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[PATCH v3 03/15] linux-user: Do not clobber bprm_buf swapping ehdr
From: |
Richard Henderson |
Subject: |
[PATCH v3 03/15] linux-user: Do not clobber bprm_buf swapping ehdr |
Date: |
Fri, 11 Aug 2023 09:50:40 -0700 |
Rearrange the allocation of storage for ehdr between load_elf_image
and load_elf_binary. The same set of copies are done, but we don't
modify bprm_buf, which will be important later.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/elfload.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index ac03beb01b..11bbf4e99b 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3019,16 +3019,17 @@ static bool parse_elf_properties(int image_fd,
On return: INFO values will be filled in, as necessary or available. */
static void load_elf_image(const char *image_name, int image_fd,
- struct image_info *info, char **pinterp_name,
+ struct image_info *info, struct elfhdr *ehdr,
+ char **pinterp_name,
char bprm_buf[BPRM_BUF_SIZE])
{
- struct elfhdr *ehdr = (struct elfhdr *)bprm_buf;
struct elf_phdr *phdr;
abi_ulong load_addr, load_bias, loaddr, hiaddr, error;
int i, retval, prot_exec;
Error *err = NULL;
/* First of all, some simple consistency checks */
+ memcpy(ehdr, bprm_buf, sizeof(*ehdr));
if (!elf_check_ident(ehdr)) {
error_setg(&err, "Invalid ELF image for this architecture");
goto exit_errmsg;
@@ -3343,6 +3344,7 @@ static void load_elf_image(const char *image_name, int
image_fd,
static void load_elf_interp(const char *filename, struct image_info *info,
char bprm_buf[BPRM_BUF_SIZE])
{
+ struct elfhdr ehdr;
int fd, retval;
Error *err = NULL;
@@ -3364,7 +3366,7 @@ static void load_elf_interp(const char *filename, struct
image_info *info,
memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval);
}
- load_elf_image(filename, fd, info, NULL, bprm_buf);
+ load_elf_image(filename, fd, info, &ehdr, NULL, bprm_buf);
}
static int symfind(const void *s0, const void *s1)
@@ -3557,8 +3559,14 @@ uint32_t get_elf_eflags(int fd)
int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
{
+ /*
+ * We need a copy of the elf header for passing to create_elf_tables.
+ * We will have overwritten the original when we re-use bprm->buf
+ * while loading the interpreter. Allocate the storage for this now
+ * and let elf_load_image do any swapping that may be required.
+ */
+ struct elfhdr ehdr;
struct image_info interp_info;
- struct elfhdr elf_ex;
char *elf_interpreter = NULL;
char *scratch;
@@ -3570,12 +3578,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct
image_info *info)
info->start_mmap = (abi_ulong)ELF_START_MMAP;
load_elf_image(bprm->filename, bprm->fd, info,
- &elf_interpreter, bprm->buf);
-
- /* ??? We need a copy of the elf header for passing to create_elf_tables.
- If we do nothing, we'll have overwritten this when we re-use bprm->buf
- when we load the interpreter. */
- elf_ex = *(struct elfhdr *)bprm->buf;
+ &ehdr, &elf_interpreter, bprm->buf);
/* Do this so that we can load the interpreter, if need be. We will
change some of these later */
@@ -3662,7 +3665,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct
image_info *info)
target_mprotect(tramp_page, TARGET_PAGE_SIZE, PROT_READ | PROT_EXEC);
}
- bprm->p = create_elf_tables(bprm->p, bprm->argc, bprm->envc, &elf_ex,
+ bprm->p = create_elf_tables(bprm->p, bprm->argc, bprm->envc, &ehdr,
info, (elf_interpreter ? &interp_info : NULL));
info->start_stack = bprm->p;
--
2.34.1
- [PATCH v3 00/15] linux-user: Implement VDSOs, Richard Henderson, 2023/08/11
- [PATCH v3 01/15] linux-user: Introduce imgsrc_read, imgsrc_read_alloc, Richard Henderson, 2023/08/11
- [PATCH v3 02/15] linux-user: Tidy loader_exec, Richard Henderson, 2023/08/11
- [PATCH v3 03/15] linux-user: Do not clobber bprm_buf swapping ehdr,
Richard Henderson <=
- [PATCH v3 05/15] linux-user: Use ImageSource in load_symbols, Richard Henderson, 2023/08/11
- [PATCH v3 07/15] linux-user: Load vdso image if available, Richard Henderson, 2023/08/11
- [PATCH v3 06/15] linux-user: Replace bprm->fd with bprm->src.fd, Richard Henderson, 2023/08/11
- [PATCH v3 04/15] linux-user: Use ImageSource in load_elf_image, Richard Henderson, 2023/08/11
- [PATCH v3 12/15] linux-user/hppa: Add vdso and use it for rt_sigreturn, Richard Henderson, 2023/08/11
- [PATCH v3 08/15] linux-user: Add gen-vdso tool, Richard Henderson, 2023/08/11
- [PATCH v3 09/15] linux-user/aarch64: Add vdso and use it for rt_sigreturn, Richard Henderson, 2023/08/11
- [PATCH v3 10/15] target/arm: Add isar_feature_aa32_a32, Richard Henderson, 2023/08/11
- [PATCH v3 13/15] linux-user/i386: Add vdso and use it for sigreturn, Richard Henderson, 2023/08/11
- [PATCH v3 14/15] linux-user/x86_64: Add vdso, Richard Henderson, 2023/08/11