| Message ID | ZeABDXA82kA3UvEJ@mars.tail36e24.ts.net |
|---|---|
| State | New |
| Headers | show |
| Series | Hurd x86_64: add unwind support for signal trampoline code | expand |
Flavio Cruz, le mer. 28 févr. 2024 22:59:09 -0500, a ecrit: > Tested with some simple toy examples where an exception is thrown in the > signal handler. > > libgcc/ChangeLog: > * config/i386/gnu-unwind.h: Support unwinding x86_64 signal frames. > > Signed-off-by: Flavio Cruz <flaviocruz@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Thanks!! > --- > libgcc/config/i386/gnu-unwind.h | 97 ++++++++++++++++++++++++++++++++- > 1 file changed, 94 insertions(+), 3 deletions(-) > > diff --git a/libgcc/config/i386/gnu-unwind.h b/libgcc/config/i386/gnu-unwind.h > index 0751b5593d4..02b060ab4a5 100644 > --- a/libgcc/config/i386/gnu-unwind.h > +++ b/libgcc/config/i386/gnu-unwind.h > @@ -32,9 +32,100 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see > > #ifdef __x86_64__ > > -/* > - * TODO: support for 64 bits needs to be implemented. > - */ > +#define MD_FALLBACK_FRAME_STATE_FOR x86_gnu_fallback_frame_state > + > +static _Unwind_Reason_Code > +x86_gnu_fallback_frame_state > +(struct _Unwind_Context *context, _Unwind_FrameState *fs) > +{ > + static const unsigned char gnu_sigtramp_code[] = > + { > + /* rpc_wait_trampoline: */ > + 0x48, 0xc7, 0xc0, 0xe7, 0xff, 0xff, 0xff, /* mov $-25,%rax */ > + 0x0f, 0x05, /* syscall */ > + 0x49, 0x89, 0x04, 0x24, /* mov %rax,(%r12) */ > + 0x48, 0x89, 0xdc, /* mov %rbx,%rsp */ > + > + /* trampoline: */ > + 0x5f, /* pop %rdi */ > + 0x5e, /* pop %rsi */ > + 0x5a, /* pop %rdx */ > + 0x48, 0x83, 0xc4, 0x08, /* add $0x8,%rsp */ > + 0x41, 0xff, 0xd5, /* call *%r13 */ > + > + /* RA HERE */ > + 0x48, 0x8b, 0x7c, 0x24, 0x10, /* mov 0x10(%rsp),%rdi */ > + 0xc3, /* ret */ > + > + /* firewall: */ > + 0xf4, /* hlt */ > + }; > + > + const size_t gnu_sigtramp_len = sizeof gnu_sigtramp_code; > + const size_t gnu_sigtramp_tail = 7; /* length of tail after RA */ > + > + struct stack_contents { > + void *sigreturn_addr; > + void *sigreturn_returns_here; > + struct sigcontext *return_scp; > + } *stack_contents; > + struct sigcontext *scp; > + unsigned long usp; > + > + unsigned char *adjusted_pc = (unsigned char*)(context->ra) + > + gnu_sigtramp_tail - gnu_sigtramp_len; > + if (memcmp (adjusted_pc, gnu_sigtramp_code, gnu_sigtramp_len)) > + return _URC_END_OF_STACK; > + > + stack_contents = context->cfa; > + > + scp = stack_contents->return_scp; > + usp = scp->sc_ursp; > + > + fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_rax - usp; > + fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_rdx - usp; > + fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_rcx - usp; > + fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_rbx - usp; > + fs->regs.reg[4].loc.offset = (unsigned long)&scp->sc_rsi - usp; > + fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_rdi - usp; > + fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_rbp - usp; > + fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_r8 - usp; > + fs->regs.reg[9].loc.offset = (unsigned long)&scp->sc_r9 - usp; > + fs->regs.reg[10].loc.offset = (unsigned