diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-10-28 14:24:03 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-29 22:49:29 +1100 |
| commit | c93d4f6ecf4b0699d0f2088f7bd9cd09af45d65a (patch) | |
| tree | f68a4ab7358760ea588b5686c5f8b701bf14c048 /arch/powerpc/kernel/trace/ftrace.c | |
| parent | 88670fdb26800228606c078ba4a018e9522a75a8 (diff) | |
powerpc/ftrace: Add module_trampoline_target() for PPC32
module_trampoline_target() is used by __ftrace_modify_call().
Implement it for PPC32 so that CONFIG_DYNAMIC_FTRACE_WITH_REGS
can be activated on PPC32 as well.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel/trace/ftrace.c')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 37 |
1 files changed, 4 insertions, 33 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index d89c5df4f206..c1d54c18e912 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -222,9 +222,8 @@ __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { struct ppc_inst op; - unsigned int jmp[4]; unsigned long ip = rec->ip; - unsigned long tramp; + unsigned long tramp, ptr; if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE)) return -EFAULT; @@ -238,41 +237,13 @@ __ftrace_make_nop(struct module *mod, /* lets find where the pointer goes */ tramp = find_bl_target(ip, op); - /* - * On PPC32 the trampoline looks like: - * 0x3d, 0x80, 0x00, 0x00 lis r12,sym@ha - * 0x39, 0x8c, 0x00, 0x00 addi r12,r12,sym@l - * 0x7d, 0x89, 0x03, 0xa6 mtctr r12 - * 0x4e, 0x80, 0x04, 0x20 bctr - */ - - pr_devel("ip:%lx jumps to %lx", ip, tramp); - /* Find where the trampoline jumps to */ - if (copy_from_kernel_nofault(jmp, (void *)tramp, sizeof(jmp))) { - pr_err("Failed to read %lx\n", tramp); + if (module_trampoline_target(mod, tramp, &ptr)) { + pr_err("Failed to get trampoline target\n"); return -EFAULT; } - pr_devel(" %08x %08x ", jmp[0], jmp[1]); - - /* verify that this is what we expect it to be */ - if (((jmp[0] & 0xffff0000) != 0x3d800000) || - ((jmp[1] & 0xffff0000) != 0x398c0000) || - (jmp[2] != 0x7d8903a6) || - (jmp[3] != 0x4e800420)) { - pr_err("Not a trampoline\n"); - return -EINVAL; - } - - tramp = (jmp[1] & 0xffff) | - ((jmp[0] & 0xffff) << 16); - if (tramp & 0x8000) - tramp -= 0x10000; - - pr_devel(" %lx ", tramp); - - if (tramp != addr) { + if (ptr != addr) { pr_err("Trampoline location %08lx does not match addr\n", tramp); return -EINVAL; |