From 60f1c8017a2b137013a8ae83911d74700f692425 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 26 Apr 2022 19:51:29 -0700 Subject: [PATCH] linux-user: Clean up arg_start/arg_end confusion MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We had two sets of variables: arg_start/arg_end, and arg_strings/env_strings. In linuxload.c, we set the first pair to the bounds of the argv strings, but in elfload.c, we set the first pair to the bounds of the argv pointers and the second pair to the bounds of the argv strings. Remove arg_start/arg_end, replacing them with the standard argc/argv/envc/envp values. Retain arg_strings/env_strings with the meaning we were using in elfload.c. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/714 Reviewed-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson Message-Id: <20220427025129.160184-1-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 10 ++++++---- linux-user/linuxload.c | 12 ++++++++++-- linux-user/main.c | 4 ++-- linux-user/qemu.h | 12 ++++++++---- semihosting/arm-compat-semi.c | 4 ++-- 5 files changed, 28 insertions(+), 14 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 61063fd974..8c0765dd4b 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1516,8 +1516,8 @@ static inline void init_thread(struct target_pt_regs *regs, regs->iaoq[0] = infop->entry; regs->iaoq[1] = infop->entry + 4; regs->gr[23] = 0; - regs->gr[24] = infop->arg_start; - regs->gr[25] = (infop->arg_end - infop->arg_start) / sizeof(abi_ulong); + regs->gr[24] = infop->argv; + regs->gr[25] = infop->argc; /* The top-of-stack contains a linkage buffer. */ regs->gr[30] = infop->start_stack + 64; regs->gr[31] = infop->entry; @@ -2120,8 +2120,10 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, u_envp = u_argv + (argc + 1) * n; u_auxv = u_envp + (envc + 1) * n; info->saved_auxv = u_auxv; - info->arg_start = u_argv; - info->arg_end = u_argv + argc * n; + info->argc = argc; + info->envc = envc; + info->argv = u_argv; + info->envp = u_envp; /* This is correct because Linux defines * elf_addr_t as Elf32_Off / Elf64_Off diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c index 2ed5fc45ed..745cce70ab 100644 --- a/linux-user/linuxload.c +++ b/linux-user/linuxload.c @@ -92,6 +92,11 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, envp = sp; sp -= (argc + 1) * n; argv = sp; + ts->info->envp = envp; + ts->info->envc = envc; + ts->info->argv = argv; + ts->info->argc = argc; + if (push_ptr) { /* FIXME - handle put_user() failures */ sp -= n; @@ -99,19 +104,22 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, sp -= n; put_user_ual(argv, sp); } + sp -= n; /* FIXME - handle put_user() failures */ put_user_ual(argc, sp); - ts->info->arg_start = stringp; + + ts->info->arg_strings = stringp; while (argc-- > 0) { /* FIXME - handle put_user() failures */ put_user_ual(stringp, argv); argv += n; stringp += target_strlen(stringp) + 1; } - ts->info->arg_end = stringp; /* FIXME - handle put_user() failures */ put_user_ual(0, argv); + + ts->info->env_strings = stringp; while (envc-- > 0) { /* FIXME - handle put_user() failures */ put_user_ual(stringp, envp); diff --git a/linux-user/main.c b/linux-user/main.c index 7ca48664e4..651e32f5f2 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -878,9 +878,9 @@ int main(int argc, char **argv, char **envp) fprintf(f, "entry 0x" TARGET_ABI_FMT_lx "\n", info->entry); fprintf(f, "argv_start 0x" TARGET_ABI_FMT_lx "\n", - info->arg_start); + info->argv); fprintf(f, "env_start 0x" TARGET_ABI_FMT_lx "\n", - info->arg_end + (abi_ulong)sizeof(abi_ulong)); + info->envp); fprintf(f, "auxv_start 0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv); qemu_log_unlock(f); diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 46550f5e21..7d90de1b15 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -40,15 +40,19 @@ struct image_info { abi_ulong data_offset; abi_ulong saved_auxv; abi_ulong auxv_len; - abi_ulong arg_start; - abi_ulong arg_end; - abi_ulong arg_strings; - abi_ulong env_strings; + abi_ulong argc; + abi_ulong argv; + abi_ulong envc; + abi_ulong envp; abi_ulong file_string; uint32_t elf_flags; int personality; abi_ulong alignment; + /* Generic semihosting knows about these pointers. */ + abi_ulong arg_strings; /* strings for argv */ + abi_ulong env_strings; /* strings for envp; ends arg_strings */ + /* The fields below are used in FDPIC mode. */ abi_ulong loadmap_addr; uint16_t nsegs; diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c index 7a51fd0737..b6ddaf863a 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -1106,7 +1106,7 @@ target_ulong do_common_semihosting(CPUState *cs) #else unsigned int i; - output_size = ts->info->arg_end - ts->info->arg_start; + output_size = ts->info->env_strings - ts->info->arg_strings; if (!output_size) { /* * We special-case the "empty command line" case (argc==0). @@ -1146,7 +1146,7 @@ target_ulong do_common_semihosting(CPUState *cs) goto out; } - if (copy_from_user(output_buffer, ts->info->arg_start, + if (copy_from_user(output_buffer, ts->info->arg_strings, output_size)) { errno = EFAULT; status = set_swi_errno(cs, -1);