long)&scp->sc_r10 - usp; > + fs->regs.reg[11].loc.offset = (unsigned long)&scp->sc_r11 - usp; > + fs->regs.reg[12].loc.offset = (unsigned long)&scp->sc_r12 - usp; > + fs->regs.reg[13].loc.offset = (unsigned long)&scp->sc_r13 - usp; > + fs->regs.reg[14].loc.offset = (unsigned long)&scp->sc_r14 - usp; > + fs->regs.reg[15].loc.offset = (unsigned long)&scp->sc_r15 - usp; > + fs->regs.reg[16].loc.offset = (unsigned long)&scp->sc_rip - usp; > + > + /* Register 7 is rsp */ > + fs->regs.cfa_how = CFA_REG_OFFSET; > + fs->regs.cfa_reg = 7; > + fs->regs.cfa_offset = usp - (unsigned long) context->cfa; > + > + fs->regs.how[0] = REG_SAVED_OFFSET; > + fs->regs.how[1] = REG_SAVED_OFFSET; > + fs->regs.how[2] = REG_SAVED_OFFSET; > + fs->regs.how[3] = REG_SAVED_OFFSET; > + fs->regs.how[4] = REG_SAVED_OFFSET; > + fs->regs.how[5] = REG_SAVED_OFFSET; > + fs->regs.how[6] = REG_SAVED_OFFSET; > + fs->regs.how[8] = REG_SAVED_OFFSET; > + fs->regs.how[9] = REG_SAVED_OFFSET; > + fs->regs.how[10] = REG_SAVED_OFFSET; > + fs->regs.how[11] = REG_SAVED_OFFSET; > + fs->regs.how[12] = REG_SAVED_OFFSET; > + fs->regs.how[13] = REG_SAVED_OFFSET; > + fs->regs.how[14] = REG_SAVED_OFFSET; > + fs->regs.how[15] = REG_SAVED_OFFSET; > + fs->regs.how[16] = REG_SAVED_OFFSET; > + > + fs->retaddr_column = 16; > + fs->signal_frame = 1; > + > + return _URC_NO_REASON; > +} > > #else /* ifdef __x86_64__ */ > > -- > 2.43.0 > >
Hi! Please note that emails to <thomas.schwinge@siemens.com>, or <thomas_schwinge@mentor.com> don't reach me anymore, and, at least for the time being, likewise for <thomas@codesourcery.com> -- <tschwinge@baylibre.com> is the new thing; see <https://baylibre.com/baylibre-expands-open-source-business-to-include-compiler-services/>. (Or use <thomas@schwinge.name>, <tschwinge@gnu.org>, <tschwinge@googlemail.com>, as before.) On 2024-03-01T02:33:10+0100, Samuel Thibault <samuel.thibault@gnu.org> wrote: > Flavio Cruz, le mer. 28 févr. 2024 22:59:09 -0500, a ecrit: >> Tested with some simple toy examples where an exception is thrown in the >> signal handler. >> >> libgcc/ChangeLog: >> * config/i386/gnu-unwind.h: Support unwinding x86_64 signal frames. >> >> Signed-off-by: Flavio Cruz <flaviocruz@gmail.com> > > Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Thanks, pushed as commit b7c4ae5ace82b81dafffbc50e8026adfa3cc76e7. Grüße Thomas
diff --git a/libgcc/config/i386/gnu-unwind.h b/libgcc/config/i386/gnu-unwind.h index 0751b5593d4..02b060ab4a5 100644 --- a/libgcc/config/i386/gnu-unwind.h +++ b/libgcc/config/i386/gnu-unwind.h @@ -32,9 +32,100 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #ifdef __x86_64__ -/* - * TODO: support for 64 bits needs to be implemented. - */ +#define MD_FALLBACK_FRAME_STATE_FOR x86_gnu_fallback_frame_state + +static _Unwind_Reason_Code +x86_gnu_fallback_frame_state +(struct _Unwind_Context *context, _Unwind_FrameState *fs) +{ + static const unsigned char gnu_sigtramp_code[] = + { + /* rpc_wait_trampoline: */ + 0x48, 0xc7, 0xc0, 0xe7, 0xff, 0xff, 0xff, /* mov $-25,%rax */ + 0x0f, 0x05, /* syscall */ + 0x49, 0x89, 0x04, 0x24, /* mov %rax,(%r12) */ + 0x48, 0x89, 0xdc, /* mov %rbx,%rsp */ + + /* trampoline: */ + 0x5f, /* pop %rdi */ + 0x5e, /* pop %rsi */ + 0x5a, /* pop %rdx */ + 0x48, 0x83, 0xc4, 0x08, /* add $0x8,%rsp */ + 0x41, 0xff, 0xd5, /* call *%r13 */ + + /* RA HERE */ + 0x48, 0x8b, 0x7c, 0x24, 0x10, /* mov 0x10(%rsp),%rdi */ + 0xc3, /* ret */ + + /* firewall: */ + 0xf4, /* hlt */ + }; + + const size_t gnu_sigtramp_len = sizeof gnu_sigtramp_code; + const size_t gnu_sigtramp_tail = 7; /* length of tail after RA */ + + struct stack_contents { + void *sigreturn_addr; + void *sigreturn_returns_here; + struct sigcontext *return_scp; + } *stack_contents; + struct sigcontext *scp; + unsigned long usp; + + unsigned char *adjusted_pc = (unsigned char*)(context->ra) + + gnu_sigtramp_tail - gnu_sigtramp_len; + if (memcmp (adjusted_pc, gnu_sigtramp_code, gnu_sigtramp_len)) + return _URC_END_OF_STACK; + + stack_contents = context->cfa; + + scp = stack_contents->return_scp; + usp = scp->sc_ursp; + + fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_rax - usp; + fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_rdx - usp; + fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_rcx - usp; + fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_rbx - usp; + fs->regs.reg[4].loc.offset = (unsigned long)&scp->sc_rsi - usp; + fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_rdi - usp; + fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_rbp - usp; + fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_r8 - usp; + fs->regs.reg[9].loc.offset = (unsigned long)&scp->sc_r9 - usp; + fs->regs.reg[10].loc.offset = (unsigned long)&scp->sc_r10 - usp; + fs->regs.reg[11].loc.offset = (unsigned long)&scp->sc_r11 - usp; + fs->regs.reg[12].loc.offset = (unsigned long)&scp->sc_r12 - usp; + fs->regs.reg[13].loc.offset = (unsigned long)&scp->sc_r13 - usp; + fs->regs.reg[14].loc.offset = (unsigned long)&scp->sc_r14 - usp; + fs->regs.reg[15].loc.offset = (unsigned long)&scp->sc_r15 - usp; + fs->regs.reg[16].loc.offset = (unsigned long)&scp->sc_rip - usp; + + /* Register 7 is rsp */ + fs->regs.cfa_how = CFA_REG_OFFSET; + fs->regs.cfa_reg = 7; + fs->regs.cfa_offset = usp - (unsigned long) context->cfa; + + fs->regs.how[0] = REG_SAVED_OFFSET; + fs->regs.how[1] = REG_SAVED_OFFSET; + fs->regs.how[2] = REG_SAVED_OFFSET; + fs->regs.how[3] = REG_SAVED_OFFSET; + fs->regs.how[4] = REG_SAVED_OFFSET; + fs->regs.how[5] = REG_SAVED_OFFSET; + fs->regs.how[6] = REG_SAVED_OFFSET; + fs->regs.how[8] = REG_SAVED_OFFSET; + fs->regs.how[9] = REG_SAVED_OFFSET; + fs->regs.how[10] = REG_SAVED_OFFSET; + fs->regs.how[11] = REG_SAVED_OFFSET; + fs->regs.how[12] = REG_SAVED_OFFSET; + fs->regs.how[13] = REG_SAVED_OFFSET; + fs->regs.how[14] = REG_SAVED_OFFSET; + fs->regs.how[15] = REG_SAVED_OFFSET; + fs->regs.how[16] = REG_SAVED_OFFSET; + + fs->retaddr_column = 16; + fs->signal_frame = 1; + + return _URC_NO_REASON; +} #else /* ifdef __x86_64__ */
Tested with some simple toy examples where an exception is thrown in the signal handler. libgcc/ChangeLog: * config/i386/gnu-unwind.h: Support unwinding x86_64 signal frames. Signed-off-by: Flavio Cruz <flaviocruz@gmail.com> --- libgcc/config/i386/gnu-unwind.h | 97 ++++++++++++++++++++++++++++++++- 1 file changed, 94 insertions(+), 3 deletions(-)