence", "WRfence", \ + "WWcumul", "RRcumul", "RWcumul", "WRcumul") +#endif + +/* + * Allow memory barriers to be disabled in either the read or write side + * of SRCU individually. + */ + +#ifndef NO_SYNC_SMP_MB +#define sync_smp_mb() smp_mb() +#else +#define sync_smp_mb() do {} while (0) +#endif + +#ifndef NO_READ_SIDE_SMP_MB +#define rs_smp_mb() smp_mb() +#else +#define rs_smp_mb() do {} while (0) +#endif + +#define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x)) +#define READ_ONCE(x) ACCESS_ONCE(x) +#define WRITE_ONCE(x, val) (ACCESS_ONCE(x) = (val)) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/bug_on.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/bug_on.h new file mode 100644 index 000000000000..2a80e91f78e7 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/bug_on.h @@ -0,0 +1,13 @@ +#ifndef BUG_ON_H +#define BUG_ON_H + +#include <assert.h> + +#define BUG() assert(0) +#define BUG_ON(x) assert(!(x)) + +/* Does it make sense to treat warnings as errors? */ +#define WARN() BUG() +#define WARN_ON(x) (BUG_ON(x), false) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/combined_source.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/combined_source.c new file mode 100644 index 000000000000..29eb5d2697ed --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/combined_source.c @@ -0,0 +1,13 @@ +#include <config.h> + +/* Include all source files. */ + +#include "include_srcu.c" + +#include "preempt.c" +#include "misc.c" + +/* Used by test.c files */ +#include <pthread.h> +#include <stdlib.h> +#include <linux/srcu.h> diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/config.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/config.h new file mode 100644 index 000000000000..a60038aeea7a --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/config.h @@ -0,0 +1,27 @@ +/* "Cheater" definitions based on restricted Kconfig choices. */ + +#undef CONFIG_TINY_RCU +#undef __CHECKER__ +#undef CONFIG_DEBUG_LOCK_ALLOC +#undef CONFIG_DEBUG_OBJECTS_RCU_HEAD +#undef CONFIG_HOTPLUG_CPU +#undef CONFIG_MODULES +#undef CONFIG_NO_HZ_FULL_SYSIDLE +#undef CONFIG_PREEMPT_COUNT +#undef CONFIG_PREEMPT_RCU +#undef CONFIG_PROVE_RCU +#undef CONFIG_RCU_NOCB_CPU +#undef CONFIG_RCU_NOCB_CPU_ALL +#undef CONFIG_RCU_STALL_COMMON +#undef CONFIG_RCU_TRACE +#undef CONFIG_RCU_USER_QS +#undef CONFIG_TASKS_RCU +#define CONFIG_TREE_RCU + +#define CONFIG_GENERIC_ATOMIC64 + +#if NR_CPUS > 1 +#define CONFIG_SMP +#else +#undef CONFIG_SMP +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/include_srcu.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/include_srcu.c new file mode 100644 index 000000000000..5ec582a53018 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/include_srcu.c @@ -0,0 +1,31 @@ +#include <config.h> + +#include <assert.h> +#include <errno.h> +#include <inttypes.h> +#include <pthread.h> +#include <stddef.h> +#include <string.h> +#include <sys/types.h> + +#include "int_typedefs.h" + +#include "barriers.h" +#include "bug_on.h" +#include "locks.h" +#include "misc.h" +#include "preempt.h" +#include "percpu.h" +#include "workqueues.h" + +#ifdef USE_SIMPLE_SYNC_SRCU +#define synchronize_srcu(sp) synchronize_srcu_original(sp) +#endif + +#include <srcu.c> + +#ifdef USE_SIMPLE_SYNC_SRCU +#undef synchronize_srcu + +#include "simple_sync_srcu.c" +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/int_typedefs.