The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 698222457465ce343443be81c5512edda86e5914 Mon Sep 17 00:00:00 2001

From: Al Viro viro@zeniv.linux.org.uk Date: Thu, 24 Dec 2020 19:44:38 +0000 Subject: [PATCH] MIPS: Fix malformed NT_FILE and NT_SIGINFO in 32bit coredumps

Patches that introduced NT_FILE and NT_SIGINFO notes back in 2012 had taken care of native (fs/binfmt_elf.c) and compat (fs/compat_binfmt_elf.c) coredumps; unfortunately, compat on mips (which does not go through the usual compat_binfmt_elf.c) had not been noticed.

As the result, both N32 and O32 coredumps on 64bit mips kernels have those sections malformed enough to confuse the living hell out of all gdb and readelf versions (up to and including the tip of binutils-gdb.git).

Longer term solution is to make both O32 and N32 compat use the regular compat_binfmt_elf.c, but that's too much for backports. The minimal solution is to do in arch/mips/kernel/binfmt_elf[on]32.c the same thing those patches have done in fs/compat_binfmt_elf.c

Cc: stable@kernel.org # v3.7+ Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de

diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c index 6ee3f7218c67..c4441416e96b 100644 --- a/arch/mips/kernel/binfmt_elfn32.c +++ b/arch/mips/kernel/binfmt_elfn32.c @@ -103,4 +103,11 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value) #undef ns_to_kernel_old_timeval #define ns_to_kernel_old_timeval ns_to_old_timeval32

+/* + * Some data types as stored in coredump. + */ +#define user_long_t compat_long_t +#define user_siginfo_t compat_siginfo_t +#define copy_siginfo_to_external copy_siginfo_to_external32 + #include "../../../fs/binfmt_elf.c" diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c index 6dd103d3cebb..7b2a23f48c1a 100644 --- a/arch/mips/kernel/binfmt_elfo32.c +++ b/arch/mips/kernel/binfmt_elfo32.c @@ -106,4 +106,11 @@ jiffies_to_old_timeval32(unsigned long jiffies, struct old_timeval32 *value) #undef ns_to_kernel_old_timeval #define ns_to_kernel_old_timeval ns_to_old_timeval32

+/* + * Some data types as stored in coredump. + */ +#define user_long_t compat_long_t +#define user_siginfo_t compat_siginfo_t +#define copy_siginfo_to_external copy_siginfo_to_external32 + #include "../../../fs/binfmt_elf.c"