On Tue, Sep 01, 2026 at 06:06:46PM +0100, Mark Brown wrote: > The fp-stress load programs all start up with some startup code which > installs signal handlers and fetches and reports the current PID into > x20. In order to facilitate running as KVM guests and reduce duplication > factor this code out into a asm-utils-linux.S, making the per-test entry > point main() similarly to more normal environments. As the > irritator_handler varies per test they are left in place. > > Since the PID is now reported before main() runs it is printed before > rather than after the vector length for those programs that report one, > fp-stress does not parse the output so this has no impact. > > Since asm-utils is also used by fp-pidbench that also gets converted to > the new _start implementation, this will install some signal handlers > that were not previously there and report a PID which was not previously > reported but should otherwise have no impact. Since it does not need an
You're adding enable_gcs to fp-pidbench too, maybe worth mentioning as well? > irritator none is provided and a weak definition left in > asm-utils-linux.S, this will end up as 0 which happens to be SIG_DFL > which is what we would have anyway. Hm I'm a bit confused by the SIG_DFL thing here? You directly check for 0 if irritator_handler is not available? > > Signed-off-by: Mark Brown <[email protected]> Aside from commit message nits I've had a good dig through here and it LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) <[email protected]> > --- > tools/testing/selftests/arm64/fp/asm-utils-linux.S | 87 > ++++++++++++++++++++++ > tools/testing/selftests/arm64/fp/fp-pidbench.S | 6 +- > tools/testing/selftests/arm64/fp/fpsimd-test.S | 76 +------------------ > tools/testing/selftests/arm64/fp/sve-test.S | 76 +------------------ > tools/testing/selftests/arm64/fp/za-test.S | 75 +------------------ > tools/testing/selftests/arm64/fp/zt-test.S | 75 +------------------ > 6 files changed, 106 insertions(+), 289 deletions(-) > > diff --git a/tools/testing/selftests/arm64/fp/asm-utils-linux.S > b/tools/testing/selftests/arm64/fp/asm-utils-linux.S > index 9cd31dc47709..9519be4d8f1e 100644 > --- a/tools/testing/selftests/arm64/fp/asm-utils-linux.S > +++ b/tools/testing/selftests/arm64/fp/asm-utils-linux.S > @@ -92,3 +92,90 @@ function exit_error > svc #0 > endfunction > .globl exit_error > + > +// Install a signal handler > +// > +// w0: signal number > +// x1: sa_action > +// w2: sa_flags > +// Clobbers x0-x6,x8 > +function setsignal > + str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! > + > + mov w4, w0 > + mov x5, x1 > + mov w6, w2 > + > + add x0, sp, #16 > + mov x1, #sa_sz > + bl memclr > + > + mov w0, w4 > + add x1, sp, #16 > + str w6, [x1, #sa_flags] > + str x5, [x1, #sa_handler] > + mov x2, #0 > + mov x3, #sa_mask_sz > + mov x8, #__NR_rt_sigaction > + svc #0 > + > + cbz w0, 1f > + > + puts "sigaction failure\n" > + b exit_error > + > +1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) > + ret > +endfunction > +.globl setsignal LGTM, I went through manually and confirmed that this is verbatim what every other setsignal function was doing. > + > +// Programs which want to be interrupted by SIGUSR1 provide an > +// irritator_handler(), for those that don't the signal is left alone. > +.weak irritator_handler > + > +// Main program entry point. Install the signal handlers shared by the > +// programs, zeroing the signal count in x23 that the handlers maintain, > +// read and report the PID the programs use for uniqueness in x20, then > +// run the program specific main(). > +.globl _start > +function _start > + enable_gcs > + > + mov x23, #0 // signal count > + > + mov w0, #SIGINT > + adr x1, terminate_handler > + mov w2, #SA_SIGINFO > + bl setsignal > + > + mov w0, #SIGTERM > + adr x1, terminate_handler > + mov w2, #SA_SIGINFO > + bl setsignal > + > + // Load as a literal, adr can't reference the symbol when the > + // program provides no handler and it resolves to 0 > + ldr x1, =irritator_handler > + cbz x1, 1f > + mov w0, #SIGUSR1 > + mov w2, #SA_SIGINFO > + orr w2, w2, #SA_NODEFER > + bl setsignal Looking through the code, I confirmed by hand that _start is the same everywhere except for this block. Before this was: mov w0, #SIGUSR1 adr x1, irritator_handler mov w2, #SA_SIGINFO orr w2, w2, #SA_NODEFER bl setsignal So the delta is: - mov w0, #SIGUSR1 - adr x1, irritator_handler + ldr x1, =irritator_handler + cbz x1, 1f And also you've marked irritator_handler as .weak, So my understanding is 'adr' loads irritator_handler as a relative offset in x1, but since you need to check for zero due to .weak, that can't work, hence the ldr, and the = just puts the absolute address of irritator_handler in x1. The 'cbz x1, 1f' is compare + branch if zero, and the 1f is 'next 1 label' i.e. look forward for it, which is just below. > + > +1: mov w0, #SIGUSR2 > + adr x1, tickle_handler > + mov w2, #SA_SIGINFO > + orr w2, w2, #SA_NODEFER > + bl setsignal > + > + // Obtain our PID, to ensure test pattern uniqueness between processes > + mov x8, #__NR_getpid > + svc #0 > + mov x20, x0 > + > + puts "PID:\t" > + mov x0, x20 > + bl putdecn > + > + b main And ack on what you mention in the commit msg, the PID output comes first but necessary to hoist that up into the linux-specific bits. And obviously then -> main for the rest of it. > +endfunction > diff --git a/tools/testing/selftests/arm64/fp/fp-pidbench.S > b/tools/testing/selftests/arm64/fp/fp-pidbench.S > index 881dfa3b342e..80f45560290d 100644 > --- a/tools/testing/selftests/arm64/fp/fp-pidbench.S > +++ b/tools/testing/selftests/arm64/fp/fp-pidbench.S > @@ -28,9 +28,9 @@ > puts "\n" > .endm > > -// Main program entry point > -.globl _start > -function _start > +// Program specific main function > +.globl main > +function main > puts "Iterations per test: " > mov x20, #10000 > lsl x20, x20, #12 > diff --git a/tools/testing/selftests/arm64/fp/fpsimd-test.S > b/tools/testing/selftests/arm64/fp/fpsimd-test.S > index fcbb3a872490..df040283d076 100644 > --- a/tools/testing/selftests/arm64/fp/fpsimd-test.S > +++ b/tools/testing/selftests/arm64/fp/fpsimd-test.S > @@ -148,69 +148,11 @@ function irritator_handler > > ret > endfunction > +.globl irritator_handler > > -// w0: signal number > -// x1: sa_action > -// w2: sa_flags > -// Clobbers x0-x6,x8 > -function setsignal > - str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! > - > - mov w4, w0 > - mov x5, x1 > - mov w6, w2 > - > - add x0, sp, #16 > - mov x1, #sa_sz > - bl memclr > - > - mov w0, w4 > - add x1, sp, #16 > - str w6, [x1, #sa_flags] > - str x5, [x1, #sa_handler] > - mov x2, #0 > - mov x3, #sa_mask_sz > - mov x8, #__NR_rt_sigaction > - svc #0 > - > - cbz w0, 1f > - > - puts "sigaction failure\n" > - b exit_error > - > -1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) > - ret > -endfunction > - > -// Main program entry point > -.globl _start > -function _start > - enable_gcs > - > - mov x23, #0 // signal count > - > - mov w0, #SIGINT > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGTERM > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGUSR1 > - adr x1, irritator_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > - mov w0, #SIGUSR2 > - adr x1, tickle_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > +// Program specific main function > +.globl main > +function main > // Sanity-check and report the vector length > > mov x19, #128 > @@ -231,16 +173,6 @@ function _start > bl putdec > puts " bits\n" > > - // Obtain our PID, to ensure test pattern uniqueness between processes > - > - mov x8, #__NR_getpid > - svc #0 > - mov x20, x0 > - > - puts "PID:\t" > - mov x0, x20 > - bl putdecn > - > mov x22, #0 // generation number, increments per iteration > .Ltest_loop: > > diff --git a/tools/testing/selftests/arm64/fp/sve-test.S > b/tools/testing/selftests/arm64/fp/sve-test.S > index 88c3220caf7c..c7d9514f964e 100644 > --- a/tools/testing/selftests/arm64/fp/sve-test.S > +++ b/tools/testing/selftests/arm64/fp/sve-test.S > @@ -316,69 +316,11 @@ function irritator_handler > > ret > endfunction > +.globl irritator_handler > > -// w0: signal number > -// x1: sa_action > -// w2: sa_flags > -// Clobbers x0-x6,x8 > -function setsignal > - str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! > - > - mov w4, w0 > - mov x5, x1 > - mov w6, w2 > - > - add x0, sp, #16 > - mov x1, #sa_sz > - bl memclr > - > - mov w0, w4 > - add x1, sp, #16 > - str w6, [x1, #sa_flags] > - str x5, [x1, #sa_handler] > - mov x2, #0 > - mov x3, #sa_mask_sz > - mov x8, #__NR_rt_sigaction > - svc #0 > - > - cbz w0, 1f > - > - puts "sigaction failure\n" > - b exit_error > - > -1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) > - ret > -endfunction > - > -// Main program entry point > -.globl _start > -function _start > - enable_gcs > - > - mov x23, #0 // Irritation signal count > - > - mov