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/int_typedefs.h new file mode 100644 index 000000000000..3aad63917858 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/int_typedefs.h @@ -0,0 +1,33 @@ +#ifndef INT_TYPEDEFS_H +#define INT_TYPEDEFS_H + +#include <inttypes.h> + +typedef int8_t s8; +typedef uint8_t u8; +typedef int16_t s16; +typedef uint16_t u16; +typedef int32_t s32; +typedef uint32_t u32; +typedef int64_t s64; +typedef uint64_t u64; + +typedef int8_t __s8; +typedef uint8_t __u8; +typedef int16_t __s16; +typedef uint16_t __u16; +typedef int32_t __s32; +typedef uint32_t __u32; +typedef int64_t __s64; +typedef uint64_t __u64; + +#define S8_C(x) INT8_C(x) +#define U8_C(x) UINT8_C(x) +#define S16_C(x) INT16_C(x) +#define U16_C(x) UINT16_C(x) +#define S32_C(x) INT32_C(x) +#define U32_C(x) UINT32_C(x) +#define S64_C(x) INT64_C(x) +#define U64_C(x) UINT64_C(x) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h new file mode 100644 index 000000000000..356004665576 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h @@ -0,0 +1,220 @@ +#ifndef LOCKS_H +#define LOCKS_H + +#include <limits.h> +#include <pthread.h> +#include <stdbool.h> + +#include "assume.h" +#include "bug_on.h" +#include "preempt.h" + +int nondet_int(void); + +#define __acquire(x) +#define __acquires(x) +#define __release(x) +#define __releases(x) + +/* Only use one lock mechanism. Select which one. */ +#ifdef PTHREAD_LOCK +struct lock_impl { + pthread_mutex_t mutex; +}; + +static inline void lock_impl_lock(struct lock_impl *lock) +{ + BUG_ON(pthread_mutex_lock(&lock->mutex)); +} + +static inline void lock_impl_unlock(struct lock_impl *lock) +{ + BUG_ON(pthread_mutex_unlock(&lock->mutex)); +} + +static inline bool lock_impl_trylock(struct lock_impl *lock) +{ + int err = pthread_mutex_trylock(&lock->mutex); + + if (!err) + return true; + else if (err == EBUSY) + return false; + BUG(); +} + +static inline void lock_impl_init(struct lock_impl *lock) +{ + pthread_mutex_init(&lock->mutex, NULL); +} + +#define LOCK_IMPL_INITIALIZER {.mutex = PTHREAD_MUTEX_INITIALIZER} + +#else /* !defined(PTHREAD_LOCK) */ +/* Spinlock that assumes that it always gets the lock immediately. */ + +struct lock_impl { + bool locked; +}; + +static inline bool lock_impl_trylock(struct lock_impl *lock) +{ +#ifdef RUN + /* TODO: Should this be a test and set? */ + return __sync_bool_compare_and_swap(&lock->locked, false, true); +#else + __CPROVER_atomic_begin(); + bool old_locked = lock->locked; + lock->locked = true; + __CPROVER_atomic_end(); + + /* Minimal barrier to prevent accesses leaking out of lock. */ + __CPROVER_fence("RRfence", "RWfence"); + + return !old_locked; +#endif +} + +static inline void lock_impl_lock(struct lock_impl *lock) +{ + /* + * CBMC doesn't support busy waiting, so just assume that the + * lock is available. + */ + assume(lock_impl_trylock(lock)); + + /* + * If the lock was already held by this thread then the assumption + * is unsatisfiable (deadlock). + */ +} + +static inline void lock_impl_unlock(struct lock_impl *lock) +{ +#ifdef RUN + BUG_ON(!__sync_bool_compare_and_swap(&lock->locked, true, false)); +#else + /* Minimal barrier to prevent accesses leaking out of lock. */ + __CPROVER_fence("RWfence", "WWfence"); + + __CPROVER_atomic_begin(); + bool old_locked = lock->locked; + lock->locked = false; + __CPROVER_atomic_end(); + + BUG_ON(!old_locked); +#endif +} + +static inline void lock_impl_init(struct lock_impl *lock) +{ + lock->locked = false; +} + +#define LOCK_IMPL_INITIALIZER {.locked = false} + +#endif /* !defined(PTHREAD_LOCK) */ + +/* + * Implement spinlocks using the lock mechanism. Wrap the lock to prevent mixing + * locks of different types. + */ +typedef struct { + struct lock_impl internal_lock; +} spinlock_t; + +#define SPIN_LOCK_UNLOCKED {.internal_lock = LOCK_IMPL_INITIALIZER} +#define __SPIN_LOCK_UNLOCKED(x) SPIN_LOCK_UNLOCKED +#define DEFINE_SPINLOCK(x) spinlock_t x = SPIN_LOCK_UNLOCKED + +static inline void spin_lock_init(spinlock_t *lock) +{ + lock_impl_init(&lock->internal_lock); +} + +static inline void spin_lock(spinlock_t *lock) +{ + /* + * Spin locks also need to be removed in order to eliminate all + * memory barriers. They are only used by the write side anyway. + */ +#ifndef NO_SYNC_SMP_MB + preempt_disable(); + lock_impl_lock(&lock->internal_lock); +#endif +} + +static inline void spin_unlock(spinlock_t *lock) +{ +#ifndef NO_SYNC_SMP_MB + lock_impl_unlock(&lock->internal_lock); + preempt_enable(); +#endif +} + +/* Don't bother with interrupts */ +#define spin_lock_irq(lock) spin_lock(lock) +#define spin_unlock_irq(lock) spin_unlock(lock) +#define spin_lock_irqsave(lock, flags) spin_lock(lock) +#define spin_unlock_irqrestore(lock, flags) spin_unlock(lock) + +/* + * This is supposed to return an int, but I think that a bool should work as + * well. + */ +static inline bool spin_trylock(spinlock_t *lock) +{ +#ifndef NO_SYNC_SMP_MB + preempt_disable(); + return lock_impl_trylock(&lock->internal_lock); +#else + return true; +#endif +} + +struct completion { + /* Hopefuly this won't overflow. */ + unsigned int count; +}; + +#define COMPLETION_INITIALIZER(x) {.count = 0} +#define DECLARE_COMPLETION(x) struct completion x = COMPLETION_INITIALIZER(x) +#define DECLARE_COMPLETION_ONSTACK(x) DECLARE_COMPLETION(x) + +static inline void init_completion(struct completion *c) +{ + c->count = 0; +} + +static inline void wait_for_completion(struct completion *c) +{ + unsigned int prev_count = __sync_fetch_and_sub(&c->count, 1); + + assume(prev_count); +} + +static inline void complete(struct completion *c) +{ + unsigned int prev_count = __sync_fetch_and_add(&c->count, 1); + + BUG_ON(prev_count == UINT_MAX); +} + +/* This function probably isn't very useful for CBMC. */ +static inline bool try_wait_for_completion(struct completion *c) +{ + BUG(); +} + +static inline bool completion_done(struct completion *c) +{ + return c->count; +} + +/* TODO: Implement complete_all */ +static inline void complete_all(struct completion *c) +{ + BUG(); +} + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.c new file mode 100644 index 000000000000..ca892e3b2351 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.c @@ -0,0 +1,11 @@ +#include <config.h> + +#include "misc.h" +#include "bug_on.h" + +struct rcu_head; + +void wakeme_after_rcu(struct rcu_head *head) +{ + BUG(); +} diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.h new file mode 100644 index 000000000000..aca50030f954 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.h @@ -0,0 +1,58 @@ +#ifndef MISC_H +#define MISC_H + +#include "assume.h" +#include "int_typedefs.h" +#include "locks.h" + +#include <linux/types.h> + +/* Probably won't need to deal with bottom halves. */ +static inline void local_bh_disable(void) {} +static inline void local_bh_enable(void) {} + +#define MODULE_ALIAS(X) +#define module_param(...) +#define EXPORT_SYMBOL_GPL(x) + +#define container_of(ptr, type, member) ({ \ + const typeof(((type *)0)->member) *__mptr = (ptr); \ + (type *)((char *)__mptr - offsetof(type, member)); \ +}) + +#ifndef USE_SIMPLE_SYNC_SRCU +/* Abuse udelay to make sure that busy loops terminate. */ +#define udelay(x) assume(0) + +#else + +/* The simple custom synchronize_srcu