All of lore.kernel.org
 help / color / mirror / Atom feed
* [Buildroot] [PATCH] package/uclibc: Fix SSP support for RISCV32
@ 2026-08-15 19:17 Waldemar Brodkorb
  2026-08-15 20:27 ` Romain Naour via buildroot
  0 siblings, 1 reply; 2+ messages in thread
From: Waldemar Brodkorb @ 2026-08-15 19:17 UTC (permalink / raw)
  To: buildroot

Add patch pending upstream to fix SSP for RISCV32.

Fixes:
  https://autobuild.buildroot.org/results/1b6/1b6f2161b11390b6545bddbc39b444401c718ebb/

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
---
 .../0001-Fix-SSP-support-for-riscv32.patch    | 174 ++++++++++++++++++
 1 file changed, 174 insertions(+)
 create mode 100644 package/uclibc/0001-Fix-SSP-support-for-riscv32.patch

diff --git a/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch b/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch
new file mode 100644
index 0000000000..b2e38726f5
--- /dev/null
+++ b/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch
@@ -0,0 +1,174 @@
+From c6efc293a52fdde7d4876243faaaa768fe052719 Mon Sep 17 00:00:00 2001
+From: Waldemar Brodkorb <wbx@openadk.org>
+Date: Sat, 15 Aug 2026 18:20:33 +0200
+Subject: [PATCH] Fix SSP support for riscv32
+
+On modern 32-bit architectures like RISC-V (riscv32), legacy 32-bit
+time syscalls like __NR_gettimeofday are intentionally omitted because
+RV32 implements a strict time64-only ABI to avoid the Year 2038 bug.
+
+Therefore, use AT_RANDOM from the auxiliary vector first, as glibc does,
+to obtain random data for the stack canary. If AT_RANDOM is unavailable,
+fall back to reading random data from /dev/urandom.
+
+Tested with aarch64, riscv32 and riscv32 noMMU targets.
+
+Upstream: https://mailman.openadk.org/mailman3/hyperkitty/list/devel@uclibc-ng.org/thread/WIKMWPXJYAPTVVZ2MMZINUJNPIJXBMOE/
+Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
+---
+ extra/Configs/Config.in               | 10 -------
+ ldso/include/dl-syscall.h             | 12 --------
+ ldso/ldso/ldso.c                      |  4 ++-
+ libc/misc/internals/__uClibc_main.c   |  4 ++-
+ libc/sysdeps/linux/common/dl-osinfo.h | 40 +++++++++++++++++----------
+ 5 files changed, 32 insertions(+), 38 deletions(-)
+
+diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
+index c3aabf1b4..15a072593 100644
+--- a/extra/Configs/Config.in
++++ b/extra/Configs/Config.in
+@@ -2211,16 +2211,6 @@ config UCLIBC_HAS_SSP
+ 
+ 	  Most people will answer N.
+ 
+-config SSP_QUICK_CANARY
+-	bool "Use simple guard values without accessing /dev/urandom"
+-	depends on UCLIBC_HAS_SSP
+-	help
+-	  Use gettimeofday(2) to define the __guard without accessing
+-	  /dev/urandom.
+-	  WARNING: This makes smashing stack protector vulnerable to timing
+-	  	attacks.
+-	  Most people will answer N.
+-
+ choice
+ 	prompt "Propolice protection blocking signal"
+ 	depends on UCLIBC_HAS_SSP
+diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h
+index c143b8d45..e08b2cd41 100644
+--- a/ldso/include/dl-syscall.h
++++ b/ldso/include/dl-syscall.h
+@@ -260,18 +260,6 @@ _dl_pread(int fd, void *buf, size_t count, off_t offset)
+ }
+ #endif
+ 
+-#ifdef __UCLIBC_HAS_SSP__
+-# include <sys/time.h>
+-# define __NR__dl_gettimeofday __NR_gettimeofday
+-static __always_inline _syscall2(int, _dl_gettimeofday, struct timeval *, tv,
+-# ifdef __USE_BSD
+-                        struct timezone *
+-# else
+-                        void *
+-# endif
+-						, tz)
+-#endif
+-
+ /* Some architectures always use 12 as page shift for mmap2() eventhough the
+  * real PAGE_SHIFT != 12.  Other architectures use the same value as
+  * PAGE_SHIFT...
+diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c
+index 55f7d7e45..96ee3d496 100755
+--- a/ldso/ldso/ldso.c
++++ b/ldso/ldso/ldso.c
+@@ -1225,7 +1225,9 @@ of this helper program; chances are you did not intend to run this program.\n\
