diff --git a/linux-user/gen-vdso-elfn.c.inc b/linux-user/gen-vdso-elfn.c.inc index 95856eb839..b47019e136 100644 --- a/linux-user/gen-vdso-elfn.c.inc +++ b/linux-user/gen-vdso-elfn.c.inc @@ -68,28 +68,45 @@ static void elfN(search_symtab)(ElfN(Shdr) *shdr, unsigned sym_idx, void *buf, bool need_bswap) { unsigned str_idx = shdr[sym_idx].sh_link; - ElfN(Sym) *sym = buf + shdr[sym_idx].sh_offset; - unsigned sym_n = shdr[sym_idx].sh_size / sizeof(*sym); + ElfN(Sym) *target_sym = buf + shdr[sym_idx].sh_offset; + unsigned sym_n = shdr[sym_idx].sh_size / sizeof(*target_sym); const char *str = buf + shdr[str_idx].sh_offset; for (unsigned i = 0; i < sym_n; ++i) { const char *name; + ElfN(Sym) sym; + memcpy(&sym, &target_sym[i], sizeof(sym)); if (need_bswap) { - elfN(bswap_sym)(sym + i); + elfN(bswap_sym)(&sym); } - name = str + sym[i].st_name; + name = str + sym.st_name; if (sigreturn_sym && strcmp(sigreturn_sym, name) == 0) { - sigreturn_addr = sym[i].st_value; + sigreturn_addr = sym.st_value; } if (rt_sigreturn_sym && strcmp(rt_sigreturn_sym, name) == 0) { - rt_sigreturn_addr = sym[i].st_value; + rt_sigreturn_addr = sym.st_value; } } } -static void elfN(process)(FILE *outf, void *buf, bool need_bswap) +static void elfN(bswap_ps_hdrs)(ElfN(Ehdr) *ehdr) +{ + ElfN(Phdr) *phdr = (void *)ehdr + ehdr->e_phoff; + ElfN(Shdr) *shdr = (void *)ehdr + ehdr->e_shoff; + ElfN(Half) i; + + for (i = 0; i < ehdr->e_phnum; ++i) { + elfN(bswap_phdr)(&phdr[i]); + } + + for (i = 0; i < ehdr->e_shnum; ++i) { + elfN(bswap_shdr)(&shdr[i]); + } +} + +static void elfN(process)(FILE *outf, void *buf, long len, bool need_bswap) { ElfN(Ehdr) *ehdr = buf; ElfN(Phdr) *phdr; @@ -103,24 +120,14 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) int errors = 0; if (need_bswap) { - elfN(bswap_ehdr)(ehdr); + elfN(bswap_ehdr)(buf); + elfN(bswap_ps_hdrs)(buf); } phnum = ehdr->e_phnum; phdr = buf + ehdr->e_phoff; - if (need_bswap) { - for (unsigned i = 0; i < phnum; ++i) { - elfN(bswap_phdr)(phdr + i); - } - } - shnum = ehdr->e_shnum; shdr = buf + ehdr->e_shoff; - if (need_bswap) { - for (unsigned i = 0; i < shnum; ++i) { - elfN(bswap_shdr)(shdr + i); - } - } for (unsigned i = 0; i < shnum; ++i) { switch (shdr[i].sh_type) { case SHT_SYMTAB: @@ -154,7 +161,24 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) fprintf(stderr, "LOAD segment not loaded at address 0\n"); errors++; } - first_segsz = phdr[i].p_filesz; + /* + * Extend the program header to cover the entire VDSO, so that + * load_elf_vdso() loads everything, including section headers. + * + * Require that there is no .bss, since it would break this + * approach. + */ + if (phdr[i].p_filesz != phdr[i].p_memsz) { + fprintf(stderr, "LOAD segment's filesz and memsz differ\n"); + errors++; + } + if (phdr[i].p_filesz > len) { + fprintf(stderr, "LOAD segment is larger than the whole VDSO\n"); + errors++; + } + phdr[i].p_filesz = len; + phdr[i].p_memsz = len; + first_segsz = len; if (first_segsz < ehdr->e_phoff + phnum * sizeof(*phdr)) { fprintf(stderr, "LOAD segment does not cover PHDRs\n"); errors++; @@ -197,17 +221,24 