is ok with try_check_zero failing. */ +#define udelay(x) do { } while (0) +#endif + +#define trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ + do { } while (0) + +#define notrace + +/* Avoid including rcupdate.h */ +struct rcu_synchronize { + struct rcu_head head; + struct completion completion; +}; + +void wakeme_after_rcu(struct rcu_head *head); + +#define rcu_lock_acquire(a) do { } while (0) +#define rcu_lock_release(a) do { } while (0) +#define rcu_lockdep_assert(c, s) do { } while (0) +#define RCU_LOCKDEP_WARN(c, s) do { } while (0) + +/* Let CBMC non-deterministically choose switch between normal and expedited. */ +bool rcu_gp_is_normal(void); +bool rcu_gp_is_expedited(void); + +/* Do the same for old versions of rcu. */ +#define rcu_expedited (rcu_gp_is_expedited()) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/percpu.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/percpu.h new file mode 100644 index 000000000000..3de5a49de49b --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/percpu.h @@ -0,0 +1,92 @@ +#ifndef PERCPU_H +#define PERCPU_H + +#include <stddef.h> +#include "bug_on.h" +#include "preempt.h" + +#define __percpu + +/* Maximum size of any percpu data. */ +#define PERCPU_OFFSET (4 * sizeof(long)) + +/* Ignore alignment, as CBMC doesn't care about false sharing. */ +#define alloc_percpu(type) __alloc_percpu(sizeof(type), 1) + +static inline void *__alloc_percpu(size_t size, size_t align) +{ + BUG(); + return NULL; +} + +static inline void free_percpu(void *ptr) +{ + BUG(); +} + +#define per_cpu_ptr(ptr, cpu) \ + ((typeof(ptr)) ((char *) (ptr) + PERCPU_OFFSET * cpu)) + +#define __this_cpu_inc(pcp) __this_cpu_add(pcp, 1) +#define __this_cpu_dec(pcp) __this_cpu_sub(pcp, 1) +#define __this_cpu_sub(pcp, n) __this_cpu_add(pcp, -(typeof(pcp)) (n)) + +#define this_cpu_inc(pcp) this_cpu_add(pcp, 1) +#define this_cpu_dec(pcp) this_cpu_sub(pcp, 1) +#define this_cpu_sub(pcp, n) this_cpu_add(pcp, -(typeof(pcp)) (n)) + +/* Make CBMC use atomics to work around bug. */ +#ifdef RUN +#define THIS_CPU_ADD_HELPER(ptr, x) (*(ptr) += (x)) +#else +/* + * Split the atomic into a read and a write so that it has the least + * possible ordering. + */ +#define THIS_CPU_ADD_HELPER(ptr, x) \ + do { \ + typeof(ptr) this_cpu_add_helper_ptr = (ptr); \ + typeof(ptr) this_cpu_add_helper_x = (x); \ + typeof(*ptr) this_cpu_add_helper_temp; \ + __CPROVER_atomic_begin(); \ + this_cpu_add_helper_temp = *(this_cpu_add_helper_ptr); \ + __CPROVER_atomic_end(); \ + this_cpu_add_helper_temp += this_cpu_add_helper_x; \ + __CPROVER_atomic_begin(); \ + *(this_cpu_add_helper_ptr) = this_cpu_add_helper_temp; \ + __CPROVER_atomic_end(); \ + } while (0) +#endif + +/* + * For some reason CBMC needs an atomic operation even though this is percpu + * data. + */ +#define __this_cpu_add(pcp, n) \ + do { \ + BUG_ON(preemptible()); \ + THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), thread_cpu_id), \ + (typeof(pcp)) (n)); \ + } while (0) + +#define this_cpu_add(pcp, n) \ + do { \ + int this_cpu_add_impl_cpu = get_cpu(); \ + THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), this_cpu_add_impl_cpu), \ + (typeof(pcp)) (n)); \ + put_cpu(); \ + } while (0) + +/* + * This will cause a compiler warning because of the cast from char[][] to + * type*. This will cause a compile time error if type is too big. + */ +#define DEFINE_PER_CPU(type, name) \ + char name[NR_CPUS][PERCPU_OFFSET]; \ + typedef char percpu_too_big_##name \ + [sizeof(type) > PERCPU_OFFSET ? -1 : 1] + +#define