main/musl: add relro support

ref #2614

main/musl/1003-implement-PT_GNU_RELRO-support.patch

+From 2946056f1963aeb161568a7a8aea5b7bb9fb1edd Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
+Date: Tue, 25 Mar 2014 14:13:27 +0200
+Subject: [PATCH 1/1] implement PT_GNU_RELRO support
+
+---
+ src/ldso/dynlink.c | 48 +++++++++++++++++++++++++++++++++++-------------
+ 1 file changed, 35 insertions(+), 13 deletions(-)
+
+diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
+index 616dc3e..b903e97 100644
+--- a/src/ldso/dynlink.c
++++ b/src/ldso/dynlink.c
+@@ -74,6 +74,7 @@ struct dso {
+ 	char *rpath_orig, *rpath;
+ 	void *tls_image;
+ 	size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
++	size_t relro_start, relro_end;
+ 	void **new_dtv;
+ 	unsigned char *new_tls;
+ 	int new_dtv_idx, new_tls_idx;
+@@ -281,27 +282,29 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
+  * and "donate" them to the heap by setting up minimal malloc
+  * structures and then freeing them. */
+ 
+-static void reclaim(unsigned char *base, size_t start, size_t end)
++static void reclaim(struct dso *dso, size_t start, size_t end)
+ {
+ 	size_t *a, *z;
++	if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
++	if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
+ 	start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
+ 	end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
+ 	if (start>end || end-start < 4*sizeof(size_t)) return;
+-	a = (size_t *)(base + start);
+-	z = (size_t *)(base + end);
++	a = (size_t *)(dso->base + start);
++	z = (size_t *)(dso->base + end);
+ 	a[-2] = 1;
+ 	a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
+ 	z[1] = 1;
+ 	free(a);
+ }
+ 
+-static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt)
++static void reclaim_gaps(struct dso *dso, Phdr *ph, size_t phent, size_t phcnt)
+ {
+ 	for (; phcnt--; ph=(void *)((char *)ph+phent)) {
+ 		if (ph->p_type!=PT_LOAD) continue;
+ 		if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
+-		reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
+-		reclaim(base, ph->p_vaddr+ph->p_memsz,
++		reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
++		reclaim(dso, ph->p_vaddr+ph->p_memsz,
+ 			ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
+ 	}
+ }
+@@ -346,11 +349,14 @@ static void *map_library(int fd, struct dso *dso)
+ 	for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
+ 		if (ph->p_type == PT_DYNAMIC)
+ 			dyn = ph->p_vaddr;
+-		if (ph->p_type == PT_TLS) {
++		else if (ph->p_type == PT_TLS) {
+ 			tls_image = ph->p_vaddr;
+ 			dso->tls_align = ph->p_align;
+ 			dso->tls_len = ph->p_filesz;
+ 			dso->tls_size = ph->p_memsz;
++		} else if (ph->p_type == PT_GNU_RELRO) {
++			dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
++			dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
+ 		}
+ 		if (ph->p_type != PT_LOAD) continue;
+ 		if (ph->p_vaddr < addr_min) {
+@@ -419,12 +425,12 @@ static void *map_library(int fd, struct dso *dso)
+ 				goto error;
+ 			break;
+ 		}
+-	if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
+ 	dso->map = map;
+ 	dso->map_len = map_len;
+ 	dso->base = base;
+ 	dso->dynv = (void *)(base+dyn);
+ 	if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
++	if (!runtime) reclaim_gaps(dso, ph0, eh->e_phentsize, eh->e_phnum);
+ 	free(allocated_buf);
+ 	return map;
+ noexec:
+@@ -766,6 +772,17 @@ static void reloc_all(struct dso *p)
+ 			2+(dyn[DT_PLTREL]==DT_RELA));
+ 		do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
+ 		do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
++
++		if (p->relro_start != p->relro_end &&
++		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
++			snprintf(errbuf, sizeof errbuf,
++				"Error relocating %s: RELRO protection failed",
++				p->name);
++			if (runtime) longjmp(*rtld_fail, 1);
++			dprintf(2, "%s\n", errbuf);
++			ldso_fail = 1;
++		}
++
+ 		p->relocated = 1;
+ 	}
+ }
+@@ -1027,6 +1044,9 @@ void *__dynlink(int argc, char **argv)
+ 				app->tls_len = phdr->p_filesz;
+ 				app->tls_size = phdr->p_memsz;
+ 				app->tls_align = phdr->p_align;
++			} else if (phdr->p_type == PT_GNU_RELRO) {
++				app->relro_start = phdr->p_vaddr & -PAGE_SIZE;
++				app->relro_end = (phdr->p_vaddr + phdr->p_memsz) & -PAGE_SIZE;
+ 			}
+ 		}
+ 		if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
+@@ -1133,9 +1153,9 @@ void *__dynlink(int argc, char **argv)
+ 	/* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
+ 
+ 	/* Donate unused parts of app and library mapping to malloc */
+-	reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
++	reclaim_gaps(app, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
+ 	ehdr = (void *)lib->base;
+-	reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
++	reclaim_gaps(lib, (void *)(lib->base+ehdr->e_phoff),
+ 		ehdr->e_phentsize, ehdr->e_phnum);
+ 
+ 	/* Load preload/needed libraries, add their symbols to the global
+@@ -1175,9 +1195,11 @@ void *__dynlink(int argc, char **argv)
+ 	runtime = 1;
+ 
+ #ifndef DYNAMIC_IS_RO
+-	for (i=0; app->dynv[i]; i+=2)
+-		if (app->dynv[i]==DT_DEBUG)
+-			app->dynv[i+1] = (size_t)&debug;
++	if (app->relro_start == app->relro_end) {
++		for (i=0; app->dynv[i]; i+=2)
++			if (app->dynv[i]==DT_DEBUG)
++				app->dynv[i+1] = (size_t)&debug;
++	}
+ #endif
+ 	debug.ver = 1;
+ 	debug.bp = _dl_debug_state;
+-- 
+1.9.0
+

