Define BPRM_BUF_SIZE to 4k and read that amount initially. If the
data we want from the binary is in this buffer, use it instead of
reading from the file again.
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
linux-user/elfload.c | 105 ++++++++++++++++++++---------------------------
linux-user/linuxload.c | 17 +++-----
linux-user/qemu.h | 7 +++-
3 files changed, 58 insertions(+), 71 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index ab741fd..962f9ba 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1140,7 +1140,8 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc,
int envc,
static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
int interpreter_fd,
- abi_ulong *interp_load_addr)
+ abi_ulong *interp_load_addr,
+ char bprm_buf[BPRM_BUF_SIZE])
{
struct elf_phdr *elf_phdata = NULL;
struct elf_phdr *eppnt;
@@ -1183,17 +1184,15 @@ static abi_ulong load_elf_interp(struct elfhdr *
interp_elf_ex,
return ~((abi_ulong)0UL);
}
- retval = lseek(interpreter_fd, interp_elf_ex->e_phoff, SEEK_SET);
- if(retval >= 0) {
- retval = read(interpreter_fd,
- (char *) elf_phdata,
- sizeof(struct elf_phdr) * interp_elf_ex->e_phnum);
- }
- if (retval < 0) {
- perror("load_elf_interp");
- exit(-1);
- free (elf_phdata);
- return retval;
+ i = interp_elf_ex->e_phnum * sizeof(struct elf_phdr);
+ if (interp_elf_ex->e_phoff + i <= BPRM_BUF_SIZE) {
+ memcpy(elf_phdata, bprm_buf + interp_elf_ex->e_phoff, i);
+ } else {
+ retval = pread(interpreter_fd, elf_phdata, i, interp_elf_ex->e_phoff);
+ if (retval != i) {
+ perror("load_elf_interp");
+ exit(-1);
+ }
}
#ifdef BSWAP_NEEDED
eppnt = elf_phdata;
@@ -1451,17 +1450,15 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
return -ENOMEM;
}
- retval = lseek(bprm->fd, elf_ex.e_phoff, SEEK_SET);
- if(retval > 0) {
- retval = read(bprm->fd, (char *) elf_phdata,
- elf_ex.e_phentsize * elf_ex.e_phnum);
- }
-
- if (retval < 0) {
- perror("load_elf_binary");
- exit(-1);
- free (elf_phdata);
- return -errno;
+ i = elf_ex.e_phnum * sizeof(struct elf_phdr);
+ if (elf_ex.e_phoff + i <= BPRM_BUF_SIZE) {
+ memcpy(elf_phdata, bprm->buf + elf_ex.e_phoff, i);
+ } else {
+ retval = pread(bprm->fd, (char *) elf_phdata, i, elf_ex.e_phoff);
+ if (retval != i) {
+ perror("load_elf_binary");
+ exit(-1);
+ }
}
#ifdef BSWAP_NEEDED
@@ -1505,13 +1502,16 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
return -ENOMEM;
}
- retval = lseek(bprm->fd, elf_ppnt->p_offset, SEEK_SET);
- if(retval >= 0) {
- retval = read(bprm->fd, elf_interpreter, elf_ppnt->p_filesz);
- }
- if(retval < 0) {
- perror("load_elf_binary2");
- exit(-1);
+ if (elf_ppnt->p_offset + elf_ppnt->p_filesz <= BPRM_BUF_SIZE) {
+ memcpy(elf_interpreter, bprm->buf + elf_ppnt->p_offset,
+ elf_ppnt->p_filesz);
+ } else {
+ retval = pread(bprm->fd, elf_interpreter, elf_ppnt->p_filesz,
+ elf_ppnt->p_offset);
+ if (retval != elf_ppnt->p_filesz) {
+ perror("load_elf_binary2");
+ exit(-1);
+ }
}
/* If the program interpreter is one of these two,
@@ -1525,39 +1525,24 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
ibcs2_interpreter = 1;
}
-#if 0
- printf("Using ELF interpreter %s\n", path(elf_interpreter));
-#endif
- if (retval >= 0) {