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) output_reloc(outf, buf, &phdr[i].p_paddr); } + /* Relocate the section headers. */ + for (unsigned i = 0; i < shnum; ++i) { + output_reloc(outf, buf, &shdr[i].sh_addr); + } + /* Relocate the DYNAMIC entries. */ if (dynamic_addr) { - ElfN(Dyn) *dyn = buf + dynamic_ofs; - __typeof(dyn->d_tag) tag; + ElfN(Dyn) *target_dyn = buf + dynamic_ofs; + __typeof(((ElfN(Dyn) *)target_dyn)->d_tag) tag; do { + ElfN(Dyn) dyn; + memcpy(&dyn, target_dyn, sizeof(dyn)); if (need_bswap) { - elfN(bswap_dyn)(dyn); + elfN(bswap_dyn)(&dyn); } - tag = dyn->d_tag; + tag = dyn.d_tag; switch (tag) { case DT_HASH: @@ -218,7 +249,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) case DT_PLTGOT: case DT_ADDRRNGLO ... DT_ADDRRNGHI: /* These entries store an address in the entry. */ - output_reloc(outf, buf, &dyn->d_un.d_val); + output_reloc(outf, buf, &target_dyn->d_un.d_val); break; case DT_NULL: @@ -235,7 +266,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) break; case DT_SYMENT: - if (dyn->d_un.d_val != sizeof(ElfN(Sym))) { + if (dyn.d_un.d_val != sizeof(ElfN(Sym))) { fprintf(stderr, "VDSO has incorrect dynamic symbol size\n"); errors++; } @@ -251,7 +282,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) * ??? The RISC-V toolchain will emit these even when there * are no relocations. Validate zeros. */ - if (dyn->d_un.d_val != 0) { + if (dyn.d_un.d_val != 0) { fprintf(stderr, "VDSO has dynamic relocations\n"); errors++; } @@ -287,7 +318,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) errors++; break; } - dyn++; + target_dyn++; } while (tag != DT_NULL); if (errors) { exit(EXIT_FAILURE); @@ -296,11 +327,11 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) /* Relocate the dynamic symbol table. */ if (dynsym_idx) { - ElfN(Sym) *sym = buf + shdr[dynsym_idx].sh_offset; - unsigned sym_n = shdr[dynsym_idx].sh_size / sizeof(*sym); + ElfN(Sym) *target_sym = buf + shdr[dynsym_idx].sh_offset; + unsigned sym_n = shdr[dynsym_idx].sh_size / sizeof(*target_sym); for (unsigned i = 0; i < sym_n; ++i) { - output_reloc(outf, buf, &sym[i].st_value); + output_reloc(outf, buf, &target_sym[i].st_value); } } @@ -311,4 +342,9 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap) if (symtab_idx) { elfN(search_symtab)(shdr, symtab_idx, buf, need_bswap); } + + if (need_bswap) { + elfN(bswap_ps_hdrs)(buf); + elfN(bswap_ehdr)(buf); + } } diff --git a/linux-user/gen-vdso.c b/linux-user/gen-vdso.c index 31e333be80..721f38d5a3 100644 --- a/linux-user/gen-vdso.c +++ b/linux-user/gen-vdso.c @@ -131,23 +131,6 @@ int main(int argc, char **argv) } fclose(inf); - /* - * Write out the vdso image now, before we make local changes. - */ - - fprintf(outf, - "/* Automatically generated from linux-user/gen-vdso.c. */\n" - "\n" - "static const uint8_t %s_image[] = {", - prefix); - for (long i = 0; i < total_len; ++i) { - if (i % 12 == 0) { - fputs("\n ", outf); - } - fprintf(outf, " 0x%02x,", buf[i]); - } - fprintf(outf, "\n};\n\n"); - /* * Identify which elf flavor we're processing. * The first 16 bytes of the file are