main/musl/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Timo Teräs <timo.teras@iki.fi>
 pkgname=musl
 pkgver=1.0.0
-pkgrel=0
+pkgrel=1
 pkgdesc="the musl c library (libc) implementation"
 url="http://www.musl-libc.org/"
 arch="all"
@@ -16,6 +16,7 @@ subpackages="$pkgname-dev $pkgname-utils"
 source="http://www.musl-libc.org/releases/musl-$pkgver.tar.gz
 	1001-add-basic-dns-record-parsing-functions.patch
 	1002-fix-confstr-return-value.patch
+	1003-implement-PT_GNU_RELRO-support.patch
 	2001-workaround-gcc-pr58245.patch
 
 	getopt_long.c
@@ -115,6 +116,7 @@ crosstool() {
 md5sums="e54664fdf211d27737e328c4462b545e  musl-1.0.0.tar.gz
 a3810683ef61ac27e2f6ec9801280c81  1001-add-basic-dns-record-parsing-functions.patch
 499bced87843940199898d1508ef58df  1002-fix-confstr-return-value.patch
+82bdbdb20210ca6e19dbd7da6b54e2e6  1003-implement-PT_GNU_RELRO-support.patch
 7a09c5cd7b3e9532e6902f54a5e928bb  2001-workaround-gcc-pr58245.patch
 61c6c1e84ed1df82abbe6d75e90cf21c  getopt_long.c
 0df687757221bbb0fc1aa67f1bd646f9  __stack_chk_fail_local.c
@@ -124,6 +126,7 @@ ef81489a6258501cf45db58dfc6d5211  getent
 sha256sums="1ad7f45d2972daff19c9e6a92714e6d70f4aad003cd8c3d1e6113432114c1a32  musl-1.0.0.tar.gz
 758390768b1bc4159d56908ca332b9640cd0552ed3b4b2b8d4a6d499c54c11a1  1001-add-basic-dns-record-parsing-functions.patch
 dba7e5155efab40829ec0202f1135942004e8e79cff287cbb455355a0d67705f  1002-fix-confstr-return-value.patch
+ad4cf7c3d778514daaf3ad2de5939900214522387c7904a246b2892efe87c3d0  1003-implement-PT_GNU_RELRO-support.patch
 45d6efda7450809e4e68f6e951431dcadf6cb7f0260930d50a9f1a8667aca49f  2001-workaround-gcc-pr58245.patch
 d9b644ec20bc33e81a7c52b9fcf7973d835923a69faf50f03db45534b811bd96  getopt_long.c
 299a7d75a09de3e2e11e7fb4acc3182e4a14e868093d2f30938fce9bfcff13da  __stack_chk_fail_local.c
@@ -133,6 +136,7 @@ d6996273f5aaaed429058257e4646b243d9e3a4d8609522f802762453f5be4cb  getent
 sha512sums="c76cbfe60cbe9b1ceb1faedddf2dcce0f11c942c8f74e4f217efe63e8e1d7be70fcb6cf1182eeaee90441152c4493d678682cb247a0dbc7537d24f943a7bbdf8  musl-1.0.0.tar.gz
 dad965258daf69371b844f76bfe5a914b0eca0ca76f3fc340b8fd7acf598b5f87bbe6d68b1f43ed0293ee0ed3bfd85d5173ccc169aa6265646248d5b8a906708  1001-add-basic-dns-record-parsing-functions.patch
 d4c5f3c5a8ab3a9f1f63a22933bf4dcc67d6aff630066c9e3bb0edf9f46ab8b6e228ded906e4f82b7849d3b7e84ca25c9322bf5c5787fca10203482a38176700  1002-fix-confstr-return-value.patch
+5199c16d12a46dd990005ad0d2bc4c49e978db440be92cf8e1f848d6a74dcb5e789052c17088bbeac6540365f02fda1603b156c3346f89132f71122f384d734e  1003-implement-PT_GNU_RELRO-support.patch
 69ad3fc851b44f33dd7c98b83fd0adbd149b37263d17b989f4d7338ee0703dfe8994f4299744e2509492300227d652de6f21b6cdba9b633fcefd3d9f7ca0cf20  2001-workaround-gcc-pr58245.patch
 140f3f20d30bd95ebce8c41b8cc7f616c6cbedf4ea06c729c21014e74f6043796825cc40ebc5180620ea38173afdba23f09ebf6d8b11fa05440b14d23764fca9  getopt_long.c
 062bb49fa54839010acd4af113e20f7263dde1c8a2ca359b5fb2661ef9ed9d84a0f7c3bc10c25dcfa10bb3c5a4874588dff636ac43d5dbb3d748d75400756d0b  __stack_chk_fail_local.c