for_each_possible_cpu(cpu) \ + for ((cpu) = 0; (cpu) < NR_CPUS; ++(cpu)) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.c new file mode 100644 index 000000000000..4f1b068e9b7a --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.c @@ -0,0 +1,78 @@ +#include <config.h> + +#include "preempt.h" + +#include "assume.h" +#include "locks.h" + +/* Support NR_CPUS of at most 64 */ +#define CPU_PREEMPTION_LOCKS_INIT0 LOCK_IMPL_INITIALIZER +#define CPU_PREEMPTION_LOCKS_INIT1 \ + CPU_PREEMPTION_LOCKS_INIT0, CPU_PREEMPTION_LOCKS_INIT0 +#define CPU_PREEMPTION_LOCKS_INIT2 \ + CPU_PREEMPTION_LOCKS_INIT1, CPU_PREEMPTION_LOCKS_INIT1 +#define CPU_PREEMPTION_LOCKS_INIT3 \ + CPU_PREEMPTION_LOCKS_INIT2, CPU_PREEMPTION_LOCKS_INIT2 +#define CPU_PREEMPTION_LOCKS_INIT4 \ + CPU_PREEMPTION_LOCKS_INIT3, CPU_PREEMPTION_LOCKS_INIT3 +#define CPU_PREEMPTION_LOCKS_INIT5 \ + CPU_PREEMPTION_LOCKS_INIT4, CPU_PREEMPTION_LOCKS_INIT4 + +/* + * Simulate disabling preemption by locking a particular cpu. NR_CPUS + * should be the actual number of cpus, not just the maximum. + */ +struct lock_impl cpu_preemption_locks[NR_CPUS] = { + CPU_PREEMPTION_LOCKS_INIT0 +#if (NR_CPUS - 1) & 1 + , CPU_PREEMPTION_LOCKS_INIT0 +#endif +#if (NR_CPUS - 1) & 2 + , CPU_PREEMPTION_LOCKS_INIT1 +#endif +#if (NR_CPUS - 1) & 4 + , CPU_PREEMPTION_LOCKS_INIT2 +#endif +#if (NR_CPUS - 1) & 8 + , CPU_PREEMPTION_LOCKS_INIT3 +#endif +#if (NR_CPUS - 1) & 16 + , CPU_PREEMPTION_LOCKS_INIT4 +#endif +#if (NR_CPUS - 1) & 32 + , CPU_PREEMPTION_LOCKS_INIT5 +#endif +}; + +#undef CPU_PREEMPTION_LOCKS_INIT0 +#undef CPU_PREEMPTION_LOCKS_INIT1 +#undef CPU_PREEMPTION_LOCKS_INIT2 +#undef CPU_PREEMPTION_LOCKS_INIT3 +#undef CPU_PREEMPTION_LOCKS_INIT4 +#undef CPU_PREEMPTION_LOCKS_INIT5 + +__thread int thread_cpu_id; +__thread int preempt_disable_count; + +void preempt_disable(void) +{ + BUG_ON(preempt_disable_count < 0 || preempt_disable_count == INT_MAX); + + if (preempt_disable_count++) + return; + + thread_cpu_id = nondet_int(); + assume(thread_cpu_id >= 0); + assume(thread_cpu_id < NR_CPUS); + lock_impl_lock(&cpu_preemption_locks[thread_cpu_id]); +} + +void preempt_enable(void) +{ + BUG_ON(preempt_disable_count < 1); + + if (--preempt_disable_count) + return; + + lock_impl_unlock(&cpu_preemption_locks[thread_cpu_id]); +} diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.h new file mode 100644 index 000000000000..2f95ee0e4dd5 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.h @@ -0,0 +1,58 @@ +#ifndef PREEMPT_H +#define PREEMPT_H + +#include <stdbool.h> + +#include "bug_on.h" + +/* This flag contains garbage if preempt_disable_count is 0. */ +extern __thread int thread_cpu_id; + +/* Support recursive preemption disabling. */ +extern __thread int preempt_disable_count; + +void preempt_disable(void); +void preempt_enable(void); + +static inline void preempt_disable_notrace(void) +{ + preempt_disable(); +} + +static inline void preempt_enable_no_resched(void) +{ + preempt_enable(); +} + +static inline void preempt_enable_notrace(void) +{ + preempt_enable(); +} + +static inline int preempt_count(void) +{ + return preempt_disable_count; +} + +static inline bool preemptible(void) +{ + return !preempt_count(); +} + +static inline int get_cpu(void) +{ + preempt_disable(); + return thread_cpu_id; +} + +static inline void put_cpu(void) +{ + preempt_enable(); +} + +static inline void might_sleep(void) +{ + BUG_ON(preempt_disable_count); +} + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/simple_sync_srcu.