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[PATCH v6 05/19] linux-user: Use ImageSource in load_symbols
From: |
Richard Henderson |
Subject: |
[PATCH v6 05/19] linux-user: Use ImageSource in load_symbols |
Date: |
Fri, 29 Sep 2023 19:15:15 -0700 |
Aside from the section headers, we're unlikely to hit the
ImageSource cache on guest executables. But the interface
for imgsrc_read_* is better.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/elfload.c | 87 ++++++++++++++++++++++++--------------------
1 file changed, 48 insertions(+), 39 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index d6f1b8d2b1..ed276edb3c 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2193,7 +2193,8 @@ static inline void
bswap_mips_abiflags(Mips_elf_abiflags_v0 *abiflags) { }
#ifdef USE_ELF_CORE_DUMP
static int elf_core_dump(int, const CPUArchState *);
#endif /* USE_ELF_CORE_DUMP */
-static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias);
+static void load_symbols(struct elfhdr *hdr, const ImageSource *src,
+ abi_ulong load_bias);
/* Verify the portions of EHDR within E_IDENT for the target.
This can be performed before bswapping the entire header. */
@@ -3438,7 +3439,7 @@ static void load_elf_image(const char *image_name, const
ImageSource *src,
}
if (qemu_log_enabled()) {
- load_symbols(ehdr, src->fd, load_bias);
+ load_symbols(ehdr, src, load_bias);
}
debuginfo_report_elf(image_name, src->fd, load_bias);
@@ -3529,19 +3530,20 @@ static int symcmp(const void *s0, const void *s1)
}
/* Best attempt to load symbols from this ELF object. */
-static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias)
+static void load_symbols(struct elfhdr *hdr, const ImageSource *src,
+ abi_ulong load_bias)
{
int i, shnum, nsyms, sym_idx = 0, str_idx = 0;
- uint64_t segsz;
- struct elf_shdr *shdr;
+ g_autofree struct elf_shdr *shdr = NULL;
char *strings = NULL;
- struct syminfo *s = NULL;
- struct elf_sym *new_syms, *syms = NULL;
+ struct elf_sym *syms = NULL;
+ struct elf_sym *new_syms;
+ uint64_t segsz;
shnum = hdr->e_shnum;
- i = shnum * sizeof(struct elf_shdr);
- shdr = (struct elf_shdr *)alloca(i);
- if (pread(fd, shdr, i, hdr->e_shoff) != i) {
+ shdr = imgsrc_read_alloc(hdr->e_shoff, shnum * sizeof(struct elf_shdr),
+ src, NULL);
+ if (shdr == NULL) {
return;
}
@@ -3559,31 +3561,33 @@ static void load_symbols(struct elfhdr *hdr, int fd,
abi_ulong load_bias)
found:
/* Now know where the strtab and symtab are. Snarf them. */
- s = g_try_new(struct syminfo, 1);
- if (!s) {
- goto give_up;
- }
segsz = shdr[str_idx].sh_size;
- s->disas_strtab = strings = g_try_malloc(segsz);
- if (!strings ||
- pread(fd, strings, segsz, shdr[str_idx].sh_offset) != segsz) {
+ strings = g_try_malloc(segsz);
+ if (!strings) {
+ goto give_up;
+ }
+ if (!imgsrc_read(strings, shdr[str_idx].sh_offset, segsz, src, NULL)) {
goto give_up;
}
segsz = shdr[sym_idx].sh_size;
- syms = g_try_malloc(segsz);
- if (!syms || pread(fd, syms, segsz, shdr[sym_idx].sh_offset) != segsz) {
- goto give_up;
- }
-
if (segsz / sizeof(struct elf_sym) > INT_MAX) {
- /* Implausibly large symbol table: give up rather than ploughing
- * on with the number of symbols calculation overflowing
+ /*
+ * Implausibly large symbol table: give up rather than ploughing
+ * on with the number of symbols calculation overflowing.