e_ident. @@ -179,14 +162,17 @@ int main(int argc, char **argv) * Output relocation addresses as we go. */ - fprintf(outf, "static const unsigned %s_relocs[] = {\n", prefix); + fprintf(outf, + "/* Automatically generated by linux-user/gen-vdso.c. */\n" + "\n" + "static const unsigned %s_relocs[] = {\n", prefix); switch (buf[EI_CLASS]) { case ELFCLASS32: - elf32_process(outf, buf, need_bswap); + elf32_process(outf, buf, total_len, need_bswap); break; case ELFCLASS64: - elf64_process(outf, buf, need_bswap); + elf64_process(outf, buf, total_len, need_bswap); break; default: fprintf(stderr, "%s: invalid elf EI_CLASS (%u)\n", @@ -196,6 +182,20 @@ int main(int argc, char **argv) fprintf(outf, "};\n\n"); /* end vdso_relocs. */ + /* + * Write out the vdso image now, after we made local changes. + */ + fprintf(outf, + "static const uint8_t %s_image[] = {", + prefix); + for (long i = 0; i < total_len; ++i) { + if (i % 12 == 0) { + fputs("\n ", outf); + } + fprintf(outf, " 0x%02x,", buf[i]); + } + fprintf(outf, "\n};\n\n"); + fprintf(outf, "static const VdsoImageInfo %s_image_info = {\n", prefix); fprintf(outf, " .image = %s_image,\n", prefix); fprintf(outf, " .relocs = %s_relocs,\n", prefix); diff --git a/linux-user/main.c b/linux-user/main.c index 8143a0d4b0..b09af8d436 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -412,6 +412,13 @@ static void handle_arg_reserved_va(const char *arg) reserved_va = val ? val - 1 : 0; } +static const char *rtsig_map = CONFIG_QEMU_RTSIG_MAP; + +static void handle_arg_rtsig_map(const char *arg) +{ + rtsig_map = arg; +} + static void handle_arg_one_insn_per_tb(const char *arg) { opt_one_insn_per_tb = true; @@ -494,6 +501,9 @@ static const struct qemu_argument arg_table[] = { "address", "set guest_base address to 'address'"}, {"R", "QEMU_RESERVED_VA", true, handle_arg_reserved_va, "size", "reserve 'size' bytes for guest virtual address space"}, + {"t", "QEMU_RTSIG_MAP", true, handle_arg_rtsig_map, + "tsig hsig n[,...]", + "map target rt signals [tsig,tsig+n) to [hsig,hsig+n]"}, {"d", "QEMU_LOG", true, handle_arg_log, "item[,...]", "enable logging of specified items " "(use '-d help' for a list of items)"}, @@ -1002,7 +1012,7 @@ int main(int argc, char **argv, char **envp) target_set_brk(info->brk); syscall_init(); - signal_init(); + signal_init(rtsig_map); /* Now that we've loaded the binary, GUEST_BASE is fixed. Delay generating the prologue until now so that the prologue can take diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h index f4cbe6185e..8584d9ecc2 100644 --- a/linux-user/signal-common.h +++ b/linux-user/signal-common.h @@ -56,7 +56,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUArchState *env); void process_pending_signals(CPUArchState *cpu_env); -void signal_init(void); +void signal_init(const char *rtsig_map); void queue_signal(CPUArchState *env, int sig, int si_type, target_siginfo_t *info); void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info); diff --git a/linux-user/signal.c b/linux-user/signal.c index 63ac2df53b..9b6d772882 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu/bitops.h" +#include "qemu/cutils.h" #include "gdbstub/user.h" #include "exec/page-protection.h" #include "hw/core/tcg-cpu-ops.h" @@ -513,20 +514,81 @@ static int core_dump_signal(int sig) } } -static void signal_table_init(void) +static void signal_table_init(const char *rtsig_map) { int hsig, tsig, count; + if (rtsig_map) { + /* + * Map host RT signals to target RT signals according to the + * user-provided specification. + */ + const char *s = rtsig_map; + + while (true) { + int i; + + if (qemu_strtoi(s, &s, 10, &tsig) || *s++ != ' ') { + fprintf(stderr, "Malformed target signal in QEMU_RTSIG_MAP\n"); + exit(EXIT_FAILURE); + } + if (qemu_strtoi(s, &s, 10, &hsig) || *s++ != ' ') { + fprintf(stderr, "Malformed host signal in QEMU_RTSIG_MAP\n"); + exit(EXIT_FAILURE); + } + if (qemu_strtoi(s, &s, 10, &count) || (*s && *s != ',')) { + fprintf(stderr, "Malformed signal count in QEMU_RTSIG_MAP\n"); + exit(EXIT_FAILURE); + } + + for (i = 0; i < count; i++, tsig++, hsig++) { + if (tsig < TARGET_SIGRTMIN || tsig > TARGET_NSIG) { + fprintf(stderr, "%d is not a target rt signal\n", tsig); + exit(EXIT_FAILURE); + } + if (hsig < SIGRTMIN || hsig > SIGRTMAX) { + fprintf(stderr, "%d is not a host rt signal\n", hsig); + exit(EXIT_FAILURE); + } + if (host_to_target_signal_table[hsig]) { + fprintf(stderr, "%d already maps %d\n", + hsig, host_to_target_signal_table[hsig]); + exit(EXIT_FAILURE); + } + host_to_target_signal_table[hsig] = tsig; + } + + if (*s) { + s++; + } else { + break; + } + } + } else { + /* + * Default host-to-target RT signal mapping. + * + * Signals are supported starting from TARGET_SIGRTMIN and going up + * until we run out of host realtime signals. Glibc uses the lower 2 + * RT signals and (hopefully) nobody uses the upper ones. + * This is why SIGRTMIN (34) is generally greater than __SIGRTMIN (32). + * To fix this properly we would need to do manual signal delivery + * multiplexed over a single host signal. + * Attempts for configure "missing" signals via sigaction will be + * silently ignored. + * + * Reserve one signal for internal usage (see below). + */ + + hsig = SIGRTMIN + 1; + for (tsig = TARGET_SIGRTMIN; + hsig <= SIGRTMAX && tsig <= TARGET_NSIG; + hsig++, tsig++) { + host_to_target_signal_table[hsig] = tsig; + } + } + /* - * Signals are supported starting from TARGET_SIGRTMIN and going up - * until we run out of host realtime signals. Glibc uses the lower 2 - * RT signals and (hopefully) nobody uses the upper ones. - * This is why SIGRTMIN (34) is generally greater than __SIGRTMIN (32). - * To fix this properly we would need to do manual signal delivery - * multiplexed over a single host signal. - * Attempts for configure "missing" signals via sigaction will be - * silently ignored. - * * Remap the target SIGABRT, so that we can distinguish host abort * from guest abort. When the guest registers a signal handler or * calls raise(SIGABRT), the host will raise SIG_RTn. If the guest @@ -536,21 +598,27 @@ static void signal_table_init(void) * parent sees the correct mapping from wait status. */ - hsig = SIGRTMIN; host_to_target_signal_table[SIGABRT] = 0; - host_to_target_signal_table[hsig++] = TARGET_SIGABRT; - - for (tsig = TARGET_SIGRTMIN; - hsig <= SIGRTMAX && tsig <= TARGET_NSIG; - hsig++, tsig++) { - host_to_target_signal_table[hsig] = tsig; + for (hsig = SIGRTMIN; hsig <= SIGRTMAX; hsig++) { + if (!host_to_target_signal_table[hsig]) { + host_to_target_signal_table[hsig] = TARGET_SIGABRT; + break; + } + } + if (hsig > SIGRTMAX) { + fprintf(stderr, "No rt signals left for SIGABRT mapping\n"); + exit(EXIT_FAILURE); } /* Invert the mapping that has already been assigned. */ for (hsig = 1; hsig < _NSIG; hsig++) { tsig = host_to_target_signal_table[hsig]; if (tsig) { - assert(target_to_host_signal_table[tsig] == 0); + if (target_to_host_signal_table[tsig]) { + fprintf(stderr, "%d is already mapped to %d\n", + tsig, target_to_host_signal_table[tsig]); + exit(EXIT_FAILURE); + } target_to_host_signal_table[tsig] = hsig; } } @@ -573,13 +641,13 @@ static void signal_table_init(void) trace_signal_table_init(count); } -void signal_init(void) +void signal_init(const char *rtsig_map) { TaskState *ts = get_task_state(thread_cpu); struct sigaction act, oact; /* initialize signal conversion tables */ - signal_table_init(); + signal_table_init(rtsig_map); /* Set the signal mask from the host mask. */ sigprocmask(0, 0, &ts->signal_mask); diff --git a/meson.build b/meson.build index 27c2dcce0a..5cfffb4aa6 100644 --- a/meson.build +++ b/meson.build @@ -3178,7 +3178,8 @@ foreach target : target_dirs config_target += { 'CONFIG_USER_ONLY': 'y', 'CONFIG_QEMU_INTERP_PREFIX': - get_option('interp_prefix').replace('%M', config_target['TARGET_NAME']) + get_option('interp_prefix').replace('%M', config_target['TARGET_NAME']), + 'CONFIG_QEMU_RTSIG_MAP': get_option('rtsig_map'), } endif diff --git a/meson_options.txt b/meson_options.txt index 24bf009056..ac4887a622 100644 --- a/meson_options.txt +++ b/meson_options.txt @@ -27,6 +27,8 @@ option('block_drv_ro_whitelist', type : 'string', value : '', description: 'set block driver read-only whitelist (by default affects only QEMU, not tools like qemu-img)') option('interp_prefix', type : 'string', value : '/usr/gnemul/qemu-%M', description: 'where to find shared libraries etc., use %M for cpu name') +option('rtsig_map', type : 'string', value : 'NULL', + description: 'default value of QEMU_RTSIG_MAP') option('fuzzing_engine', type : 'string', value : '', description: 'fuzzing engine library for OSS-Fuzz') option('trace_file', type: 'string', value: 'trace', diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh index 6f2bb08ecd..51ed46e46a 100644 --- a/scripts/meson-buildoptions.sh +++ b/scripts/meson-buildoptions.sh @@ -72,6 +72,7 @@ meson_options_help() { printf "%s\n" ' "manufacturer" name for qemu-ga registry entries' printf "%s\n" ' [QEMU]' printf "%s\n" ' --qemu-ga-version=VALUE version number for qemu-ga installer' + printf "%s\n" ' --rtsig-map=VALUE default value of QEMU_RTSIG_MAP [NULL]' printf "%s\n" ' --smbd=VALUE Path to smbd for slirp networking' printf "%s\n" ' --sysconfdir=VALUE Sysconf data directory [etc]' printf "%s\n" ' --tls-priority=VALUE Default TLS protocol/cipher priority string' @@ -460,6 +461,7 @@ _meson_option_parse() { --disable-replication) printf "%s" -Dreplication=disabled ;; --enable-rng-none) printf "%s" -Drng_none=true ;; --disable-rng-none) printf "%s" -Drng_none=false ;; + --rtsig-map=*) quote_sh "-Drtsig_map=$2" ;; --enable-rust) printf "%s" -Drust=enabled ;; --disable-rust) printf "%s" -Drust=disabled ;; --enable-rutabaga-gfx) printf "%s" -Drutabaga_gfx=enabled ;; diff --git a/tests/tcg/Makefile.target b/tests/tcg/Makefile.target index 9722145b97..95ff76ea44 100644 --- a/tests/tcg/Makefile.target +++ b/tests/tcg/Makefile.target @@ -179,10 +179,10 @@ run-plugin-%-with-libmem.so: PLUGIN_ARGS=$(COMMA)inline=true ifeq ($(filter %-softmmu, $(TARGET)),) run-%: % - $(call run-test, $<, $(QEMU) $(QEMU_OPTS) $<) + $(call run-test, $<, env QEMU=$(QEMU) $(QEMU) $(QEMU_OPTS) $<) run-plugin-%: - $(call run-test, $@, $(QEMU) $(QEMU_OPTS) \ + $(call run-test, $@, env QEMU=$(QEMU) $(QEMU) $(QEMU_OPTS) \ -plugin $(PLUGIN_LIB)/$(call extract-plugin,$@)$(PLUGIN_ARGS) \ -d plugin -D $*.pout \ $(call strip-plugin,$<)) diff --git a/tests/tcg/multiarch/linux/linux-sigrtminmax.c b/tests/tcg/multiarch/linux/linux-sigrtminmax.c new file mode 100644 index 0000000000..a7059aacd9 --- /dev/null +++ b/tests/tcg/multiarch/linux/linux-sigrtminmax.c @@ -0,0 +1,74 @@ +/* + * Test the lowest and the highest real-time signals. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ +#include +#include +#include +#include +#include +#include +#include + +/* For hexagon and microblaze. */ +#ifndef __SIGRTMIN +#define __SIGRTMIN 32 +#endif + +extern char **environ; + +static bool seen_sigrtmin, seen_sigrtmax; + +static void handle_signal(int sig) +{ + if (sig == SIGRTMIN) { + seen_sigrtmin = true; + } else if (sig == SIGRTMAX) { + seen_sigrtmax = true; + } else { + _exit(1); + } +} + +int main(int argc, char **argv) +{ + char *qemu = getenv("QEMU"); + struct sigaction act; + + assert(qemu); + + if (!getenv("QEMU_RTSIG_MAP")) { + char **new_argv = malloc((argc + 2) + sizeof(char *)); + int tsig1, hsig1, count1, tsig2, hsig2, count2; + char rt_sigmap[64]; + + /* Re-exec with a mapping that includes SIGRTMIN and SIGRTMAX. */ + new_argv[0] = qemu; + memcpy(&new_argv[1], argv, (argc + 1) * sizeof(char *)); + tsig1 = __SIGRTMIN; + /* The host must have a few signals starting from this one. */ + hsig1 = 36; + count1 = SIGRTMIN - __SIGRTMIN + 1; + tsig2 = SIGRTMAX; + hsig2 = hsig1 + count1; + count2 = 1; + snprintf(rt_sigmap, sizeof(rt_sigmap), "%d %d %d,%d %d %d", + tsig1, hsig1, count1, tsig2, hsig2, count2); + setenv("QEMU_RTSIG_MAP", rt_sigmap, 0); + assert(execve(new_argv[0], new_argv, environ) == 0); + return EXIT_FAILURE; + } + + memset(&act, 0, sizeof(act)); + act.sa_handler = handle_signal; + assert(sigaction(SIGRTMIN, &act, NULL) == 0); + assert(sigaction(SIGRTMAX, &act, NULL) == 0); + + assert(kill(getpid(), SIGRTMIN) == 0); + assert(seen_sigrtmin); + assert(kill(getpid(), SIGRTMAX) == 0); + assert(seen_sigrtmax); + + return EXIT_SUCCESS; +}