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/simple_sync_srcu.c new file mode 100644 index 000000000000..ac9cbc62b411 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/simple_sync_srcu.c @@ -0,0 +1,50 @@ +#include <config.h> + +#include <assert.h> +#include <errno.h> +#include <inttypes.h> +#include <pthread.h> +#include <stddef.h> +#include <string.h> +#include <sys/types.h> + +#include "int_typedefs.h" + +#include "barriers.h" +#include "bug_on.h" +#include "locks.h" +#include "misc.h" +#include "preempt.h" +#include "percpu.h" +#include "workqueues.h" + +#include <linux/srcu.h> + +/* Functions needed from modify_srcu.c */ +bool try_check_zero(struct srcu_struct *sp, int idx, int trycount); +void srcu_flip(struct srcu_struct *sp); + +/* Simpler implementation of synchronize_srcu that ignores batching. */ +void synchronize_srcu(struct srcu_struct *sp) +{ + int idx; + /* + * This code assumes that try_check_zero will succeed anyway, + * so there is no point in multiple tries. + */ + const int trycount = 1; + + might_sleep(); + + /* Ignore the lock, as multiple writers aren't working yet anyway. */ + + idx = 1 ^ (sp->completed & 1); + + /* For comments see srcu_advance_batches. */ + + assume(try_check_zero(sp, idx, trycount)); + + srcu_flip(sp); + + assume(try_check_zero(sp, idx^1, trycount)); +} diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/workqueues.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/workqueues.h new file mode 100644 index 000000000000..e58c8dfd3e90 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/workqueues.h @@ -0,0 +1,102 @@ +#ifndef WORKQUEUES_H +#define WORKQUEUES_H + +#include <stdbool.h> + +#include "barriers.h" +#include "bug_on.h" +#include "int_typedefs.h" + +#include <linux/types.h> + +/* Stub workqueue implementation. */ + +struct work_struct; +typedef void (*work_func_t)(struct work_struct *work); +void delayed_work_timer_fn(unsigned long __data); + +struct work_struct { +/* atomic_long_t data; */ + unsigned long data; + + struct list_head entry; + work_func_t func; +#ifdef CONFIG_LOCKDEP + struct lockdep_map lockdep_map; +#endif +}; + +struct timer_list { + struct hlist_node entry; + unsigned long expires; + void (*function)(unsigned long); + unsigned long data; + u32 flags; + int slack; +}; + +struct delayed_work { + struct work_struct work; + struct timer_list timer; + + /* target workqueue and CPU ->timer uses to queue ->work */ + struct workqueue_struct *wq; + int cpu; +}; + + +static inline bool schedule_work(struct work_struct *work) +{ + BUG(); + return true; +} + +static inline bool schedule_work_on(int cpu, struct work_struct *work) +{ + BUG(); + return true; +} + +static inline bool queue_work(struct workqueue_struct *wq, + struct work_struct *work) +{ + BUG(); + return true; +} + +static inline bool queue_delayed_work(struct workqueue_struct *wq, + struct delayed_work *dwork, + unsigned long delay) +{ + BUG(); + return true; +} + +#define INIT_WORK(w, f) \ + do { \ + (w)->data = 0; \ + (w)->func = (f); \ + } while (0) + +#define INIT_DELAYED_WORK(w, f) INIT_WORK(&(w)->work, (f)) + +#define __WORK_INITIALIZER(n, f) { \ + .data = 0, \ + .entry = { &(n).entry, &(n).entry }, \ + .func = f \ + } + +/* Don't bother initializing timer. */ +#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \ + .work = __WORK_INITIALIZER((n).work, (f)), \ + } + +#define DECLARE_WORK(n, f) \ + struct workqueue_struct n = __WORK_INITIALIZER + +#define DECLARE_DELAYED_WORK(n, f) \ + struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0) + +#define system_power_efficient_wq ((struct