*/
goto give_up;
}
nsyms = segsz / sizeof(struct elf_sym);
+ syms = g_try_malloc(segsz);
+ if (!syms) {
+ goto give_up;
+ }
+ if (!imgsrc_read(syms, shdr[sym_idx].sh_offset, segsz, src, NULL)) {
+ goto give_up;
+ }
+
for (i = 0; i < nsyms; ) {
bswap_sym(syms + i);
/* Throw away entries which we do not need. */
@@ -3608,10 +3612,12 @@ static void load_symbols(struct elfhdr *hdr, int fd,
abi_ulong load_bias)
goto give_up;
}
- /* Attempt to free the storage associated with the local symbols
- that we threw away. Whether or not this has any effect on the
- memory allocation depends on the malloc implementation and how
- many symbols we managed to discard. */
+ /*
+ * Attempt to free the storage associated with the local symbols
+ * that we threw away. Whether or not this has any effect on the
+ * memory allocation depends on the malloc implementation and how
+ * many symbols we managed to discard.
+ */
new_syms = g_try_renew(struct elf_sym, syms, nsyms);
if (new_syms == NULL) {
goto give_up;
@@ -3620,20 +3626,23 @@ static void load_symbols(struct elfhdr *hdr, int fd,
abi_ulong load_bias)
qsort(syms, nsyms, sizeof(*syms), symcmp);
- s->disas_num_syms = nsyms;
-#if ELF_CLASS == ELFCLASS32
- s->disas_symtab.elf32 = syms;
-#else
- s->disas_symtab.elf64 = syms;
-#endif
- s->lookup_symbol = lookup_symbolxx;
- s->next = syminfos;
- syminfos = s;
+ {
+ struct syminfo *s = g_new(struct syminfo, 1);
+ s->disas_strtab = strings;
+ s->disas_num_syms = nsyms;
+#if ELF_CLASS == ELFCLASS32
+ s->disas_symtab.elf32 = syms;
+#else
+ s->disas_symtab.elf64 = syms;
+#endif
+ s->lookup_symbol = lookup_symbolxx;
+ s->next = syminfos;
+ syminfos = s;
+ }
return;
-give_up:
- g_free(s);
+ give_up:
g_free(strings);
g_free(syms);
}
--
2.34.1
- [PATCH v6 00/19] linux-user: Implement VDSOs, Richard Henderson, 2023/09/29
- [PATCH v6 01/19] linux-user: Introduce imgsrc_read, imgsrc_read_alloc, Richard Henderson, 2023/09/29
- [PATCH v6 04/19] linux-user: Use ImageSource in load_elf_image, Richard Henderson, 2023/09/29
- [PATCH v6 05/19] linux-user: Use ImageSource in load_symbols,
Richard Henderson <=
- [PATCH v6 03/19] linux-user: Do not clobber bprm_buf swapping ehdr, Richard Henderson, 2023/09/29
- [PATCH v6 02/19] linux-user: Tidy loader_exec, Richard Henderson, 2023/09/29
- [PATCH v6 07/19] linux-user: Load vdso image if available, Richard Henderson, 2023/09/29
- [PATCH v6 13/19] linux-user/hppa: Add vdso, Richard Henderson, 2023/09/29
- [PATCH v6 12/19] linux-user/arm: Add vdso, Richard Henderson, 2023/09/29
- [PATCH v6 06/19] linux-user: Replace bprm->fd with bprm->src.fd, Richard Henderson, 2023/09/29
- [PATCH v6 18/19] linux-user/s390x: Add vdso, Richard Henderson, 2023/09/29
- [PATCH v6 10/19] linux-user/x86_64: Add vdso, Richard Henderson, 2023/09/29
- [PATCH v6 16/19] linux-user/ppc: Add vdso, Richard Henderson, 2023/09/29
- [PATCH v6 17/19] linux-user/s390x: Rename __SIGNAL_FRAMESIZE to STACK_FRAME_OVERHEAD, Richard Henderson, 2023/09/29