+ #ifdef __UCLIBC_HAS_SSP__
+ 	_dl_debug_early("Setting up SSP guards\n");
+ 	/* Set up the stack checker's canary.  */
+-	stack_chk_guard = _dl_setup_stack_chk_guard ();
++	stack_chk_guard = _dl_setup_stack_chk_guard (
++		_dl_auxvt[AT_RANDOM].a_type == AT_RANDOM ?
++		(void *)_dl_auxvt[AT_RANDOM].a_un.a_val : NULL);
+ # ifdef THREAD_SET_STACK_GUARD
+ 	THREAD_SET_STACK_GUARD (stack_chk_guard);
+ # else
+diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c
+index 549606505..bbf471b17 100644
+--- a/libc/misc/internals/__uClibc_main.c
++++ b/libc/misc/internals/__uClibc_main.c
+@@ -296,7 +296,9 @@ void __uClibc_init(void)
+ #ifndef SHARED
+ # ifdef __UCLIBC_HAS_SSP__
+     /* Set up the stack checker's canary.  */
+-    stack_chk_guard = _dl_setup_stack_chk_guard();
++    stack_chk_guard = _dl_setup_stack_chk_guard(
++    _dl_auxvt[AT_RANDOM].a_type == AT_RANDOM ?
++        (void *)_dl_auxvt[AT_RANDOM].a_un.a_val : NULL);
+ #  ifdef THREAD_SET_STACK_GUARD
+     THREAD_SET_STACK_GUARD (stack_chk_guard);
+ #  else
+diff --git a/libc/sysdeps/linux/common/dl-osinfo.h b/libc/sysdeps/linux/common/dl-osinfo.h
+index 3110cb05d..0a42ea094 100644
+--- a/libc/sysdeps/linux/common/dl-osinfo.h
++++ b/libc/sysdeps/linux/common/dl-osinfo.h
+@@ -21,22 +21,42 @@
+ #  ifdef IS_IN_libc
+ #   include <fcntl.h>
+ #   include <unistd.h>
+-#   include <sys/time.h>
++#   include <string.h>
+ #   define OPEN open
+ #   define READ read
+ #   define CLOSE close
+-#   define GETTIMEOFDAY gettimeofday
++#   define MEMCPY memcpy
+ #  else
++#   include <dl-string.h>
+ #   define OPEN _dl_open
+ #   define READ _dl_read
+ #   define CLOSE _dl_close
+-#   define GETTIMEOFDAY _dl_gettimeofday
++#   define MEMCPY _dl_memcpy
+ #  endif
+ 
+-static __always_inline uintptr_t _dl_setup_stack_chk_guard(void)
++static __always_inline uintptr_t
++_dl_setup_stack_chk_guard(void *dl_random)
+ {
+ 	uintptr_t ret;
+-#  ifndef __SSP_QUICK_CANARY__
++
++	/*
++	 * Linux supplies random data through AT_RANDOM.
++	 * Use it directly when available.
++	 */
++	if (dl_random != NULL) {
++		MEMCPY(&ret, dl_random, sizeof(ret));
++
++#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
++		ret &= ~(uintptr_t)0xff;
++#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
++		ret &= ~((uintptr_t)0xff << (8 * (sizeof(ret) - 1)));
++#else
++# error "Unknown byte order"
++#endif
++
++		return ret;
++	}
++
+ 	{
+ 		int fd = OPEN("/dev/urandom", O_RDONLY, 0);
+ 		if (fd >= 0) {
+@@ -46,18 +66,10 @@ static __always_inline uintptr_t _dl_setup_stack_chk_guard(void)
+ 				return ret;
+ 		}
+ 	}
+-#  endif /* !__SSP_QUICK_CANARY__ */
+ 
+-	/* Start with the "terminator canary". */
++	/* Fallback just the "terminator canary". */
+ 	ret = 0xFF0A0D00UL;
+ 
+-	/* Everything failed? Or we are using a weakened model of the
+-	 * terminator canary */
+-	{
+-		struct timeval tv;
+-		if (GETTIMEOFDAY(&tv, NULL) != (-1))
+-			ret ^= tv.tv_usec ^ tv.tv_sec;
+-	}
+ 	return ret;
+ }
+ # endif /* libc || rtld */
+-- 
+2.47.3
+
-- 
2.47.3

_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot

^ permalink raw reply related	[flat|nested] 2+ messages in thread
* Re: [Buildroot] [PATCH] package/uclibc: Fix SSP support for RISCV32
  2026-08-15 19:17 [Buildroot] [PATCH] package/uclibc: Fix SSP support for RISCV32 Waldemar Brodkorb
@ 2026-08-15 20:27 ` Romain Naour via buildroot
  0 siblings, 0 replies; 2+ messages in thread
From: Romain Naour via buildroot @ 2026-08-15 20:27 UTC (permalink / raw)
  To: Waldemar Brodkorb, buildroot

Hello Waldemar, All,

Le 15/08/2026 à 21:17, Waldemar Brodkorb a écrit :
> Add patch pending upstream to fix SSP for RISCV32.
> 
> Fixes:
>   https://autobuild.buildroot.org/results/1b6/1b6f2161b11390b6545bddbc39b444401c718ebb/
> 

I tested the qemu_riscv32_virt_defconfig with uclibc-ng selected and SSP support
enabled.

