diff options
| author | Igor Ostapenko <pm@igoro.pro> | 2023-10-03 16:48:00 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2023-10-03 17:07:41 +0000 |
| commit | b4db386f9fa7be9668aa09d14b0bbd048a7a7e89 (patch) | |
| tree | 26b048a365461f4d7082e3f34cd49b1ba897e6c6 | |
| parent | 4862e8ac0223d7b19c8b3e070af1e2b38b18f333 (diff) | |
dtrace: fix fbt regression for aarch64
fbt computes incorrect instruction position for AArch64 kernel module symbol.
The issue is with the for loop, it does an extra increment of instr pointer
after the required instruction is found. Hence, a wrong instruction is
targeted for patching.
Signed-off-by: Igor Ostapenko <pm@igoro.pro>
Fixes: 980746e5cb26 ("fbt: simplify arm64 function-prologue parsing")
Reviewed by: markj
Pull Request: https://github.com/freebsd/freebsd-src/pull/855
MFC after: 1 week
| -rw-r--r-- | sys/cddl/dev/fbt/aarch64/fbt_isa.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/sys/cddl/dev/fbt/aarch64/fbt_isa.c b/sys/cddl/dev/fbt/aarch64/fbt_isa.c index 4094ea43a9fe..44690b97f77a 100644 --- a/sys/cddl/dev/fbt/aarch64/fbt_isa.c +++ b/sys/cddl/dev/fbt/aarch64/fbt_isa.c @@ -90,7 +90,6 @@ fbt_provide_module_function(linker_file_t lf, int symindx, uint32_t *instr, *limit; const char *name; char *modname; - bool found; int offs; modname = opaque; @@ -119,16 +118,16 @@ fbt_provide_module_function(linker_file_t lf, int symindx, if ((*instr & BTI_MASK) == BTI_INSTR) instr++; - /* Look for stp (pre-indexed) operation */ - found = false; /* * If the first instruction is a nop it's a specially marked * asm function. We only support a nop first as it's not a normal * part of the function prologue. */ if (*instr == NOP_INSTR) - found = true; - for (; !found && instr < limit; instr++) { + goto found; + + /* Look for stp (pre-indexed) or sub operation */ + for (; instr < limit; instr++) { /* * Functions start with "stp xt1, xt2, [xn, <const>]!" or * "sub sp, sp, <const>". @@ -142,14 +141,14 @@ fbt_provide_module_function(linker_file_t lf, int symindx, * past the function prologue. */ if (((*instr >> ADDR_SHIFT) & ADDR_MASK) == 31) - found = true; + break; } else if ((*instr & SUB_MASK) == SUB_INSTR && ((*instr >> SUB_RD_SHIFT) & SUB_R_MASK) == 31 && ((*instr >> SUB_RN_SHIFT) & SUB_R_MASK) == 31) - found = true; + break; } - - if (!found) +found: + if (instr >= limit) return (0); fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); |