From fb799447ae2974a07907906dff5bd4b9e47b7123 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 1 Mar 2023 07:13:12 -0800 Subject: x86,objtool: Split UNWIND_HINT_EMPTY in two Mark reported that the ORC unwinder incorrectly marks an unwind as reliable when the unwind terminates prematurely in the dark corners of return_to_handler() due to lack of information about the next frame. The problem is UNWIND_HINT_EMPTY is used in two different situations: 1) The end of the kernel stack unwind before hitting user entry, boot code, or fork entry 2) A blind spot in ORC coverage where the unwinder has to bail due to lack of information about the next frame The ORC unwinder has no way to tell the difference between the two. When it encounters an undefined stack state with 'end=1', it blindly marks the stack reliable, which can break the livepatch consistency model. Fix it by splitting UNWIND_HINT_EMPTY into UNWIND_HINT_UNDEFINED and UNWIND_HINT_END_OF_STACK. Reported-by: Mark Rutland Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Acked-by: Steven Rostedt (Google) Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/fd6212c8b450d3564b855e1cb48404d6277b4d9f.1677683419.git.jpoimboe@kernel.org --- scripts/sorttable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/sorttable.h b/scripts/sorttable.h index deb7c1d3e979..7bd0184380d3 100644 --- a/scripts/sorttable.h +++ b/scripts/sorttable.h @@ -128,7 +128,7 @@ static int orc_sort_cmp(const void *_a, const void *_b) * whitelisted .o files which didn't get objtool generation. */ orc_a = g_orc_table + (a - g_orc_ip_table); - return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1; + return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1; } static void *sort_orctable(void *arg) -- cgit v1.2.3-59-g8ed1b From 27d000d635ce48b579988e9b3240352a2a0306e0 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 12 Apr 2023 12:03:16 -0700 Subject: scripts/objdump-func: Support multiple functions Allow specifying multiple functions on the cmdline. Note this removes the secret EXTRA_ARGS feature. While at it, spread out the awk to make it more readable. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/0bf5f4f5978660985037b24c6db49b114374eb4d.1681325924.git.jpoimboe@kernel.org --- scripts/objdump-func | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) (limited to 'scripts') diff --git a/scripts/objdump-func b/scripts/objdump-func index 4eb463dd9f52..7b15b873d0e2 100755 --- a/scripts/objdump-func +++ b/scripts/objdump-func @@ -3,7 +3,7 @@ # # Disassemble a single function. # -# usage: objdump-func +# usage: objdump-func [ ...] set -o errexit set -o nounset @@ -13,17 +13,33 @@ OBJDUMP="${CROSS_COMPILE:-}objdump" command -v gawk >/dev/null 2>&1 || die "gawk isn't installed" usage() { - echo "usage: objdump-func " >&2 + echo "usage: objdump-func [ ...]" >&2 exit 1 } [[ $# -lt 2 ]] && usage OBJ=$1; shift -FUNC=$1; shift - -# Secret feature to allow adding extra objdump args at the end -EXTRA_ARGS=$@ - -# Note this also matches compiler-added suffixes like ".cold", etc -${OBJDUMP} -wdr $EXTRA_ARGS $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' +FUNCS=("$@") + +${OBJDUMP} -wdr $OBJ | gawk -M -v _funcs="${FUNCS[*]}" ' + BEGIN { split(_funcs, funcs); } + /^$/ { func_match=0; } + /<.*>:/ { + f = gensub(/.*<(.*)>:/, "\\1", 1); + for (i in funcs) { + # match compiler-added suffixes like ".cold", etc + if (f ~ "^" funcs[i] "(\\..*)?") { + func_match = 1; + base = strtonum("0x" $1); + break; + } + } + } + { + if (func_match) { + addr = strtonum("0x" $1); + printf("%04x ", addr - base); + print; + } + }' -- cgit v1.2.3-59-g8ed1b