Tested-by: Romain Naour <romain.naour@smile.fr>

Best regards,
Romain

> Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
> ---
>  .../0001-Fix-SSP-support-for-riscv32.patch    | 174 ++++++++++++++++++
>  1 file changed, 174 insertions(+)
>  create mode 100644 package/uclibc/0001-Fix-SSP-support-for-riscv32.patch
> 
> diff --git a/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch b/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch
> new file mode 100644
> index 0000000000..b2e38726f5
> --- /dev/null
> +++ b/package/uclibc/0001-Fix-SSP-support-for-riscv32.patch
> @@ -0,0 +1,174 @@
> +From c6efc293a52fdde7d4876243faaaa768fe052719 Mon Sep 17 00:00:00 2001
> +From: Waldemar Brodkorb <wbx@openadk.org>
> +Date: Sat, 15 Aug 2026 18:20:33 +0200
> +Subject: [PATCH] Fix SSP support for riscv32
> +
> +On modern 32-bit architectures like RISC-V (riscv32), legacy 32-bit
> +time syscalls like __NR_gettimeofday are intentionally omitted because
> +RV32 implements a strict time64-only ABI to avoid the Year 2038 bug.
> +
> +Therefore, use AT_RANDOM from the auxiliary vector first, as glibc does,
> +to obtain random data for the stack canary. If AT_RANDOM is unavailable,
> +fall back to reading random data from /dev/urandom.
> +
> +Tested with aarch64, riscv32 and riscv32 noMMU targets.
> +
> +Upstream: https://mailman.openadk.org/mailman3/hyperkitty/list/devel@uclibc-ng.org/thread/WIKMWPXJYAPTVVZ2MMZINUJNPIJXBMOE/
> +Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
> +---
> + extra/Configs/Config.in               | 10 -------
> + ldso/include/dl-syscall.h             | 12 --------
> + ldso/ldso/ldso.c                      |  4 ++-
> + libc/misc/internals/__uClibc_main.c   |  4 ++-
> + libc/sysdeps/linux/common/dl-osinfo.h | 40 +++++++++++++++++----------
> + 5 files changed, 32 insertions(+), 38 deletions(-)
> +
> +diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
> +index c3aabf1b4..15a072593 100644
> +--- a/extra/Configs/Config.in
> ++++ b/extra/Configs/Config.in
> +@@ -2211,16 +2211,6 @@ config UCLIBC_HAS_SSP
> + 
> + 	  Most people will answer N.
> + 
> +-config SSP_QUICK_CANARY
> +-	bool "Use simple guard values without accessing /dev/urandom"
> +-	depends on UCLIBC_HAS_SSP
> +-	help
> +-	  Use gettimeofday(2) to define the __guard without accessing
> +-	  /dev/urandom.
> +-	  WARNING: This makes smashing stack protector vulnerable to timing
> +-	  	attacks.
> +-	  Most people will answer N.
> +-
> + choice
> + 	prompt "Propolice protection blocking signal"
> + 	depends on UCLIBC_HAS_SSP
> +diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h
> +index c143b8d45..e08b2cd41 100644
> +--- a/ldso/include/dl-syscall.h
> ++++ b/ldso/include/dl-syscall.h
> +@@ -260,18 +260,6 @@ _dl_pread(int fd, void *buf, size_t count, off_t offset)
> + }
> + #endif
> + 
> +-#ifdef __UCLIBC_HAS_SSP__
> +-# include <sys/time.h>
> +-# define __NR__dl_gettimeofday __NR_gettimeofday
> +-static __always_inline _syscall2(int, _dl_gettimeofday, struct timeval *, tv,
> +-# ifdef __USE_BSD
> +-                        struct timezone *
> +-# else
> +-                        void *
> +-# endif
> +-						, tz)
> +-#endif
> +-
> + /* Some architectures always use 12 as page shift for mmap2() eventhough the
> +  * real PAGE_SHIFT != 12.  Other architectures use the same value as
> +  * PAGE_SHIFT...
> +diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c
> +index 55f7d7e45..96ee3d496 100755
> +--- a/ldso/ldso/ldso.c
> ++++ b/ldso/ldso/ldso.c
> +@@ -1225,7 +1225,9 @@ of this helper program; chances are you did not intend to run this program.\n\