workqueue_struct *) NULL) + +#endif diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/.gitignore b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/.gitignore new file mode 100644 index 000000000000..f47cb2045f13 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/.gitignore @@ -0,0 +1 @@ +*.out diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/Makefile b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/Makefile new file mode 100644 index 000000000000..3a3aee149225 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/Makefile @@ -0,0 +1,11 @@ +CBMC_FLAGS = -I../.. -I../../src -I../../include -I../../empty_includes -32 -pointer-check -mm pso + +all: + for i in ./*.pass; do \ + echo $$i ; \ + CBMC_FLAGS="$(CBMC_FLAGS)" sh ../test_script.sh --should-pass $$i > $$i.out 2>&1 ; \ + done + for i in ./*.fail; do \ + echo $$i ; \ + CBMC_FLAGS="$(CBMC_FLAGS)" sh ../test_script.sh --should-fail $$i > $$i.out 2>&1 ; \ + done diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/assert_end.fail b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/assert_end.fail new file mode 100644 index 000000000000..40c8075919d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/assert_end.fail @@ -0,0 +1 @@ +test_cbmc_options="-DASSERT_END" diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force.fail b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force.fail new file mode 100644 index 000000000000..ada5baf0b60d --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force.fail @@ -0,0 +1 @@ +test_cbmc_options="-DFORCE_FAILURE" diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force2.fail b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force2.fail new file mode 100644 index 000000000000..8fe00c8db466 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force2.fail @@ -0,0 +1 @@ +test_cbmc_options="-DFORCE_FAILURE_2" diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force3.fail b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force3.fail new file mode 100644 index 000000000000..612ed6772844 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/force3.fail @@ -0,0 +1 @@ +test_cbmc_options="-DFORCE_FAILURE_3" diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/main.pass b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/main.pass new file mode 100644 index 000000000000..e69de29bb2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/main.pass diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/test.c b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/test.c new file mode 100644 index 000000000000..470b1105a112 --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/test.c @@ -0,0 +1,72 @@ +#include <src/combined_source.c> + +int x; +int y; + +int __unbuffered_tpr_x; +int __unbuffered_tpr_y; + +DEFINE_SRCU(ss); + +void rcu_reader(void) +{ + int idx; + +#ifndef FORCE_FAILURE_3 + idx = srcu_read_lock(&ss); +#endif + might_sleep(); + + __unbuffered_tpr_y = READ_ONCE(y); +#ifdef FORCE_FAILURE + srcu_read_unlock(&ss, idx); + idx = srcu_read_lock(&ss); +#endif + WRITE_ONCE(x, 1); + +#ifndef FORCE_FAILURE_3 + srcu_read_unlock(&ss, idx); +#endif + might_sleep(); +} + +void *thread_update(void *arg) +{ + WRITE_ONCE(y, 1); +#ifndef FORCE_FAILURE_2 + synchronize_srcu(&ss); +#endif + might_sleep(); + __unbuffered_tpr_x = READ_ONCE(x); + + return NULL; +} + +void *thread_process_reader(void *arg) +{ + rcu_reader(); + + return NULL; +} + +int main(int argc, char *argv[]) +{ + pthread_t tu; + pthread_t tpr; + + if (pthread_create(&tu, NULL, thread_update, NULL)) + abort(); + if (pthread_create(&tpr, NULL, thread_process_reader, NULL)) + abort(); + if (pthread_join(tu, NULL)) + abort(); + if (pthread_join(tpr, NULL)) + abort(); + assert(__unbuffered_tpr_y != 0 || __unbuffered_tpr_x != 0); + +#ifdef ASSERT_END + assert(0); +#endif + + return 0; +} diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/test_script.sh b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/test_script.sh new file mode 100755 index 000000000000..d1545972a0fa --- /dev/null +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/test_script.sh @@ -0,0 +1,102 @@ +#!/bin/sh + +# This script expects a mode (either --should-pass or --should-fail) followed by +# an input file. The script uses the following environment variables. The test C +# source file is expected to be named test.c in the directory containing the +# input file. +# +# CBMC: The command to run CBMC. Default: cbmc +# CBMC_FLAGS: Additional flags to pass to CBMC +# NR_CPUS: Number of cpus to run tests with. Default specified by the test +# SYNC_SRCU_MODE: Choose implementation of synchronize_srcu. Defaults to simple. +# kernel: Version included in the linux kernel source. +# simple: Use try_check_zero directly. +# +# The input file is a script that is sourced by this file. It can define any of +# the following variables to configure the test. +# +# test_cbmc_options: Extra options to pass to CBMC. +# min_cpus_fail: Minimum number of CPUs (NR_CPUS) for verification to fail. +# The test is expected to pass if it is run with fewer. (Only +# useful for .fail files) +# default_cpus: Quantity of CPUs to use for the test, if not specified on the +# command line. Default: Larger of 2 and MIN_CPUS_FAIL. + +set -e + +if test "$#" -ne 2; then + echo "Expected one option followed by an input file" 1>&2 + exit 99 +fi + +if test "x$1" = "x--should-pass"; then + should_pass="yes" +elif test "x$1" = "x--should-fail"; then + should_pass="no" +else + echo "Unrecognized argument '$1'" 1>&2 + + # Exit code 99 indicates a hard error. + exit 99 +fi + +CBMC=${CBMC:-cbmc} + +SYNC_SRCU_MODE=${SYNC_SRCU_MODE:-simple} + +case ${SYNC_SRCU_MODE} in +kernel) sync_srcu_mode_flags="" ;; +simple) sync_srcu_mode_flags="-DUSE_SIMPLE_SYNC_SRCU" ;; + +*) + echo "Unrecognized argument '${SYNC_SRCU_MODE}'" 1>&2 + exit 99 + ;; +esac + +min_cpus_fail=1 + +c_file=`dirname "$2"`/test.c + +# Source the input file. +. $2 + +if test ${min_cpus_fail} -gt 2; then + default_default_cpus=${min_cpus_fail} +else + default_default_cpus=2 +fi +default_cpus=${default_cpus:-${default_default_cpus}} +cpus=${NR_CPUS:-${default_cpus}} + +# Check if there are two few cpus to make the test fail. +if test $cpus -lt ${min_cpus_fail:-0}; then + should_pass="yes" +fi + +cbmc_opts="-DNR_CPUS=${cpus} ${sync_srcu_mode_flags} ${test_cbmc_options} ${CBMC_FLAGS}" + +echo "Running CBMC: ${CBMC} ${cbmc_opts} ${c_file}" +if ${CBMC} ${cbmc_opts} "${c_file}"; then + # Verification successful. Make sure that it was supposed to verify. + test "x${should_pass}" = xyes +else + cbmc_exit_status=$? + + # An exit status of 10 indicates a failed verification. + # (see cbmc_parse_optionst::do_bmc in the CBMC source code) + if test ${cbmc_exit_status} -eq 10 && test "x${should_pass}" = xno; then + : + else + echo "CBMC returned ${cbmc_exit_status} exit status" 1>&2 + + # Parse errors have exit status 6. Any other type of error + # should be considered a hard error. + if test ${cbmc_exit_status} -ne 6 && \ + test ${cbmc_exit_status} -ne 10; then + exit 99 + else + exit 1 + fi + fi +fi |