- retval = open(path(elf_interpreter), O_RDONLY);
- if(retval >= 0) {
- interpreter_fd = retval;
- }
- else {
- perror(elf_interpreter);
- exit(-1);
- /* retval = -errno; */
- }
- }
+ retval = open(path(elf_interpreter), O_RDONLY);
+ if (retval < 0) {
+ perror(elf_interpreter);
+ exit(-1);
+ }
+ interpreter_fd = retval;
- if (retval >= 0) {
- retval = lseek(interpreter_fd, 0, SEEK_SET);
- if(retval >= 0) {
- retval = read(interpreter_fd,bprm->buf,128);
- }
- }
- if (retval >= 0) {
- interp_ex = *((struct exec *) bprm->buf); /* aout exec-header */
- interp_elf_ex = *((struct elfhdr *) bprm->buf); /* elf
exec-header */
- }
- if (retval < 0) {
+ retval = read(interpreter_fd, bprm->buf, BPRM_BUF_SIZE);
+ if (retval < 0) {
perror("load_elf_binary3");
exit(-1);
- free (elf_phdata);
- free(elf_interpreter);
- close(bprm->fd);
- return retval;
}
+ if (retval < BPRM_BUF_SIZE) {
+ memset(bprm->buf, 0, BPRM_BUF_SIZE - retval);
+ }
+
+ interp_ex = *((struct exec *) bprm->buf); /* aout exec-header */
+ interp_elf_ex = *((struct elfhdr *) bprm->buf); /* elf exec-header
*/
}
elf_ppnt++;
}
@@ -1746,7 +1731,7 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
}
else if (interpreter_type & 2) {
elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
- &interp_load_addr);
+ &interp_load_addr, bprm->buf);
}
reloc_func_desc = interp_load_addr;
diff --git a/linux-user/linuxload.c b/linux-user/linuxload.c
index 13ad9aa..9ee27c3 100644
--- a/linux-user/linuxload.c
+++ b/linux-user/linuxload.c
@@ -96,18 +96,16 @@ static int prepare_binprm(struct linux_binprm *bprm)
}
}
- retval = lseek(bprm->fd, 0L, SEEK_SET);
- if(retval >= 0) {
- retval = read(bprm->fd, bprm->buf, 128);
- }
- if(retval < 0) {
+ retval = read(bprm->fd, bprm->buf, BPRM_BUF_SIZE);
+ if (retval < 0) {
perror("prepare_binprm");
exit(-1);
- /* return(-errno); */
}
- else {
- return(retval);
+ if (retval < BPRM_BUF_SIZE) {
+ /* Make sure the rest of the loader won't read garbage. */
+ memset(bprm->buf + retval, 0, BPRM_BUF_SIZE - retval);
}
+ return retval;
}
/* Construct the envp and argv tables on the target stack. */
@@ -163,8 +161,7 @@ int loader_exec(const char * filename, char ** argv, char
** envp,
int i;
bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
- for (i=0 ; i<MAX_ARG_PAGES ; i++) /* clear page-table */
- bprm->page[i] = NULL;
+ memset(bprm->page, 0, sizeof(bprm->page));
retval = open(filename, O_RDONLY);
if (retval < 0)
return retval;
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index dab3597..f7c8b65 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -31,6 +31,7 @@
* task_struct fields in the kernel
*/
struct image_info {
+ abi_ulong load_bias;
abi_ulong load_addr;
abi_ulong start_code;
abi_ulong end_code;
@@ -143,12 +144,16 @@ extern unsigned long mmap_min_addr;
*/
#define MAX_ARG_PAGES 33
+/* Read a good amount of data initially, to hopefully get all the
+ program headers loaded. */
+#define BPRM_BUF_SIZE 4096
+
/*
* This structure is used to hold the arguments that are
* used when loading binaries.
*/
struct linux_binprm {
- char buf[128];
+ char buf[BPRM_BUF_SIZE] __attribute__((aligned));
void *page[MAX_ARG_PAGES];
abi_ulong p;
int fd;
--
1.6.6.1