> + #ifdef __UCLIBC_HAS_SSP__
> + 	_dl_debug_early("Setting up SSP guards\n");
> + 	/* Set up the stack checker's canary.  */
> +-	stack_chk_guard = _dl_setup_stack_chk_guard ();
> ++	stack_chk_guard = _dl_setup_stack_chk_guard (
> ++		_dl_auxvt[AT_RANDOM].a_type == AT_RANDOM ?
> ++		(void *)_dl_auxvt[AT_RANDOM].a_un.a_val : NULL);
> + # ifdef THREAD_SET_STACK_GUARD
> + 	THREAD_SET_STACK_GUARD (stack_chk_guard);
> + # else
> +diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c
> +index 549606505..bbf471b17 100644
> +--- a/libc/misc/internals/__uClibc_main.c
> ++++ b/libc/misc/internals/__uClibc_main.c
> +@@ -296,7 +296,9 @@ void __uClibc_init(void)
> + #ifndef SHARED
> + # ifdef __UCLIBC_HAS_SSP__
> +     /* Set up the stack checker's canary.  */
> +-    stack_chk_guard = _dl_setup_stack_chk_guard();
> ++    stack_chk_guard = _dl_setup_stack_chk_guard(
> ++    _dl_auxvt[AT_RANDOM].a_type == AT_RANDOM ?
> ++        (void *)_dl_auxvt[AT_RANDOM].a_un.a_val : NULL);
> + #  ifdef THREAD_SET_STACK_GUARD
> +     THREAD_SET_STACK_GUARD (stack_chk_guard);
> + #  else
> +diff --git a/libc/sysdeps/linux/common/dl-osinfo.h b/libc/sysdeps/linux/common/dl-osinfo.h
> +index 3110cb05d..0a42ea094 100644
> +--- a/libc/sysdeps/linux/common/dl-osinfo.h
> ++++ b/libc/sysdeps/linux/common/dl-osinfo.h
> +@@ -21,22 +21,42 @@
> + #  ifdef IS_IN_libc
> + #   include <fcntl.h>
> + #   include <unistd.h>
> +-#   include <sys/time.h>
> ++#   include <string.h>
> + #   define OPEN open
> + #   define READ read
> + #   define CLOSE close
> +-#   define GETTIMEOFDAY gettimeofday
> ++#   define MEMCPY memcpy
> + #  else
> ++#   include <dl-string.h>
> + #   define OPEN _dl_open
> + #   define READ _dl_read
> + #   define CLOSE _dl_close
> +-#   define GETTIMEOFDAY _dl_gettimeofday
> ++#   define MEMCPY _dl_memcpy
> + #  endif
> + 
> +-static __always_inline uintptr_t _dl_setup_stack_chk_guard(void)
> ++static __always_inline uintptr_t
> ++_dl_setup_stack_chk_guard(void *dl_random)
> + {
> + 	uintptr_t ret;
> +-#  ifndef __SSP_QUICK_CANARY__
> ++
> ++	/*
> ++	 * Linux supplies random data through AT_RANDOM.
> ++	 * Use it directly when available.
> ++	 */
> ++	if (dl_random != NULL) {
> ++		MEMCPY(&ret, dl_random, sizeof(ret));
> ++
> ++#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
> ++		ret &= ~(uintptr_t)0xff;
> ++#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
> ++		ret &= ~((uintptr_t)0xff << (8 * (sizeof(ret) - 1)));
> ++#else
> ++# error "Unknown byte order"
> ++#endif
> ++
> ++		return ret;
> ++	}
> ++
> + 	{
> + 		int fd = OPEN("/dev/urandom", O_RDONLY, 0);
> + 		if (fd >= 0) {
> +@@ -46,18 +66,10 @@ static __always_inline uintptr_t _dl_setup_stack_chk_guard(void)
> + 				return ret;
> + 		}
> + 	}
> +-#  endif /* !__SSP_QUICK_CANARY__ */
> + 
> +-	/* Start with the "terminator canary". */
> ++	/* Fallback just the "terminator canary". */
> + 	ret = 0xFF0A0D00UL;
> + 
> +-	/* Everything failed? Or we are using a weakened model of the
> +-	 * terminator canary */
> +-	{
> +-		struct timeval tv;
> +-		if (GETTIMEOFDAY(&tv, NULL) != (-1))
> +-			ret ^= tv.tv_usec ^ tv.tv_sec;
> +-	}
> + 	return ret;
> + }
> + # endif /* libc || rtld */
> +-- 
> +2.47.3
> +

_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-08-15 20:27 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-15 19:17 [Buildroot] [PATCH] package/uclibc: Fix SSP support for RISCV32 Waldemar Brodkorb
2026-08-15 20:27 ` Romain Naour via buildroot

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.