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authorChristophe Lyon2018-04-30 10:03:43 +0200
committerLaurent Vivier2018-05-03 18:25:29 +0200
commit3cb10cfafd83b9d7b3867b7deae29b8da3b5fe39 (patch)
tree5dbd214f79a0d48c2f806de091b04815e13f0b91 /linux-user
parentlinux-user: ARM-FDPIC: Identify ARM FDPIC binaries (diff)
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linux-user: ARM-FDPIC: Add support of FDPIC for ARM.
Add FDPIC info into image_info structure since interpreter info is on stack and needs to be saved to be accessed later on. Co-Authored-By: Mickaël Guêné <mickael.guene@st.com> Signed-off-by: Christophe Lyon <christophe.lyon@st.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180430080404.7323-4-christophe.lyon@st.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/elfload.c29
-rw-r--r--linux-user/qemu.h9
2 files changed, 38 insertions, 0 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 76d7718b3d..36d52194bc 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -78,6 +78,11 @@ enum {
*/
#define personality(pers) (pers & PER_MASK)
+int info_is_fdpic(struct image_info *info)
+{
+ return info->personality == PER_LINUX_FDPIC;
+}
+
/* this flag is uneffective under linux too, should be deleted */
#ifndef MAP_DENYWRITE
#define MAP_DENYWRITE 0
@@ -287,6 +292,25 @@ static inline void init_thread(struct target_pt_regs *regs,
/* For uClinux PIC binaries. */
/* XXX: Linux does this only on ARM with no MMU (do we care ?) */
regs->uregs[10] = infop->start_data;
+
+ /* Support ARM FDPIC. */
+ if (info_is_fdpic(infop)) {
+ /* As described in the ABI document, r7 points to the loadmap info
+ * prepared by the kernel. If an interpreter is needed, r8 points
+ * to the interpreter loadmap and r9 points to the interpreter
+ * PT_DYNAMIC info. If no interpreter is needed, r8 is zero, and
+ * r9 points to the main program PT_DYNAMIC info.
+ */
+ regs->uregs[7] = infop->loadmap_addr;
+ if (infop->interpreter_loadmap_addr) {
+ /* Executable is dynamically loaded. */
+ regs->uregs[8] = infop->interpreter_loadmap_addr;
+ regs->uregs[9] = infop->interpreter_pt_dynamic_addr;
+ } else {
+ regs->uregs[8] = 0;
+ regs->uregs[9] = infop->pt_dynamic_addr;
+ }
+ }
}
#define ELF_NREG 18
@@ -1745,6 +1769,11 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
if (interp_info) {
interp_info->other_info = info;
sp = loader_build_fdpic_loadmap(interp_info, sp);
+ info->interpreter_loadmap_addr = interp_info->loadmap_addr;
+ info->interpreter_pt_dynamic_addr = interp_info->pt_dynamic_addr;
+ } else {
+ info->interpreter_loadmap_addr = 0;
+ info->interpreter_pt_dynamic_addr = 0;
}
}
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index da3b51724c..c55c8e294b 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -57,6 +57,8 @@ struct image_info {
uint16_t nsegs;
void *loadsegs;
abi_ulong pt_dynamic_addr;
+ abi_ulong interpreter_loadmap_addr;
+ abi_ulong interpreter_pt_dynamic_addr;
struct image_info *other_info;
};
@@ -183,6 +185,13 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
struct target_pt_regs * regs, struct image_info *infop,
struct linux_binprm *);
+/* Returns true if the image uses the FDPIC ABI. If this is the case,
+ * we have to provide some information (loadmap, pt_dynamic_info) such
+ * that the program can be relocated adequately. This is also useful
+ * when handling signals.
+ */
+int info_is_fdpic(struct image_info *info);
+
uint32_t get_elf_eflags(int fd);
int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);