w0, #SIGINT > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGTERM > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGUSR1 > - adr x1, irritator_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > - mov w0, #SIGUSR2 > - adr x1, tickle_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > +// Program specific main function > +.globl main > +function main > #ifdef SSVE > puts "Streaming mode " > smstart_sm > @@ -404,16 +346,6 @@ function _start > bl putdec > puts " bits\n" > > - // Obtain our PID, to ensure test pattern uniqueness between processes > - > - mov x8, #__NR_getpid > - svc #0 > - mov x20, x0 > - > - puts "PID:\t" > - mov x0, x20 > - bl putdecn > - > #ifdef SSVE > smstart_sm // syscalls will have exited streaming mode > #endif > diff --git a/tools/testing/selftests/arm64/fp/za-test.S > b/tools/testing/selftests/arm64/fp/za-test.S > index 4a5b4b37d475..a0165a81a937 100644 > --- a/tools/testing/selftests/arm64/fp/za-test.S > +++ b/tools/testing/selftests/arm64/fp/za-test.S > @@ -161,69 +161,11 @@ function irritator_handler > > ret > endfunction > +.globl irritator_handler > > -// w0: signal number > -// x1: sa_action > -// w2: sa_flags > -// Clobbers x0-x6,x8 > -function setsignal > - str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! > - > - mov w4, w0 > - mov x5, x1 > - mov w6, w2 > - > - add x0, sp, #16 > - mov x1, #sa_sz > - bl memclr > - > - mov w0, w4 > - add x1, sp, #16 > - str w6, [x1, #sa_flags] > - str x5, [x1, #sa_handler] > - mov x2, #0 > - mov x3, #sa_mask_sz > - mov x8, #__NR_rt_sigaction > - svc #0 > - > - cbz w0, 1f > - > - puts "sigaction failure\n" > - b exit_error > - > -1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) > - ret > -endfunction > - > -// Main program entry point > -.globl _start > -function _start > - enable_gcs > - > - mov x23, #0 // signal count > - > - mov w0, #SIGINT > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGTERM > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGUSR1 > - adr x1, irritator_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > - mov w0, #SIGUSR2 > - adr x1, tickle_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > +// Program specific main function > +.globl main > +function main > puts "Streaming mode " > smstart_za > > @@ -247,15 +189,6 @@ function _start > bl putdec > puts " bits\n" > > - // Obtain our PID, to ensure test pattern uniqueness between processes > - mov x8, #__NR_getpid > - svc #0 > - mov x20, x0 > - > - puts "PID:\t" > - mov x0, x20 > - bl putdecn > - > mov x22, #0 // generation number, increments per iteration > .Ltest_loop: > rdsvl 0, 8 > diff --git a/tools/testing/selftests/arm64/fp/zt-test.S > b/tools/testing/selftests/arm64/fp/zt-test.S > index 82a76bb2307a..1c7db1298fb1 100644 > --- a/tools/testing/selftests/arm64/fp/zt-test.S > +++ b/tools/testing/selftests/arm64/fp/zt-test.S > @@ -130,80 +130,13 @@ function irritator_handler > > ret > endfunction > +.globl irritator_handler > > -// w0: signal number > -// x1: sa_action > -// w2: sa_flags > -// Clobbers x0-x6,x8 > -function setsignal > - str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! > - > - mov w4, w0 > - mov x5, x1 > - mov w6, w2 > - > - add x0, sp, #16 > - mov x1, #sa_sz > - bl memclr > - > - mov w0, w4 > - add x1, sp, #16 > - str w6, [x1, #sa_flags] > - str x5, [x1, #sa_handler] > - mov x2, #0 > - mov x3, #sa_mask_sz > - mov x8, #__NR_rt_sigaction > - svc #0 > - > - cbz w0, 1f > - > - puts "sigaction failure\n" > - b exit_error > - > -1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) > - ret > -endfunction > - > -// Main program entry point > -.globl _start > -function _start > - enable_gcs > - > - mov x23, #0 // signal count > - > - mov w0, #SIGINT > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGTERM > - adr x1, terminate_handler > - mov w2, #SA_SIGINFO > - bl setsignal > - > - mov w0, #SIGUSR1 > - adr x1, irritator_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > - mov w0, #SIGUSR2 > - adr x1, tickle_handler > - mov w2, #SA_SIGINFO > - orr w2, w2, #SA_NODEFER > - bl setsignal > - > +// Program specific main function > +.globl main > +function main > smstart_za > > - // Obtain our PID, to ensure test pattern uniqueness between processes > - mov x8, #__NR_getpid > - svc #0 > - mov x20, x0 > - > - puts "PID:\t" > - mov x0, x20 > - bl putdecn > - > mov x22, #0 // generation number, increments per iteration > .Ltest_loop: > mov x0, x20 > > -- > 2.47.3 > -- Cheers, Lorenzo
